96 A/C Problem

I am away on vacation and the A/C on my 96 has become intermitent.

At times the compressor clutch will not engage, when it does it cools fine till the next time it goes to cycle. I was going to jump the low pressure switch but just before I reached for it it came on. I had not touched anything yet so it was not me that made it run.

When you turn it on the ECM gives the idle a small bump (about 200rpm) but because the clutch did not engage it settles back down to 700 in a second. Also the radiator fans are runing on low the entire time, engine temp is normal so the ECM is not shuting it dow to prevent an overheat,

I am assuming the ECM controls a relay to power the clutch, anyone know the location and is it swapable with any other relays to test?? Any other ideas on what to look for?

Of course my service manual is at home, I do have a downloaded ISO for the truck but never burned it to CD, anyone know if it fits on a regular CD or does it need a DVD

Open all the doors and liftgate and turn the ac on full blast. Look down on the air gap on the compressor clutch ... there you can see if the clutch is engaged or not. A flashlight may help if you are in a dark area.

With the doors all open the ac system should never "catch up" ... the clutch should stay engaged. Likely you will see it is cycling ... in and out. 99 times out of a 100 this means low refrigerant.

Thanks 12oz

I already know the clutch is not engaging intermitently, refrigerant charge is good.

Just for kicks I jumped the low pressure cycling switch and the clutch engages, took it for a 15 min ride and it was frosty, so frosty the air flow started to reduce because the evaperator frosted up. The accumilator and fittings also had frost.

So it's off to the store to see if anyone has the switch in stock, if not I will wire a switch in the cabin to allow me to cycle the clutch. I have a 14 hour drive ahead of me and figgure I will have to cycle it about every 5 min to keep the evap frost free.

I did get my CD to work and it tells me that there is a schrader core behind the switch so I can remove it without dumping the refrigerant charge.

Replaced the switch and all is well.

I was driving down Main St in Anderson SC looking for an autoparts store. What do I find but a Ford dealer. It had to be the nicest ford parts and service dept I have ever been in.

The dealers in Long Island could learn something from Anderson Ford in SC