2nd Gen Non-Engine/Transmission A\C Not Working...

[klaybus]

I've got a problem with my A\C & hoping to get some ideas. Last fall my A\C was working fine. Now the fan blows but no cold air. I don't even hear the compressor spinning up. I checked the one & only fuse I see in the panel & it's fine. Wouldn't my voltage gage show a drop when the A\C cycles like with the grid heaters?Anyone have any ideas?



TIA,

Clay

 

[illflem]

There's also a relay for the A/C under the hood in the fuse box, trade it for an adjacent one and see what happens. Most A/C problems stem from low refrigerant, doesn't have to be very low to blow no cold.

 

[klaybus]

AC

Bill,

If refrigerant was too low to blow cold, would that prevent the compressor clutches from engaging (trying to operate?)



Clay

 

[klaybus]

AC Update

I took an allen wrench & pushed in the ball valve & she blew pressure. I'm assuming that I don't have a leak due to the fact I still have pressure in the lines..... Correct? I'll try an adjacent block in the fuse box & then try adding some 134 I guess.



Clay



PS Does low refrigerant make the compressor not clutch up?



Clay

 

[Jim S]

I have the same problem. It started last spring. The A/C was ok in the fall but blew hot in the spring. One can of coolant fixed the problem it worked all summer. This spring I have the same problem. I am hoping another can of coolant will fix it for another summer. My truck is out of warranty so I'm not going to pay to have it serviced.

Jim

 

[PHX ATC]

Check the 134 level.



That just recently happened to mine, under warranty, and the dealer fixed it... it was some "flap" that wasn't allowing cold air to make it out to the vents, just the warm air. I don't know what the heck he was talking about, but it worked!

 

[Berrigan]

Yes low refrigerant charge will stop the clutch from engaging.



Look near your air filter at the lines comming out of the fire wall. The suction line will have a low pressure switch on it. Unplug the connector and jump the 2 wires together at the connector. If the clutch engages you either have a low charge or a bad pressure switch.



The switch is an easy fix. About 30 bucks at the dealer for parts. It just unscrews and has a schrader valve under it so you wont loos the charge. Dont forget the little o-ring.



If you dont have a manifold gage set it will be harder to detrmine the charge level. With the compressor running the suction line should be cool to cold. If its not your probably low on charge but its hard to be accurate when charging with out gages. PS dont overcharge it. hope this helps... ... ... Bill

 

[klaybus]

AC

I found a switch on the Low Pressure line coming out of the firewall & it seems to go into a bottle of sorts & then out of the bottle up to the compressor. I jumper the connector & the compressor at the engine still didn't come on. I also checked the 10 amp fuse & switched the AC clutch relay with another as Bill Fleming suggested & still nothing.

Any other suggestions?



TIA,

Clay

 

[LeeMac]

klaybus

my A/C had a leak so bad at the end of last August that the compressor would only run about 8hrs. with stop leak 134a. Two weeks ago I fixed the leak the system still had pressure. After charging the system I found that the relay in the fuse box under the hood was bad, by swapping it with the trailer relay. The relays are 1inch black square box with white writing, not a fuse. Hope this helps.

 

[Berrigan]

With all you have done and no fix you gotta do it the old fashon way. Get a dc volt meter. Pull the ac on off rotary switch in the dash. put one lead of meter to a good ground and the other on the power in lead of switch. follow through switch out under hood through low press switch and so forth till you get to the clutch. The connector on the clutch must have 12 v to work and the compressor must be grounded. good luck

 

[illflem]

I'm not sure if by having some one turn the A/C on without the engine running but key on if you might be able to hear the relay click. That will at least indicate which direction the problem lies, towards the dash or towards the compressor. If it only engages with the engine running you might have to break out the stethoscope or voltmeter.

 

[klaybus]

A\C

OK...

I've tried swapping out the relays, checked 10 amp fuse, checked relay on A\C with key in on position & heard A\C relay click as Bill suggested. Tried adding refrigerant but without the compressor running it would take none. (1) can of wasted refrigerant... . Checked for power at the compressor at the plug & could find none. I tried a dummy test light & got nothing,then tried a volt meter & got more of the same... . Nothing. Apparently with the relay clicking I'm assuming that the switch is working but apparently the power is getting lost between the relay & the compressor??

And so the story goes... . Any more suggestions? Just want to thank everyone for their input... .



Clay

:{ :{

 

[illflem]

Even though the relay clicks it still might not be passing power but I highly doubt this since you traded relays. Consider yourself lucky that the problem doesn't lie towards the dash, more of a hassle to get at. Think you know the drill from here on, follow the comp wire from the relay to see where you lose power. Concentrate on connections but don't discount the fact that the wire could be broken under it's insulation, it happens.

 

[klaybus]

AC

Yep,

Thats what I was thinking. Theres also a AC coil I was going to look into... . If all else fails I'll give my extended warranty a try! I just hate giving them the $100 deductible for something simple.

Thanks for the help Bill.



Clay

 

[DBCooper]

I didn't see any mention of the high pressure switch, maybe look at that? I am by no means knowlegable about this stuff so I may be way off. The switch is located on the high side just off the compressor (at least on a 98)

 

[MCSloan]

Have you checked the compressor clutch? The link plates in the clutch plate brake and it won't turn the compressor. Problem is you can't buy just the plate . Have to buy the whole clutch assembly for over $200. 00

 

[illflem]

Since he isn't getting power at the compressor the problem has to be electrical.