a little ac help please

diesel dane · Jun 23, 2014

A little ac help. ok guys. I'm almost wrapped up with the 97OBS. running great. but recently the ac stopped working. We aren't getting 12 v to the compressor and we checked all the fittings under the hood to track down maybe a short with the volt meter. No luck. Im thinking the problem is the AC switch in the cab. maybe something happened during the painting of all interior black.

Does anyone have a wiring diagram for the ac controls in the cab to diagnose if it is the switch or not? We can get the clutch on the compressor to move with a jumper from the battery so we can rule that out. it still blows hard. Just not cold.

Thanks in advance. :fordoval:

zilla68 · Jun 23, 2014

did you gut the dash to paint it all?
sounds like the door is stuck to me

diesel dane · Jun 23, 2014

took entire dash apart for paint. What door? Im thinking an electrical issue.

zilla68 · Jun 23, 2014

did all your plugs get put back on right on the back of the controls?
sorry, I misread you said no power to compressor, I was thinking if its blowing hard and not coming out maybe the blend door was stuck.

fuses and relays good?
I can look at home, I might have the info in my book I ordered online.

diesel dane · Jun 24, 2014

All plugs are in. I want to check voltage at the switch so I can determine if it's that or a short down stream. Anyone with a wiring diagram for Ac switch?

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Jake · Jun 24, 2014

I don't have the wiring diagram, but it basically goes from the dash switch, through the low pressure switch, then high pressure switch, then to the clutch.

Try jumpering out each of the switches to see if that does it. The high pressure switch have given me crap on every truck I've owned.

Philips97 · Jun 24, 2014

Sounds like you might be low on refrigerant if you jump it out, but blows warm air. Low pressure switch is probably keeping the compressor from coming on and tearing it up.

diesel dane · Jun 24, 2014

Philips97 said:
Sounds like you might be low on refrigerant if you jump it out, but blows warm air. Low pressure switch is probably keeping the compressor from coming on and tearing it up.

Now we're thinking. It's a possibility. The truck sat for a few years during the build. It didn't get charged as far as I know. That said, It was ice cold and then nothing leading me to think electrical. Luckily the truck pretty much only gets driven fast in the evening when the temps outside aren't scorching

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zilla68 · Jun 25, 2014

oh hell, I thought you already had put gauges on it, yes put gauges on it and see what your pressures are, if it's low, it won't even call for it to kick in.