Blown ERLS fuse when using AC or Defroster

TOMFRU

MEMBER
CADILLAC DEVILLE

I have a 1992 Cadillac Deville with 116,000 miles. I have been to 2 mechanics who have yet to be able to figure out my problem but it would appear to be an elctrical short somewhere. If I choose either the Auto or Defroster (not the rear window defogger) buttons the The Airconditioning does not function and the car starts from a stop as if it is in 2nd or 3 rd gear. So far as far as the mechanics have gotten is that the 15 Amp ERLS fuse blows and causes these symptoms. I can replace the fuse and drive it fine as long as I do not use the AC or Defroster. For now I am just sweating in the 90+ temps that we are currently having but being in the Northeast my big concern is that I will have no Defroster I the Winter (or even on humid days wih lots of rain during the summer that makes having the windows wide open not the best idea. I was thinking of replacing the Electronic Climate control unit in the dash but before I bought it tried to ask a Mechanic at another sight. He feels I am way off base in trying this, but has yet to come up with any suggestions. Any thoughts?

Friday, July 14th, 2006 AT 10:37 AM

4 Replies

DENVER16

MEMBER
2 POSTS

I also have the problem of the ERLS fuse blowing when using the AC. The AC clutch tests as NOT shorted. Did Tomfru resolve his problem?

This fuse also is for the Cruise Control, EGR, Transmision shifting, and power steering pressure sensor.

I had it at a transmission shop, and a mechanic (twice each). Both could not resolve the fuse blowing problem.

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Tuesday, May 8th, 2007 AT 9:12 AM

TOMFRU

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3 POSTS

I had wound up troubleshooting the problem to a shorted AC clutch and repalced it, but it fried again with 2 months. I have basically been living with the problem and as long as I keep the 2 wire connector going to the coil unplugged the fuse does not blow, but it seems obvious that something else in the circuit is actually the real culprit and caused the AC clutch to burn out. Now that it will be Summer soon here I am coincidentally bringing it back to the shop tomorrow to try and have them troubleshoot the problem further. I will post if they have any success.

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Tuesday, May 8th, 2007 AT 10:24 AM

DENVER16

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2 POSTS

Recently had the A/C Relay replaced and feeding the power to the relay from anouther source. Neither worked. Tomorrow they want to replace the A/C clutch. This is supose to cost about $300 on top of the $300 I have paid preveously to diagnose this problem. Let me know if anything else could blow this circuit.

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Monday, May 21st, 2007 AT 2:30 PM

TOMFRU

MEMBER
3 POSTS

I had come across someone on another forum who said their problem wound up being a harness issue and I now beleieve mine is as well. I had the car back to my mechanic for a couble of days and he could not pin point the source of the problem. I stopped on my way home from work and tried a couple of things together but the fuse still popped. He reached down follwoing the harness with his hands as it went down near the alternator and also the harness that goes down to the transmission (for the VISCOVS circuit) and said maybe I had better try an Electrical Shop to see if they had more advanced equipment to troubleshoot the problem. I decdied I would go buy a mega pack of 15 Amp fuses and try some more isolation myself before going to a genereally very expensive Auto Electric shop. The fuse has not popped again and I can use the AC and Defroster with no problem. To me the only variable is that one of the harness has some cut insulation that was contacting metal and when he was feeling around he moved it enough so that is no longer shorting. I am not touching a thing unless the fuse goes again.

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Monday, May 21st, 2007 AT 2:49 PM