Smokindog

I had the compressor on my 1997 Z71 replaced a few years ago. After that replacement the A/C would only come on intermittently and after the truck warmed up. I took it back and the dealer said one of the connectors had been cracked and was only making a solid connection after it heated up. They said they replaced it and all was well for a few years. It only took about 15 minutes to affect the repair while I waited so it must be a fairly accessible electrical connector. He described it as the pin getting pushed out the other end when reconnecting. UNFORTUNATELY, I didn't make the dealer show me which connector.

I recently had a new water pump installed and now the A/C is doing the same thing, typically coming on after I drive, park, and then go on to the next location.

I tried to follow the wires from the clutch (my guess from the dealer description years ago) but am having no luck.

Can anyone help point me to which connector may have the failure? I suspect the original repair was not a replace but maybe a jiggle and tape job that got disturbed when the water pump work was done.

Barry A. Waters

Smokindog,

If your 1997 is anything like my 1995 C1500 I would first look at three connections: 1) The Low Pressure Cut-Out Switch - this should connect to the Accumulator/Dryer on the Right-Side Engine Firewall (it's a cylindrical Aluminum vessel with black foam insulation on the top and bottom of the cylinder and is easily accessible). I have had this fail before due to faulty contacts and the compressor will indeed not run. Check this first as it may be your issue. In my case I could remove the connector and jumper its two Female contacts (on the removed connector itself, NOT the Male pins on the Accumulator switch fitting) to make things work (engine running & AC on). If your compressor clutch engages then you may very well have found your problem. This is NOT a solution but just a diagnostic check so don't just jumper it and leave it like that - the compressor needs to cycle on/off regularly and this is the switch that primarily controls that function. 2) The 2nd connection would be the one on the Compressor itself that provides power/ground to the compressor's clutch coil. Again, this connection is very accessible - make sure you have good connectivity there. 3) The last would be the High Pressure Cut-Out Switch which may be either on the AC High Pressure Hose connection to the compressor itself OR hidden on the AC Condenser and just visible through the front of the truck's grille on the lower right-hand side. I think your best bet is to take a good look at the Low Pressure Switch on the Accumulator/Dryer and do the jumper test (on the removed connector and NOT the male pins on the Accumulator/Dryer itself) with the engine running and the AC switches engaged.

Oh, by the way, GREAT history/description of the issue! It REALLY helps folks help you. Good on ya Mate!

Barry

Smokindog

Thanks Barry,

I want to make sure I was clear about one point. The A/C works wonderfully once it engages. It's as though some metal in a power connector needs to sufficiently heat and expand to make a solid contact. Once that happens the air is cold and strong and consistent until the engine cools! That means my trip TO the store is usually uncomfortable but once I come out of the store and resume my trip I've got A/C. Pretty predictable that way!!!!!

That's why I made sure to include the original diagnosis of a connector that was cracked allowing a pin to get pushed out when reconnected. I suspect when they replaced the water pump they had to disconnect this same connector while removing things and when they put everything back together the pin again was partially pushed out of position. I need help locating the connectors in the electrical path to the clutch. Pictures would be awesome as the wires go into the combination wire wrap bundles and I'm having difficulties tracing what I need.

I'll take what you've given me out to the garage in the AM and see what I find!

THANKS AGAIN!