Phase 2 InstallationNEWS! The how-to is completed. I will update/revise over time but what you need is here!This how-to will help you because both Ryan and Bob went to WAY more trouble than is necessary to get their install done because they didn't have the shortcuts. Unnecessary things they did are take loose the ENTIRE dashboard and run separate wires for the fan controller, including in one case drilling through the firewall and adding a grommet!Although these are WONDERFULLY ambitious (and successful!) efforts that got them ahead of everyone else doing this (well, but me anyway) -- there are easier ways.The following tricks will be revealed:1. Painless installation of the blend door servo (relatively). There are some problems you can run into and I've got it nailed to where you won't be taking long at all to do it -- and you won't have to move the dashboard.2. Reusing the old resistor wiring for the new fan speed controller. This means you run NO extra wires to the front other than what I've had you do in Phase 1 of the install and you DEFINITELY need not drill the firewall. There are some "gotcha's" doing this so wait for the how-to -- particularly if you have a pre-2001 truck. But even newer ones have a junction that must be cut near the fan to keep from a short circuit. It's easy and painless as long as you know you have to do it!Again, my sincere congratulations and appreciation to Ryan and Bob for their outstandingly agressive pursuit of this install! Still, I have some tricks to make it easier if some of you want to wait a LITTLE bit longer! ;-)PLEASE NOTE: As you begin this phase, you must continue to the end or you will have no heating/air conditioning. Also, if you skipped the "bench testing" procedure on page 17 you are taking a chance of ending up with something that doesn't work. Again, I recommend you test everything before installing it. Also, it is wise to unhook your battery. I don't do it, and perhaps you'll choose not to -- but if you do you'll need to be very careful when working in the dash, and you must not turn your key on until the ENTIRE install is completed. Turning on the power with things only partially installed could damage EATC components.Fan Controller WiringAs I said, it is possible to wire the fan controller using existing wires. What stands in our way is the way wires have been spliced together in the harness -- but it's fairly easy to remedy.Begin by removing the cruise control servo again in order to make room to work. Unplug the electrical harness from it so that you have plenty of slack to work with it and place the cruise servo over the intake manifold somwhere. If you've not done the preliminary work for this, consult the phase 1 installation instructions. Below left is the servo installed and the red arrow points to the bolt to remove. Below left is the servo placed out of the way on the intake manifold. Note that you don't need to remove the cable that goes to the throttle, just the electrical connector.Basically, there are three parts of this: wiring the controller to the existing harness, wiring the fan to the controller and grounding the controller to the truck.2001 wiringReally, pretty simple. There are three wires that go from behind the dash to the existing fan in your truck and they can be used to run the three signals we need out to the fan speed controller. One branches to both the fan and the resistor, but we're going to remedy that.First, unplug the connector from the fan motor. Next, untape the branch of the harness that feeds the fan all the way back to where it joins the rest of the wiring harness. Usually, it's easier to carefully slit it with a sharp knife or razor. You will expose two wires: WH/PK and OR/BK. Now, cut the OR/BK wire where it joins the main harness leaving as much wire on the fan connector as possible. DO NOT CUT THE WH/PK WIRE. Wrap some electrical tape or use liquid tape to insulate the end of the cut wire in the main harness.Remove your old resistor from the fan housing. Unplug it and set it aside. It will sone be a useless thing and you can just throw it away unless you know someone who needs one.Now, brace yourself -- cut off the plug from the resistor harness right at the plug leaving no wire on the plug. When I did this on Carl's truck (the first guy I did this for), he was worried because we had nothing left to splice the resistor connector back in if it didn't work! Oh, faithless people! We will make this work IF you tested all your hardware and it worked. We had tested his.If necessary, peel down, unwrap or slit the harness taping to expose enough wire to work with.You now have 4 wires free. One is 12 gauge (OR/BK), and the other three are 14 gauge. Here's what you have:OR/BK - 12 gauge (thicker) wireYE/RD - 14 gauge wireLG/WH - 14 gauge wire(2001 up only) BK - 14 gauge wire (we won't be using this one, it's too thin for a full ground for the speed controller)('95-'00 only) RD/OR - 14 gauge wire (similar to the 2001 , we won't be using this wire either. Make sure it's taped off.)Now take