A/C problems....

[toddious]

Thanks for the clarification on the relays. First.... no the compressor cycling has no way of stopping your front fan from working (I think...). The cycling on the compressor is another problem which as stated is likely low freon levels.

Back to your fan... no the relay box is not bad (unlikely)... what it means is you are not getting the right "conditioning" to cause the relays to operate to cause the fan to operate... understand??? In your EATC case, there is only one relay (sorry about very early posts which I thought was about "basic air conditioning / heating"). That relay is the blower motor relay (aux relay box #2). It operates when you key is in run. There should be 12 v on BK/LG and ground on BK wires at that box when your key is in "run". The relay should operate (ie. you should hear a click there but verify with a meter). That is straight forward and a "go / no go" condition. The "switch contacts" of that relay cause the blower motor to get "power". This power (12v) is another BK/LG wire and comes out of the relay on PK/W to your blower motor. This should also be checked.... before operation 12 V on BK/LG and 0 on PK/W and when operated 12V on PK/W. If you do not see this, your blower motor has no chance of running. If you do see this, then all that is left in the circuit is the blower motor (could be bad... I doubt it but...) and the blower speed controller which could be bad (good candidate) but not necessarily as it gets its "commands" from your EATC control module. Hope you can follow this. Having said the above, there is some possibility that your cycling compressor "status" might be feedback to your EATC control module via the PCM (power control module) which "appears" to have some "knowledge" of such events.... I don't know about this .... just my "interpretation" of the schematics.

As noted in the previous explanation, it is likely that your speed controller is a problem but you should check the states as mentioned before going there.... or if you want to throw some money around, just replace it and see if it solves your problem.

where could i test these wires to find out the voltage across them? do i need to splice into them? and i assume that BK=Black, LG=light green, PK=pink, and W=white?

i am not one to mess with automobile electronics all that much, all though i do have a DMM and would like to avoid replacing unnecessary parts. thanks for your help.

 

[budwich]

I have to admit that I have only done a little electric troubleshooting on my Ex since I bought it (used about 6 months ago) so I can't help much. I know that the relay box #2 is in a bad spot in terms of access. Usually most connectors on the back of boxs, etc have spaces on their back side where the wires go in with the "lug connectors" to push a "pin probe" from your DMM in to measure things. That is what I did on my aftermarket remote key entry install. In terms of this problem, if you can't access the back side, try removing the relay and measuring stuff from the topside. This would be in the "pre-conditioned" state. If you get the right things there (ie. 12v on one side and grd on the other) then the relay should operate when you plug it back it and you should hear the click when you do that... in essence you have tested (almost).

So with your key in run and the relay removed you should see 12v on two pins, one for the relay operation and one that will eventually be sent thru the relay to your motor. These will be measurable. Then put your relay back in... listen for the click. Then follow the PK/W to some where near your blower motor (sorry don't know where) but there should be a connector somewhere close to there on fire wall perhaps or by the motor (which is probably tough to get at). Hopefully you can look for 12 v there.

Your colors are correct assuming my reference (not official ford) is correct.

 

[toddious]

i have accessed panel #2, and its not a total PITA, but located under the intake, and a number of other wires that must be removed to gain access....

so, you're saying that i should hear a click from the relays when i kick on the A/C? whats the easist way to hear this "click"?

i'm going to get the a/c charged tomorrow, so that should at least make the compressor work (in theory). todd.

 

[budwich]

If you are lucky, you should be able to feel the "click" as you put the relay back in (assuming your key is in the "run" position at the time). Otherwise a straw might help or a coat hanger held against the relay and your ear while someone cycles the key from off to run.

From the drawing, the relay is pulled up with the key turned to "run"... ie. the normal position once your have started your truck (note you don't have to start to get to run).... your AC is not involved in causing the relay to operate.... the AC stuff only comes into play in getting the motor to run which is the next step. Make sure that you have the right relay (ie. the blower motor relay).

 

[Scareydad]

A slotted or flathead screwdriver works just as well for hearing internal sounds. Any rod of material that is solid will transfer sounds well to the ear canal. I have an 18" flat-head screwdriver with a busted end that I use for that purpose.

 

[kstrayhorn]

lol scarey, you're a little late to the convo, bud

 

[SRoberts006]

I am having the exact same problem on my 96 explorer, so just wondering if you ever got this fixed. And if so let me know what it was...