Will do that first thing tomorrow. Looks like fun getting to it.

I'll will post up what I find.

Thanks again. This is very helpful.

i probably wont be able to check in tomorrow but i hope you find it.

If the compressor restarts after sitting (engine idling), my money'* on a borderline low charge.

When you're driving, the condenser press/temp drops, tripping the low press switch.

I agree with JWfirebird, check the voltage to the a/c clutch when it stops, I bet you'll find 0 volts.

When the **** is on "MAX", you're running recirc air, causing the pressures to drop even more (it'* cooler in your truck than outside)

luck,greg

I can't edit yet

You might pull the plug while the compresser has failed, check both terms to ground.


luck,greg

Damn. I saw this all after I messed with it today. I had the passenger front wheel off and the switch was pretty easy to get to through the wheel well.

I could not get the A/C to stop blowing cold. Now I know why. I was working on the brakes while I was letting the A/C blow.... With the windows down. Whoops.

When I check the switch it had 12, of course.

So, should I just put a little charge in it and see what happens. I have some coolant.

Back in the early 70'* I was a Mercedes tech, when we did a/c, we had a large 24" fan in front of the rad (simulating 30mph), all windows down, a/c blower on med.
just fyi

My sonoma wasn't working, I did a similiar setup, put in a half a can and when the a/c clutch pulled in, I shot the rest of the can in. (upright & shakin')

It blew the valves in the compressor, so I'd only put in enough to bring on the compressor and stop.

If that doesn't resolve it, read more or take it in to a shop, I don't know the test pressures for your truck (if you're using numerical gauges)

luck,greg

Thanks a lot for the input guys.

I just put the gauges back on.

43 on the low
190 high

How high should I take the pressure on the low?

Sorry, can't edit either.

I'll try to look for a service manual to check low side pressure numbers.

If you were running on "MAX" (recirculated air) for long enough to de-humidify & cool down the interior AND had a fan blowing air across the condensor (assuming 75ish outside temp) - I'd leave it there.

The low (suction) pressure is close to the evap coil press (inside the truck)
The air across the coil will run 10deg warmer than the press (in general)
That should put you @ about 55ish disch air temp out of vents
Understand the press & temp is going to drop as the interior cools down, that'* why we don't test on "max" - since the readings will change.

But I think the 43 suction as bad, if there'* a decent load on it.
The 190 high is dependent on airflow & air temp across the cond coil (and cleanliness of coil)

luck,greg

I hate this no-edit

I meant to say the 43# suction is NOT bad, if there'* a load on it

Depends on load, blower speed, etc.

luck,greg