a 2 foot piece of 10 gauge wire and using a yellow butt splice, connect it to the black wire coming out of the speed controller. On the other end of this wire, crimp a yellow "ring terminal". This is a terminal with a hole in it. You need one with about a 1/4" hole to go on an existing ground lug. Route this wire to the passenger side fender, and you will find a ground lug with a strap already attached on the fender next to the blower motor housing. Remove the nut and put this terminal on the stud, then replace and tighten the nut. I realize I show the controller mounted in this photo, but you don't need to have it mounted as you do this and it is easier to NOT have it mounted. Below left is the splice of the wire to the controller, and below right you can see the ground bolt. In most trucks it's tinted green and the green arrow is pointing to it. It's shown with the servo still in place (black bracket in the foreground).Using blue butt splices (or solder and sleeve if you're ambitious), connect the wires from the harness to the wires of the fan speed controller as follows:OR/BK (truck) --> BR/OR (controller)YE/RD (truck) --> TN/OR (controller)LG/WH (truck) --> WH/PK (controller)The picture above shows all the wires terminated, but it's just for illustration. I think I also used a different combination of wires on that unit -- but use the combinations I'm giving you here. I was sort of "winging it" on the early installs, but I've standardized what wire combinations are used with this how-to.When you terminate the trucks 12 OB/BK wire, you may have a problem getting it into the blue splice. If so, peel back and cut a few strands of the wire so that you have a smaller bundle to insert in the crimp. Test all crimps by tugging on them sharply. If they do no hold, they were bad and you must redo them.Plug the blower motor connector back into the motor. We're going to connect the OR/BK wire from the fan to the heavy 10 gauge OR/BK wire (or just OR on some units) coming out of the speed controller. However, we need to check if the wires reach or not so hold the speed controller in place in the fan housing and see if the OB/BK wire from the fan and the OR/BK wire from the speed controller will reach each other. If not, extend one or the other using a yellow butt splice.Finally, tie the speed controller OR/BK wire to the fan OR/BK wire (or extension) using a yellow butt splice.If you offroad especially, it's a good idea to seal all these splice ends with liquid electrical tape (best), or wrap each one very tightly with electrical tape. You can neaten up the harness however you like. There's a black wire we didn't use for a ground because it's too thin and you can just cut it back and tape or seal the end up.Mount the speed controller in the housing using a gasket or some kind of sealer. Replace the cruise control servo (don't forget to plug it back in) and you're done!1995 through 2000 wiringBasically the same as the 2001 wiring except that:A) You have no black wire on your resistor. It's RD/OR and you must insulate it from shorting to anything else because it's a "dual function" wire and we'll be using the other end inside the truck to control the fan relay.B) There may not be a ground lug in the same position as the one in the 2001 trucks. If there is not, simply find another good nearby ground that you can put the lug on and secure it well. If it's not intended to be a ground point, remove the paint directly under where the lug will go so that it makes good contact.Wasn't that all MUCH easier than drilling and running a new wire? I think so! I'm fundementally lazy, so I'm always looking for an easy way out!Mounting the Blend Door ServoFirst, remove the original servo. You need a small 1/4" ratchet and a 5/16" or 8mm socket. The socket needs to short enough to allow the screw to come all the way out because the gap is VERY small. Note in this picture the two sockets. One is a cheapy that is shorter (right) than the better socket (left) and it worked well. You can also take an old socket and cut it down since you're on a hex head screw and not on a nut with a shaft sticking out of it. However, don't cut it down TOO much as you have to come into the rear screw over the servo and you need enough length to reach the head of the screw.Those of you with 2001 and 2002 Rangers may have a cable controlled blend door. You can still do this mod, no worries. But taking out your old actuator is a bit different. Here you can see the climate controls and the two thin cables that go to the rotary actuator at the bottom of the picture. That actuator just clips onto a baseplate mounted in the same spot the servos would be. Push the tabs on the base plate out away from the rotary piece and it just pops off. Then you will remove the baseplate just as if it were a motor actuator -- only you've got a bit more room. Sorry, no picture of the baseplate -- I don't know what happened to it.Okay, now here's the deal: this EATC servo can be a real dog to mount. Getting the shaft into the hole in the blend door