Rear defrost/door lock breaker blowing... - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Everything Electrical & Electronic Have an electrical problem? Lighting, Alternators, gauges, DIC, HUD, etc? Post it here. Please post Audio problems in the Audio forum, and Engine control problems in the appropriate Mechanical forum for your year.

Reply
 
 
 
Thread Tools Search this Thread
Old 12-15-2007, 12:42 PM   #1
Senior Member
Posts like a Supercharger
Thread Starter
 
Join Date: Jan 2006
Location: Edmonton, Alberta, Canada
Posts: 176
Thanks: 0
Thanked 0 Times in 0 Posts
Cyric78 is on a distinguished road
Default Rear defrost/door lock breaker blowing...

Hey all... I've got a pretty bad problem here (atleast in my opinion, here in Canada..).. When I turn on my rear defrost, it pops the 30A breaker in the drivers side fuse block... and I need the rear defrost to work, since its cold out, and if I don't let the car run for 5-10 mins before I go out, my windows will fog up... Any ideas where the short might be? The breaker gets really hot when it trips..... so I know its a power grounding out.. but where..

And one more thing... the engine in this car didn't have any coolant in it when I got it, and yes, she was overheated enough to turn the metal on the spark plugs blue, which have been replaced, but now, I get a low coolant light come on all the time... I'm assuming that there is an air bubble in the system somewhere, but how do I get it out, or is it the coolant level sensor that is flakey?
Cyric78 is offline   Reply With Quote
Old 12-15-2007, 01:13 PM   #2
Junior Member
Posts like a Ricer Type-R
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

On your rear defrost:

You have a short to ground or a weak breaker. Are you running metallized tint on the rear window that could be shorting the grid? Anything on the rear deck that'* touching two lines? Any damage to the wiring harness?

On the low coolant light, check your radiator level. That'* all that matters. The sensor is on the back side of the radiator near the top. If the radiator is full, remove the sensor and clean the face of the sensor if it'* gunked up. If not, either replace the sensor or simply unplug it.


I'll move your topic to Electrical. Both problems seem to be going in that direction.
willwren is offline   Reply With Quote
Old 12-15-2007, 02:01 PM   #3
Senior Member
Posts like a Supercharger
Thread Starter
 
Join Date: Jan 2006
Location: Edmonton, Alberta, Canada
Posts: 176
Thanks: 0
Thanked 0 Times in 0 Posts
Cyric78 is on a distinguished road
Default

As far as I know, the wiring is intact for the rear defrost, and no, there is no tint in the car yet, that is something I'm looking at doing next year.. I'm thinking that there is a bad ground somewhere or something.. I just don't know where the wiring runs for the defrost... is there any common problem areas that corrode that I can maybe clean up/repair?

I didn't know where the low coolant sensor is located on these cars, since I didn't have this problem on my 90, but good to know that it is on the rad.. I'll see if I can take a look at that today or tommorow...
Cyric78 is offline   Reply With Quote
Old 12-15-2007, 03:55 PM   #4
Junior Member
Posts like a Ricer Type-R
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

It cannot be a 'bad' ground. If it were, no current would flow in the circuit, and no fuse or breaker would pop.

It has to be a bad POWER wire, shorted to ground where it shouldn't. Power short to ground, that'* what you're looking for. Forget the ground side of the circuit entirely. OR a weak breaker. Don't rule that out.

Look at your radiator. On the back side of it near the top, you'll see the sensor. They're the only two wires actually going TO the radiator.
willwren is offline   Reply With Quote
Old 12-18-2007, 12:46 AM   #5
Senior Member
Posts like a 4 Banger
 
Join Date: Dec 2004
Location: Rochester, NY
Posts: 113
Thanks: 0
Thanked 0 Times in 0 Posts
ukie eagle is on a distinguished road
Default

Interesting - I too, am having issues with the Rear Window Defroster/Power Lock circuit now that winter is upon us... :(
When I turn on the Defroster, after a couple minutes it shuts off [way before it used to, & way before the window is clear] and then won't allow me to turn it back on. After this happens, the Power Locks don't work.
If I wait a while, the Power Locks work again.
ukie eagle is offline   Reply With Quote
Old 12-18-2007, 11:38 AM   #6
Senior Member
Posts like a Northstar
 
Join Date: Sep 2005
Location: Dayton, OH
Posts: 600
Thanks: 0
Thanked 0 Times in 0 Posts
imidazol is on a distinguished road
Default

Quote:
Originally Posted by ukie eagle
Interesting - I too, am having issues with the Rear Window Defroster/Power Lock circuit now that winter is upon us... :(
When I turn on the Defroster, after a couple minutes it shuts off [way before it used to, & way before the window is clear] and then won't allow me to turn it back on. After this happens, the Power Locks don't work.
If I wait a while, the Power Locks work again.
In your case it may be the ground buss by the front pillar under the door trim. I had a 93 where the door locks and the AC control would both quit for a period of minutes or until the next restart. I had decided it was the ground. Never took it out; my wife traded it for her new shiny one first. I never checked the rear defogger to see if it quit working at the time.
imidazol is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Rear Defrost + Door locks issue? BonneMeMN Everything Electrical & Electronic 9 01-20-2007 10:52 AM
2000 ssei, Door lock switch, LOCK works, UNLOCK does not caminated2k Everything Electrical & Electronic 14 11-27-2005 03:53 AM
Rear Defroster keep cause the breaker to trip Masterbm Everything Electrical & Electronic 9 09-22-2005 09:08 PM
rear defrost cuts out its840 Everything Electrical & Electronic 11 12-21-2004 01:54 AM
door lock will lock but not open Grease is the Word 1992-1999 4 08-30-2004 09:53 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 08:59 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.