Rear Defroster INOP
Thread Starter
Melting Slicks
Joined: Feb 2005
Posts: 3,467
Likes: 43
From: Auburn MA
Rear Defroster INOP
I have a 94 coupe and my rear defroster isnt working. The light comes on on the Climate control unit saying its on I can see the side mirrors defogging but the rear window doesnt appear to be defogging. I have checked to see if they are connected but everything seems to be fine. I dont understand whats going on. What should I be looking for to fix this.
Thread Starter
Melting Slicks
Joined: Feb 2005
Posts: 3,467
Likes: 43
From: Auburn MA
Team Owner
Joined: Jan 2003
Posts: 20,315
Likes: 245
From: Summerland B.C. Canada
Put a lead on each strut connector. Should show 12 volts if power and ground are present. If it doesn't, then your missing ground or power at the struts. On my 86, right hand strut is hot, left strut is ground.
You can isolate which terminal is the problem by putting one lead on a known good ground and the other to hot strut, and putting one lead on a known 12 volt supply and the other lead to ground strut.
You can isolate which terminal is the problem by putting one lead on a known good ground and the other to hot strut, and putting one lead on a known 12 volt supply and the other lead to ground strut.
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
The 4 push on connectors can get corroded and cause a bad connection. I had this trouble with my 94 also. I had voltage at the lower connectors but not the upper ones where they connect near the wires. I had to remove the corrosion and clean them up. I also found out that even with the ignition on, no voltage will be present at the connectors. I had to run the engine to get voltage to the connectors.
I believe this is a sort of safeguard by the CCM that only enables power when engine is running, as the alternator to. Big current draw on battery if alternator is not running.
I believe this is a sort of safeguard by the CCM that only enables power when engine is running, as the alternator to. Big current draw on battery if alternator is not running.
Thread Starter
Melting Slicks
Joined: Feb 2005
Posts: 3,467
Likes: 43
From: Auburn MA
The 4 push on connectors can get corroded and cause a bad connection. I had this trouble with my 94 also. I had voltage at the lower connectors but not the upper ones where they connect near the wires. I had to remove the corrosion and clean them up. I also found out that even with the ignition on, no voltage will be present at the connectors. I had to run the engine to get voltage to the connectors.
I believe this is a sort of safeguard by the CCM that only enables power when engine is running, as the alternator to. Big current draw on battery if alternator is not running.
I believe this is a sort of safeguard by the CCM that only enables power when engine is running, as the alternator to. Big current draw on battery if alternator is not running.
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
That’s a pretty open question. Some will say contact cleaner to start off with. In my case one pin was so bad I had to use some light emery cloth (or light sand paper) to get it where it started to shin again. Even scraping did not do it. Then I slightly tightened the female part because it was to loose. I has a very high build up of white crud. I checked all for tightness also. Be careful, don’t get to aggressive on the terminals or they could break. Go easy, remove things slowly and gently or you will hate yourself. If there is a bad contact, its usually just one the culprit. 
