Compressor will not kick on

[Fedge]

Howdy, I have (once again) searched like crazy and I can't seen to find what I'm looking for.

I have a 98 Limited with the EATC and I get heat no matter what setting I have the control panel on. Everything works fine up to the compressor...where the problem lies. I have had the system evacuated, checked for leaks and recharged and that was fine. The compressor only kicked on when it was jumped at the compressor. I swapped all the relays...nothing. I replaced both the high and low pressure switches, still nothing. I am told that there is some sort of controller or thermal controller or something, but I cannot find the correct name for this part anywhere...

any help would be great! Thanks!

 

[BrooklynBay]

Maybe the module or the relay is no good? Did you check all of the fuses? What about the output from the automatic climate control switch assembly?

 

[Fedge]

Maybe the module or the relay is no good? Did you check all of the fuses? What about the output from the automatic climate control switch assembly?

all of the fuses and relays are good and I get power from the control switch assembly itself. It changes the blower motor speed, the blend air door and everything else it's supposed to do, the compressor just won't kick on. I confirmed that it worked by giving it +12 from the battery...but it won't do it on it's own. there is another part in the system, but I can not remember the correct name...i heard it is mounted in the right side fender area, but I haven't the foggiest what it is. Sometimes I miss my XLT, lol

 

[Fedge]

I wish I had a schematic. I guess I'll run down to the local parts store...pick up a 'service' manual (the Ford Tech manual is sooooooooooo much better lol)

 

[BrooklynBay]

Check Autozone's website for a schematic.

 

[KPT]

There is another part in the system, but I can not remember the correct name...i heard it is mounted in the right side fender area, but I haven't the foggiest what it is.

The low pressure switch is in that area. On top of the accumulator. But you said you've already replaced that? Did you try jumping that switch?

Have you verified that there is enough refrigerant in the system?

 

[Fedge]

Check Autozone's website for a schematic.

thanks, I will!

 

[Fedge]

The low pressure switch is in that area. On top of the accumulator. But you said you've already replaced that? Did you try jumping that switch?

Have you verified that there is enough refrigerant in the system?

covered the basics...jumped the LPS after I checked all of the fuses and swapped all of the relays

 

[Fedge]

Check Autozone's website for a schematic.

nuts, listed some stuff but not all (like almost all of the dash mounted stuff) no good for tracing down the AC related stuff

 

[TheJackal]

I don't think there is a thermal sensor in the system; if it does freeze up the pressure on the high side would build up and the high side pressure cutoff would kick in. I'll have to check this later to be sure, but I don't remember there being anything else.

If you're sure the system is holding good static pressure, try jumping the terminals at the harness for the low pressure switch, and again at the high pressure switch. If one of them turns the compressor on but not the other, there could be a problem for the wiring going to that switch.

 

[Fedge]

I don't think there is a thermal sensor in the system; if it does freeze up the pressure on the high side would build up and the high side pressure cutoff would kick in. I'll have to check this later to be sure, but I don't remember there being anything else.

If you're sure the system is holding good static pressure, try jumping the terminals at the harness for the low pressure switch, and again at the high pressure switch. If one of them turns the compressor on but not the other, there could be a problem for the wiring going to that switch.

I'm thinking the wiring as well...i will recheck the system pressure and try to get some numbers with the compressor jumped and running

man I love forums, lol thanks for the info

 

[Fedge]

Issue solved...it turn out to be a wiring issue. I had a bad ground, just tapped in a new one at the plug and all is right with the world. Thanks for all the replies and suggestions!

 

[BrooklynBay]

Thanks for the update!

 

[Fedge]

no problem, hopefully it'll help others chase down a similar issue!