96 grand voyager air conditioning/cooling fan question.

[proserver]

Hi all,

I posted about a week ago concerning my AC on my 96 grand voyager with a 3.0. Basically I wasn't getting any cold air so I charged it. It showed that I overcharged it so I bled it back off to correct level on the gauge. I did this with the ac on full, all vents open, and at the coldest setting. I still couldn't get any cold air.

I didn't get any responses so I went back and checked some more and I found the following:

The clutch engages and the compressor turns. You can here the "click" and you can detect the load of the compressor being put on the engine.The line coming out of the top of the compressor is hot, the bottom line is "warm". When looking at all of this I realized the cooling fans never kick on. I unplugged the fan closest to the battery and jumped the fan motor straight to the battery and didn't get anything. I also pulled the fan relay and it didn't look or smell burnt. I have no codes and all fuses are OK.

Can the a/c and cooling fan problem be related?

Thanks .

[jpb53]

This will tell you how the fan operates and what the A/C pressure transducer does.
http://www.automotiveforums.com/vbul...ure+transducer. An A/C system removes heat and moisture from the air it does not make cold air.

[Spit]

Lot's of questions.... when you jumped the fan did you jump both the 12volt and to a good ground? If you did and the fan didn't run... the fan is bad.

Are you using a set of AC pressure guages to see what's going on?
Figuring out what's happening in a sealed refrigeration system is a lot like trying to figure out what's happening in an electrical circuit...you can't see electricity nor can you see what a compressor is or isn't doing. That's why we need/use volt-ohm meters on electric circuits and guage sets on AC.

I assume that you aren't using guages...The high side and low side pressure readings really let you see what's happening when the compressor runs. You can get a set of guages and hoses at Harbor Freight for less than $50. Not a bad investment for a owner of this age/series of Chrysler Mini-vans. I know that I've given mine a work out on my 97 GC .. Haynes publishes a Heating and cooling repair manual that has all the specs...high & low pressures, gas charge, oil charge etc. There are also some very good trouble-shooting guides...based on what the gauges show.

There is a thermostatic expansion valve mounted to the firewall that controls the amount of gas that enters the evaporator. If this valve goes bad it can prevent proper cooling

My 97 Grand Caravan has a solid state fan relay mounted down below the battery close to the radiator that went bad once.

Spit

[proserver]

OK heres what happened. I took the fan relay out to check it out and put it back in. Now the fan works and the AC is working???? The only thing I can think of is the conductive grease on the back of the relay was solidified and the screws were rusty. In other words, a bad ground??

Thanks for the insight on checking things out. If it weren't for people like you taking the time to help out, I would have never even known about the fan relay.

[jpb53]

The black wire in the fan relay connector is the ground for the relay. It is bolted to the frame to dissipate heat.