seemed impossible -- and it was. It turns out that it has to be turned a little because the servo has more travel than the blend door. Also, the blend door has a tendency to keep "falling" because of gravity and turning the keyed hole where the shaft has to go in. It helps to take the servo apart and preset the position of the shaft. This is not at all hard to do. If you're lucky enough to have everything end up where it should be and you can just drop it in -- great. But otherwise you're going to need the following procedure.To the right is a picture of a special servo I put together using parts from a white and black one to highlight the tabs that hold it together. Start on a corner and pry the tabs on either side of the corner away and slightly separate the two housing halves. Work you way all the way around and lift off the top (white half) of the servo carefully, leaving all the parts in the black half.What you'll end up with is more-or-less illustrated in the pictures below. These are leftover pieces from when I built my "hybrid" servo before and yours won't look quite like this one. Notice the position of the arc-shaped gear on the right of each picture. In the left hand picture it is tight against the case. In the right hand picture it has been rotated to make about a 1/4" gap between it and the housing. Just lift the center gear piece up a little bit, and you can rotate the drive shaft the protrudes outside the case to turn the arc gear. Once it's in place push the middle gear back in and snap the case back together carefully.Now put the servo down and reach up between the ducts where the servo mounts and find the circular area where the shaft will go in. You'll find that by sticking the end of your finger on it you can turn it this way or that. What you want to do is turn it fully counterclockwise (as if you were viewing it from the top). This will put it in the correct position to mount the servo.Once you've done that, position the servo up over the duct. Orient it shaft down so that the side with 3 mounting tabs (at the top of the pictures above) is towards the fire wall and the side with two mounting tabs is towards the seats. Rotate it around a bit after you get the shaft into the hole and it should drop in. Great! Now put the screws in starting with the ones closest to you. Don't tighten them completely, but enough so the servo doesn't rock around. Finally, carefully get the remaining screw farthest from you (it goes into the center tab back there) into place and tighten it. Tighten the other screws. DONE!Recapping where we are at this pointRight. You've passed the point of no return (when you started cutting connectors off) and we are now REALLY committed to this, like it or not!What you've done (or should have done) so far is:A) Installed all 3 sensors and brought the wires to the dash center (Phase 1)B) Installed and connected the aspirator tubing (Phase 1)C) Prepared the fan housing to accept the speed controller (Phase 1)D) Tapped into the vehicle network and brought that pair into the dash center (Phase 1)E) Pre-wired the auxiliary relays and mounted them on the head unit (Phase 1) -- Note: For some older truck configurations I have not completed the drawings for the relays. Specifically, how to use a 1995-1997 head unit with a 1995-2000 truck. Don't worry, I'll get to it!F) Mounted the fan controller and completed the under-hood wiring (Phase 2)G) Mounted the EATC version of the blend door servo (Phase 2)Final wiring in the dashboardThis means we're ready for the most exciting part, and the part where you could most easily make an error -- wiring the heat unit into the vehicle! This will turn into quite a "rat's nest" or maybe even a "bird's nest" as you do it! But you can clean it up when you're done and don't let it dismay you. We deliberatedly segregated our wiring groups on the head unit harness to help us take a systematic approach and not get confused. In particular, we will wire it so that the unswitched 12 volts, then switched 12 volts are the last things connected. This is particularly important if you leave the battery connected when you do this install. If you disconnect the battery, you can connect the wire groups in any order you please. So, take out your radio, your center dash bezel, and take off the 4 screws that hold in your old climate control panel (save the screws). Unclip and remove the vacuum harness connector, and all the electrical connectors. If you have a cable controlled blend door (2001 and 2002), then pull the cable out of the dash (you unhooked the other end already). It may require two hands and a bit of fishing to get it free. When you're done, you'll have something that looks more or less like this picture. Although the passenger airbag is shown removed, it's not necessary at this point. Most vehicles will have four electrical connectors, but 2001 and 2002 cable units have three.Move all connectors but the ones that went to the climate controls to the side and tape or tie them out of the way. Unplug the vacuum harness from