1981 Rear window defogger

[Nobody Cares]

Trying to trace the problem with the rear window defogger on the 81. Sometimes it will work (not very often ). Is there a breaker to check and where is the breaker located ?? Just one of those things that bugs me not working. Dave

 

[bill81vette]

Dave,I'll check on the breaker...but in the mean time check to make sure the ground is good,lots of times that is a problem with these vettes,due to age and corrosion I believe it is behind the overhead panels behind the t-tops..

 

[Nobody Cares]

I'll do a check on the ground Bill. If i am right there is a 30 or 35 amp circuit breaker some where , just not sure where .

Probably not for a few days though. Highs the next few days is only around 6 to 8 degrees and lows well below zero at night.

 

[Tom Bryant]

I had to replace the switch on ours several years ago but it failed completely. An intermittent problem may be harder to trace down. I'd start by checking all of the connections including the ground as mentioned above.

Tom

 

[Nobody Cares]

Ok Tom, will do . Thnx dave

 

[Yoda]

Dave,

The Circuit Breaker is located on the fuse panel, you can see it below, it is the CB 35 amp box

I agree with Bill & Tom connections, connections, connections also contact points of the switch it could be something as simple as the plug at the defog on connection at the window film

Bud

 

[Nobody Cares]

Thanks for the fuse panel diagram Bud. I'll checks things out first chance i get (connections ) Dave

 

[jdp6000]

If its like the 82 there is also a relay.

Jim

 

[Nobody Cares]

Any idea Jim where the relay is ?? Thnx Dave

 

[bill81vette]

I don't know if there is a relay for it unless it's in the switch....

 

[jdp6000]

My mistake. No relay. Just a connector in the rear left quarter panel.

Diagram shows 30 amp fuse for the defrost on circuit with orange and black wire. Guage fuse also has something to do with it on the pink/black wire. Coming out of the switch is a black to ground. a purple that goes to the connector in the rear left quarter and switches to a black which terminates at the grid.

Check your grid lines on the window a worn one could cause a problem.

Jim

 

[Nobody Cares]

Ok Jim , Thanks for the info . Dave

 

[jdp6000]

Just looked in a spare I have. There is a built in delay. Maybe the contacts are bent out of place on yours. You may have to open it up and try to fix it.

Jim

 

[Nobody Cares]

Thnx again Jim. I'll check it out. I really haven't done much outside in the garage lately, been way too COLD. Dave

 

[Vette79]

Please keep me posted as well seeings how I am having the same exact problem...Thanks.

 

[jdp6000]

Found this for a 78. A bit different...suggests the timer is separate...

 

[duke94]

Check this thread for same issue on a 79'
http://www.corvetteactioncenter.com/forums/showthread.php?t=93314

 

[Nobody Cares]

Sure will. Should be able to get the car out this weekend and take a look. Dave

 

[Vette79]

I am going to do this as well. Hope mine is as simple as a connection.

 

[Nobody Cares]

Hope it is that simple. Just one of those things that bugs me if it's not working. Dave