ac compressor troubleshoot

[primordialpaul]

So im trying to get my ac going. From the start of troubleshooting i manually spun the compressor to make sure it wasnt locked up, learned the system has a low pressure auto cutoff, added uv die and stop leak and recharged the system to where i believe it should run on its own, at that point i still had no action. With the recharge and a jumper wire from the battery to the plug on top of the compressor makes it run no problem and blows cold, from here im not sure where to go as it continues to show no power at the plug. At this point im looking at running a a switch with an inline fuse straight from the battery but if possible would like to avoid it. This truck is a nightmare i really dont care about the longevity i bought it for a one time trip from new england to n carolina and ive had it nearly a year now with few real issues but i deliver pizza and its too damn hot and humid to be driving all day without ac. Tyia. Paul.

 

[SoHK_alumni]

Hmmm, probably only 4 or 5 things to check since it blows cold when jumpered.

Relay, a/c switch or auto climate control, a/c low pressure switch, a/c high pressure switch, WOT relay in the PCM.

Relay, low and high switches are most common.

The AETC is a known pita.

WOT is least likely.

High and low switches can be jumped easily, relay can be swapped with similar from relay box. The relay socket is a handy place to check if dash contol is trying to turn on a/c.

 

[MAS Tequila]

Overcharging is very easy to do, especially without a real set of manifold gauges, hell I overcharged mine yesterday with the gauges, if overcharged it won't get the signal to run.

Also, please check the fuse under the hood.

Don't ask how much time I lost trying to find the problem with mine, when in the end it was a lousy 10 amp little fuse.

But after installing a new compressor, condenser, drier, o-tube, and hoses, it had to be something simple.

Good Luck

 

[bobflood]

Need to do some electrical troubleshooting. Best place to start is the low pressure switch, as it is first thing after the relay. Unplug connector and look for power on one of the leads in the socket - use a test light, not a meter. If you have power there, your console control and relay are both good. If not, one of them is bad. Follow the circuit in the indicated direction until you 1) lose power if you are moving toward the compressor 2) find poser if you are moving toward the console. Good luck.

 

[primordialpaul]

So i got up early where i had left off and tackled most of the testing you guys mentioned here, i ealized that orange plastic fitting was the low pressure switch and i had no power there, i already had checked relays and fuses, always first step sorry i hadnt mentioned i forget common sense isnt so common these days haha.. all relays and fuses are good. Also when jumped at the low pressure switch it runs cold. I know those gauges on the refill kit arent great but if anything i might be on the low side or in range, but i found out about the sensor in the glove compartment, and that seems to be my issue im not sure how to go about testing it but process of elimination points that way. Unless i missed something.

 

[bobflood]

Do you have manual controls (dials) or the EATC (where you just set the temperature you want)?

 

[primordialpaul]

Manual controls. I had wired a switch from battery to compressor and now im having power issues while its running so i guess thats out.. im starting to loathe this truck..