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AC problems

B

bucholzi

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My AC does not blow cold air, and there hasn't been warm enough before today to be absolutely sure. Today I tried to run it a bit at max to see what happened, after the truck had been sitting in the sun (hooray, today summer came :smile5:). And as I suspected it didn't make any difference if the AC was on or not. And suddenly it started to blow the fuse, and does it every time now. I have tried the AC before without the fuse going off, and I don't think I left it on especially longer than I have done earlier.

I don't know if there's enough refrigerant pressure, and it's still a couple of weeks until I can get it refilled (busy busy at the garages around here, 4 weeks of waiting). Is there anything I can check before I get the refrigerant filled? I'm going on vacation just a couple of days after, and it would be nice to rule out other stuff than refrigerant pressure, and anyway it can't be right that the fuse blows.
 
Sorted out the fuse, it was a non-related sort circuit. But still, anything I can check before I check/refill refrigerant? Probably not, but two days between refill and vacation doesn't leave much time to fix a possible bug..
 
Low refrigerant will not blow the fuse. If you are blowing the fuse you have a short. Typically when the magnet goes bad on the compressor clutch that can cause it and it's an easy place to start. Unplug the compressor and try a new fuse. If it doesn't blow , you need a clutch. if it blows, well you gotta start tracing wires until you find it which can be a real bitch. That's why I only do A/C on heavy equip and Class 8 Trucks. Much easier o work on. Good luck. Hopefully it's just a clutch.
 
The relay in the fuse box clicks, but the pump does not engage, or at least nothing happens that I can detect. All other pumps I have seen you could see the clutch engage, I reckon it's the same on this one.

Isn't there a sensor for the refrigerant, that one could check? Reckon it's just a switch that is open or close depending on the refrigerant being over or under a threshold pressure?
 
bucholzi said:
The relay in the fuse box clicks, but the pump does not engage, or at least nothing happens that I can detect. All other pumps I have seen you could see the clutch engage, I reckon it's the same on this one.

Isn't there a sensor for the refrigerant, that one could check? Reckon it's just a switch that is open or close depending on the refrigerant being over or under a threshold pressure?
Click to expand...

The relay engages whenever the A/C control head calls for the compressor. The low and high pressure switches actually switch the compressor off and on. Unplug the sensor at the accumulator(passenger side, has a big hose on the front and hooks to a big line that comes out of the firewall) and connect a jumper wire across it's 2 terminals and see if the compressor comes on. If it does your electrical circuit is fine. Also do not connect the jumper for long because if the system is low you can burn the compressor up due to no oil flow. If the compressor does come on then you need to check your charge, if it doesn't then you need to check your electrical.
 
The pressure sensor was open, and the pump started as soon as I jumped the wire. Guess it's the pressure then, so I'll just wait and see if a refill sorts it out. Thanks, all.
 
You can try to refill it a few times last me about 1.5 years. Sooner or later, just have to bite the bullet and fix it. I did it late last year. The compressor is probably bad. It is a 95 and now is 2009. Lasted 14 years, that is good.
 
bucholzi said:
The pressure sensor was open, and the pump started as soon as I jumped the wire. Guess it's the pressure then, so I'll just wait and see if a refill sorts it out. Thanks, all.
Click to expand...

The low pressure switches do fail on these, but you need to check your pressures to be certain unless you have another low pressure switch to try out on it. If the A/C just suddenly quit working there is a good chance it's the switch, if it slowly quit working then it is most likely charge is low.
 
Acesneights1 said:
Did someone put tracer dye in it ?
Click to expand...

Had a shop try to refill it, reckon its dye in the refrigerant. Didn't look like the oil itself was green, but it was hard to tell. They said that it held vacuum, but as soon as they started to fill it it started to leak. Leak is at the bottom corner on the passenger side, which looks like the part which is most exposed to the salt slush which the truck has been rolling in every winter :rolleyes5:
 
Oyyy. I hate that stuff. Most shops don't know how to use it properly. I prefer not to use it at all unless I can't find it any other way. You may want to consider flushing the system and changing the Oil in the compressor as well as a new dryer. Probably overkill but I really don't like that stuff and not know how much(probably too much) they put in it's not good. JMHO I'm sure some will swear by the stuff.
 
I didn't know if or where I had a leak, just that the AC didn't work, so in this case it worked out well. Can tell them to go easy on the stuff at the next attempt, after I have replaced the condenser.
 
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