the ductwork, accessing it from the glove compartment (you should have the glove compartment "dropped"). Again, don't remove the individual tubes, just pull the translucent blue rubber connector from the white hard plastic connector on the ductwork. There are two small retainer clips or tabs which hold the rubber piece to the white piece. To the right is a detail of the vacuum harness to ductwork connection. Remove the harness from the vehicle and don't forget it's "pegged" in using those white nylon retain pegs and you'll have to pull those loose.Now, cut the connectors off the wires that went to the climate control. Cut them right at the connector -- you're going to want enough slack to be able to crimp to them easily.Position the head unit, face down, against the center console with the connectors facing upward. You may want to put some paper over the face and tape it in place to keep it from getting scratched. It's a good idea to find a pillow, small box or something to put under the unit so that the connectors at the back are right at the level of where the unit will eventually mount. Some wires may be very short to reach and this helps.The two EASIEST connections you'll make are the vacuum connection (already made) and the actuator connections (which we prefabbed before testing). Go ahead and route those two connections through the center dash opening and over to the glove compartment area. If there is sufficient slack, go ahead and plug them in. That's easy, eh?GroundsWe'll connect the ground first to minimize the possibility of static buildup and the like. There is a heavy black wire that went to the fan speed switch that is the main ground for our application. However, it's a 10 gauge wire so you need a yellow butt splice for it. Crimp on end of the splice onto the big black wire from the trucks harness.We may be putting several wires in the other end of the splice, but they are not so thick. So when you have to put a small wire in a large splice, strip it back twice as far (1/2" to 5/8") and double it back on itself to leave about a 1/4" bare end. It will crimp more securely that way. You will have to use the blue section of the crimp tool, or even the red, to get the crimp tight enough. If you use the yellow section of the crimper with and undersized wire -- it won't hold.Take the black wire from the "Power and Ground" group, and combine it with the extra ground from your actuator harness if you have a pre-1998 actuator. Also, if you have a 1995-2000 truck with a pre-1998 EATC head unit, you will have a ground coming from the auxilliary fan relay (see previous page, if I finished the diagrams). Also, if you want a celsius units display, include the red wire from the console as well. Strip all these back longer, double them over, and insert then into the other end of the yellow butt splice and crimp. If you have a newer actuator and a 1998 or later head unit, you will have only the one wire.Fan controller wiringPretty easy -- we only have 3 wires to terminate. For two of them you will use red butt splices. However, one is pretty big (OR/BK) so you will need to do the doubling over thing because you need a yellow butt splice. Again, it will help ensure a good crimp in the big yellow splice. Sometimes I take a bit wire and trim some strands after it's stripped and fit it into a blue crimp when it's not going to carry current. It's another alternative if you like.So, this is a lot like what we did under the hood. Connect the EATC wires from the "Fan relay and speed control" bundle as follows:OR/BK (truck) --> BR/OR (EATC head unit)YE/RD (truck) --> TN/OR (EATC head unit)LG/WH (truck) --> WH/PK (EATC head unit)Vehicle network wiringConnect the two wires from the vehicle network (they were in the Miscellaneous group) to the wires you used to extend up from the diagnostic connector. Use red butt splices. Remember, you were going to write down which wire color of the ones you extended went to which wire color under the dash. Take care to connect the two wires coming from the head unit so that they match the same color wires under the dash. This is VERY important.The wires in the head unit harness are usually twisted together and they are:TN/OR and PK/LB - twisted pair for network tie in (1996 up only)Dimmer wiringTake the LB/RD and RD/BK wires from the "Miscellaneous" group, strip them back 3/8" and twist them together. Connect them to the LB/RD wire from the truck harness using a red butt splice. The LB/RD wire in the truck was paired with a black wire which will not be use so you can just tape it off.Sensor wiringWhen you installed the sensors, you ran a pair of wires to each of the 3 sensors. Now we'll bring them together and tie them in.For all sensors except the sunload, polarity is insignificant (I'm not convinced it's important for the sunload either, but let's act as if it is). What you will do is strip the leads that go to the PK/BK wire on the sunload sensor, and one of the wires from each of the other sensors, and strip the back 3/8". Now twist them together