A/C issue (all switches are ok)

[2 Dr 2 the North]

The compressor doesn't come on and so I get no cold from the A/C.

My friend put the gauges on: NO leaks and pressure/freon was all good too.

ALL pressure switches checked and were good.

Ground on thermostat housing was broken - replaced that and still nothing.

We did check all the fuses - all good.

We traced it to the A/C relay - when we pulled the relay and jumped the port - the compressor came on finally. An electrician checked the relay by putting power to it and it was fine (click -click).

So - my friend says that there is NO power going to the switch/relay.

Where do I go from here guys??? Dash switch, ECM ??

Thanks

 

[994door]

i say replace the relay if you remove the relay and jumped it and it started the compressor then the power is good

 

[96ProCompTahoe]

may want to check the heater control switch, they can go bad, would be the next thing i'd check if you are absolutely sure its not the relay.

 

[2 Dr 2 the North]

Thanks for the reply guys.

I had pulled the relay and hooked it up to 12v on the prongs and it was clicking (opening/closing).....so I think its good?

The A/C button lights up when pushed in.... (and the heater control/fan switch comes on too.....I will have to take them off to test though.

 

[994door]

what method did you use to jump the relay, also how did you test the pressure switches. If you unplug the switch at the accumulator and jump the plug with a wire or paperclip with the a/c on high does the compressor start?

 

[2 Dr 2 the North]

When we jumped it with the A/C relay out - my pal stuck 2 pieces of metal in the receptacle area - the compressor came on and was fine. (My electrician friend at work helped me jump the relay with batteries - and it clicked on/off - AS LONG AS WE TOUCH THE RIGHT PRONGS???)

We jumped all the switches with a small piece of wire at the accumulator and the 2 on the compressor - and no go for them all. And the volt meter did show they were all getting the 12v I believe. (my friend was doing this and giving commentary while I was inside the cab).

He says - its not getting the 12v TO THE A/C RELAY for it to close and let the power get through....

 

[994door]

that is why i am saying its the relay if you jumped the receptacle that means it has power so it can only be the relay it you have a buddy with a similar truck try his

 

[2 Dr 2 the North]

Ok - I understand now...will try a newer relay when I have a moment.

Thanks

 

[2 Dr 2 the North]

Does it matter which way this A/C relay goes in/face?