Bypassing AC compressor

[DeanMoriarty]

I think my AC compressor has seized, or is in the process of. Turning on the defrost kills the truck at a stop, or causes stalling / power loss when driving. Anyway... I think I'll just bypass it... anything special I need to do besides putting on a shorter belt? Should I actually remove the thing, pull fuses, unplug anything, etc?

 

[Bob Ayers]

Jusy unplug the wire going to the AC compressor clutch, tape it up, and secure it so it doesn't get into a pulley or belt.

 

[MAKG]

It might be seized.

Just unplug it. No need to do anything else. Then try to turn the hub by hand to see if it really is binding, or if your problem is actually an electrical drain coupled with a poor charging system.

Note that your engine should have little trouble turning the engine anyway, with a completely seized compressor. It should smoke the serpentine belt while doing this, and the smell is unmistakeable.

 

[DeanMoriarty]

I like that idea better... since I just replaced the belt a few months ago. Thanks.

I'm pretty sure it's the compressor. I had someone else switch the defrost on while I was under the hood... It let out a God-awful screeching noise and puffed out a little smoke or rust or something just before killing the truck. My AC had gone out over the summer... but it wasn't doing this... it just didn't blow cold. I'd assumed it just needed a recharge.

I didn't notice a smell... but it killed it almost immediately. I'm going to check it out again and see what I find.

 

[DeanMoriarty]

I unplugged it and it seems to run fine now. The hub is totally seized, I couldn't get it to move a bit.
You think I may have another problem?

 

[Bob Ayers]

Well, when the compessor dies, it will usually contaminate the system with debris. You will need to replace the receiver/drier, orifice tube, and flush the condenser out very well!

 

[DeanMoriarty]

Maybe this is a stupid question, but here goes;
If I decide not to replace the compressor and just do without AC, do I still need to do these things? The truck is 15 years old and I'm really not wanting to put more $$$ into unless necessary.

 

[Bob Ayers]

Maybe this is a stupid question, but here goes;
If I decide not to replace the compressor and just do without AC, do I still need to do these things? The truck is 15 years old and I'm really not wanting to put more $$$ into unless necessary.

No, the things I mentioned only has to be done if you decide to replace the compressor to get the AC working again.

 

[DeanMoriarty]

Very good.. that's what I assumed but I'd rather be certain.

Thanks for the help everyone.

 

[MAKG]

No, if you're going to let the air conditioner die, just leave it as it is.

Though I never understood how folks could stand that. Even in a cool climate, the defogger works a whole heck of a lot better with A/C.

The worst case is that you need all-new refrigerant systems. It's about $600 in parts, brand new. More like $200 from a good junkyard (not Pick'n'Pull). But it is possible for the compressor to seize without blowing chunks everywhere. Your orifice tube will tell.

It might have been just low on refrigerant once upon a time, but it's obviously more than that now. Loss of refrigerant involves loss of lubricant as well.

 

[AllanD]

BTW, to "disable" the AC system it's generally easier to either disconnect the connector from the Dual function low pressure switch on the receiver drier OR simply pull the A/C-WOT relay out of the relay panel under the hood.

Because the wire you diosconnect from the compressor clutch can "dangle"
and get into trouble.

As for having A/C? I use it just as much in the "off-season" as I do in the summer.

because it makes the defroster FAR more effective without baking my sinuses
into total wreckage.

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