and see if you can get them properly into a blue but splice. Depending on what wire size you use this may be impossible. In that case use a yellow one. Crimp whichever butt splice you select to this junction of the three wires.Now connect the other end of this splice to the PK/BK wire in the "Sensors" group in the EATC harness. Do the "doubling" think if you used a yellow crimp and crimp it down hard and remember not to use the yellow section of the crimper when crimping undersized wires.Now tie in the signal wires from each sensor using a red butt splice.RD/OR - splice to ambient (outside) temperature sensorBR - splice sunload sensorWH/OR - splice to in car (cabin) temperature sensorTieing in the compressor clutch and fan control wiresFor all trucks, you should have a relay for the compressor clutch which was pre-wired. Strip and crimp an insulated female spade terminal on the PU wire coming from the trucks harness and put it on the remaining terminal on your A/C compressor relay.If you have a 2001 truck with a 1998 head unit, you also have another relay for the fan power. Strip and crimp an insulated female spade terminal on the RD/OR wire coming from the trucks harness and put it on the remaining terminal of your fan power relay. If you have a 1995-2000 truck, and a pre-1998 head unit, you also have a second relay (though it's wired differently) and you should connect your RD/OR wire to your remaining relay the same way.If you have a 2001 truck and have a pre-1998 head unit, or have chosen not to use a relay, then connect the RD/OR wire in the truck harness to the GY/YE wire in the truck harness using a red butt splice. This connection doesn't involve any wires from the EATC.If you have a 1995-2000 truck and a 1998 head unit then you have only one relay required. Simply connect the YE/BK wire coming from the EATC to the RD/OR wire in the truck harness. This is the only configuration where the trucks existing fan power control relay can be controlled directly.Switched 12 volts connectionNow you will bring these EATC wires together into one end of of a splice and it may need to be a yellow one if you have a lot of these in your configuration:RD - English/Metric (only if you want Fahrenheit units)BK/LG - "hot in run" (switched 12 volts)WH/PU - "hot in run" (1995-1997 only)??? - the 12 volt power wire coming from your actuator if you have a pre-1998 actuator??? - the 12 volt power wire coming from your auxilliary relaysNow crimp the other end to the BK/LG wire coming from the truck harness. Double over and crimp this end appropriately if the butt splice is oversized.Constant 12 volt powerFinally, the last wire is the constant 12 volt power (LG/YE). Crimp about an 8" extension onto this wire using a red butt splice. Run this wire to the connector that was plugged into the back of your radio.Now, using a blue tap connector, tie it to the LG/PU wire on the radio harness. You may have to cut/peel back the wraps on the radio connector harness to make enough wire available to put the tap on it. NOTE: THIS WIRE IS ALWAYS HOT! IF YOU HAVE NOT DISCONNECTED THE BATTERY, BE CAREFUL NOT TO SHORT IT TO GROUND WHEN TAPPING.Now what?I HIGHLY recommend reviewing what you've done to make sure there are no bad crimps that came apart, bare wires exposed, or wiring errors. If you're sure you did it right, you're ready to test!Testing, 1-2-3-4...Place the EATC unit loosely in the dash so you can see the display. Turn the key to the ON position, but don't start the truck yet. The display should flash briefly with everything lit up, then go blank. This is good.Now start the vehicle. Again, the flash perhaps, then blank. Now press the AUTO button. The display lights up with "Auto" and the default temperature (usually 75 not 72 as I previously stated). The fan will not start instantly. It should ramp quickly up to speed after about a 5 to 10 second delay if it's hot out. It will be longer if it's cold and you are asking for heat.If the fan does not start, press "MAX A/C" -- it should ramp up to maximum.Play with the buttons selecting different places for the air to come out and verify that it works. Use the red and blue buttons to change the temperature above and below the air temperature in the vehicle to force it to heat or cool and observe the result. Cycle the wheel to manually change fan speeds. If it all works -- you're good to go!Finally, do the self test diagnostic I described in preliminary testing. Let the unit go through it and see if there are any error codes. If not, great! If so, troubleshoot your wiring job.The EndIf it all works, neaten up your wiring and mount the head unit using the screws that held your old climate controls in. It will fit tight with the wire bundles in the back resisting it being pushed in, but the screws will tighten it down.Put your truck back together and enjoy the beauty and function of your exciting new mod!Check back for edits and revisions -- but you have what you need now. Email me if you really need to and I'll try to help you. Be blessed and best success!
