no voltage to a/c clutch

[budwich]

you don't have to worry about any relays, etc and forget odb, it ain't going to help you with wiring. Anyways, another question, you have the manual AC/heating system as opposed to the EATC system right??? IF you have a manual system, you are going to have to "break in" to the dash / panel and get at the switch selector and see if you have voltage coming into there... it comes from the fuse and goes thru the switch on its way to the low pressure switch... so that's the next good place to look / check.

 

[thor1701]

mine is all digital, i press the max ac button, it takes a moment to start blowing, and sometimes when i do that the idle goes up slightly but then goes right back down to normal, even with the clutch unplugged

 

[budwich]

ooh ooh... that's a different "fish", probably should have mentioned that earlier. You need to probably see if you can get the digital control to go into "diagnostic mode" and see what it says.... of course, search is your friend for finding out how to do that (I got a manual system).

further related to this... you checked ALL your fuses as there are a "few" with this system.

 

[thor1701]

i wouldnt even know what to search for on that one

 

[bobflood]

OK - I had this exact problem last year. Did much of what you did and got fooled by using a multimeter instead of a test light for checking voltage. Those tests made me think that I had voltage all the way thru to the plug - trouble was, there was just enough current to signal the multimeter, but not enough to do any "work" - i.e. activate the relay or turn on a test light. I spent hours of frustration doing what you have done!!

However, to cut to the chase. There is a relay on the circuit board in the EATC head unit that energizes the clutch relay. The solder joints on that relay weaken, so the unit won't put out enough current to work the clutch relay. It can be resoldered - I was able to do that - but it requires pulling out and disassembling the EATC unit itself. If you want to do that, pull the EATC unit, disassemble; and look for a small black box on the circuit board - that is the relay, only thing like it there. Resolder the connections, reassemble, hook it up, and see if problem goes away. I found a thread here with better instructions, but don't remember where it is; try searching for "EATC.".

Plan B is to go on line and search for rebuilt EATC units; they are commonly available for about $100. I found a shop here in Atlanta that sells them. Good luck.

 

[thor1701]

im assuming the eatc is the digital thing with the buttons and whatnot for the ac?

 

[thor1701]

ouch i found it on ebay for 99, damn even there its expensive, would putting it in diagnostic mode tell me anything? i just found out which buttons to press, just need to get out there and do it, just woke up, having my coffee, ie mt dew

 

[bobflood]

ouch i found it on ebay for 99, damn even there its expensive, would putting it in diagnostic mode tell me anything? i just found out which buttons to press, just need to get out there and do it, just woke up, having my coffee, ie mt dew

Can't hurt, but the problem I described will nto show up via diagnosis.

 

[thor1701]

i will check it out and see what i find tho but yeah couldnt hurt to do the diagnostic since i seem to run out of options lol

 

[bobflood]

This is the thread that lead me to the solution of re-soldering the relay inside the EATC unit itself.

http://www.explorerforum.com/forums/showthread.php?t=363745

Here are the words "noremarks" PMed me:
"Relay for AC
-------------------------------------------------------------------------
If you have a Electronic Automatic Temperature Control, the relay is located on the electronics board of the control head. (the unit that turns up and down the heat and controls where the air comes out) That is all one unit, that should comes out pretty easy. carefully disassemble down to the board mine only had one realy, (a black large plastic box soldered on to the board). there might be a solder joint on the bottom of the board that may look burnt or dull to the eyes. If you take a magnifying glass to the dull joint you should see that it no longer makes contact. I took and re-soldered the pin, (careful not to much heat). and was back in business again. Good Luck."

This worked for me - and was easier to do than I expected.

 

[thor1701]

well it looks like that was the issue, i have not fixed it yet but while running the truck and having the controlls hanging out and open, i turned on the ac button, no voltage, so i applied some pressure to the relay, omg i had 13 volts on the meter, can ya believe that?? lol so i will take a little break and re solder the connections to it and see if that fixes it, now i just have to find my stupid iron, its been a while lol

 

[bobflood]

Great news!! Yeah - it took me longer to find my old iron than it did to fix the darn thing!! It had been a long time since I had soldered anything. Glad you got it fixed!

 

[thor1701]

took me forever to find the iron and i usually keep it in a certain place, anyways yes a few of the spots looked kinda dull, so i just added a little more to them and made them all shiny, i would have NEVER figured this one out honestly thank you so much, so its back in and all is well, tho looks like i might have to charge it a little as it cycles on and off quickly, now my next project will be to find out which is the best spark plug for my truck, i've had it a few years now and her vibrations are alittle off so im thinking its time for a tuneup, i just want the best plug that will get me the best mpg as gas is quite high here now

 

[thor1701]

welp, after all this time it looks like that relay is the issue again, this time i re soldered everything, still did not want to work, so i just want to replace the entire thing, but they are still very expensive for a match, im wondering, are there interchangeable one's? i see one on ebay that is a match, the only difference is, where it would turn on the rear fan, it has "outside temperature" on it, would it still work the same way?