rear window defroster question

[michi]

So my rear defroster somethimes works and somethimes not... its pretty annoying when it does not work, especially in winter.
The switch seems to be okay, it also lights up and goes off when i turn the switch off. But like i said, it "mostly" dont work when i turn it on...
Anyone can tell me where i have to search first to fix it?

[wicked-irocz]

Make sure theres power at the back window.

[michi]

There is power but i think i should look how long i have power there cause somethimes it works and then it just stops working... but the switch still says its ON. When i turn it off and turn it on again it still wont work...

[weba]

It's useless from the factory, been like that on all 4 Beretta's I've owned. It has a circuit breaker that turns the defroster off after couple minutes of usage so it would not heat too much.

Switch will stay on, it will take quite a long time for the circuit breaker to reset it self and the defroster start working..
Also as long the circuit break is 'activated', power locks don't work, they are in the same wiring. At least on my cars it was.

[michi]

Oh and i always wonder why my power locks somethimes just wont work since this winter! ROFL

on my gtz that switch works just fine and also turns off after some minutes... and the rear window is nice too lock outside again... even when it was all frozen the winter i drove when i got her.
On my gt the switch does not turn off automaticly (wondered me for the first time)... it just stops working and does not start again...

[3X00-Modified]

Replace the circuit breaker for the defroster and locks. I had this problem with locks and defroser and after replacing that relay in the fuse pannel it worked as it should and the switch controlled when the defroster would shut off.

[michi]

Okay, i will check this tomorrow and lets see if i can get a replacement for that relay

[Cliff8928]

Replace the circuit breaker for the defroster and locks. I had this problem with locks and defroser and after replacing that relay in the fuse pannel it worked as it should and the switch controlled when the defroster would shut off.

Yeah, there's a TSB about that.

POWER DOOR LOCKS INOPERATIVE #63-81-06 - (02/15/1996)

SUBJECT: POWER DOOR LOCKS INOPERATIVE, REDUCED PERFORMANCE OF REAR DEFOGGER (REPLACE CIRCUIT BREAKER #15 AND TERMINALS)
MODELS: 1994-96 CHEVROLET BERETTA, CORSICA - BUILT PRIOR TO VIN BREAKPOINT TY134315 FOR 1996
CONDITION:
SOME OWNERS MAY COMMENT ON THE POWER DOOR LOCKS BECOMING INOPERATIVE WHEN THE REAR DEFOGGER IS "ON", OR THE REAR DEFOGGER NOT CLEARING THE GLASS DURING THE 10 MINUTE CYCLE AND POWER DOOR LOCKS BEING INOPERATIVE DURING THIS PERIOD.

CAUSE:
THE CIRCUIT BREAKER MAY OPEN WHEN THE REAR DEFOGGER IS OPERATING DUE TO POOR ELECTRICAL CONTACT WITH THE FUSE BLOCK TERMINALS. THIS MAY CAUSE A THERMAL CONDITION WHICH WILL ANNEAL THE FUSE BLOCK TERMINALS CAUSING FURTHER OCCURRENCES.

CORRECTION:
REPLACE CIRCUIT BREAKER #15 AND TERMINALS USING KIT #22638225 TO CORRECT THE CONDITION FOLLOWING THE REPAIR PROCEDURE CONTAINED WITHIN THIS BULLETIN. DISCARD THE INSTRUCTION SHEET INCLUDED WITH THE SERVICE KIT.

REPAIR PROCEDURE -

FOR ADDITIONAL WIRING, SPLICING, REPAIR, AND REPLACEMENT INSTRUCTIONS, REFER TO SECTION 8A-4 OF THE SERVICE MANUAL.

1. REPLACE THE TWO (2) CIRCUIT BREAKER FUSE BLOCK FEMALE TERMINALS FOR FUSE 15 (SEE ATTACHMENT 1).

A. REFER TO SECTION 8C FOR FUSE BLOCK REMOVAL PROCEDURE. IMPORTANT: REMOVE FUSE 8 AND CIRCUIT BREAKERS 12 AND 15 TO AID WITH FUSE BLOCK REMOVAL.

2. SOLDER THE CRIMP TO WIRE ON THE REPLACED TERMINALS.

3. REPLACE THE CIRCUIT BREAKER WITH THE 30 AMP CIRCUIT BREAKER, P/N 1252240, INCLUDED IN THE SERVICE KIT.

4. REMAINING PARTS INCLUDED WITH SERVICE KIT ARE NOT REQUIRED FOR THIS REPAIR.

PARTS INFORMATION:
PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:
FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION NUMBER: R2162 LABOR TIME: 0.6 HR

FIGURES: 00 ATTACHMENTS: 01

[3X00-Modified]

Ok wow they also say to replace the connectors...

I'll put this up on the home page as well.

Maybe this is why my 95 kept frying defroster switches and the 96 has no issues..

[weba]

Hmmh interesting, but it says that's only for 94-96. I've had this issue on 90, 91, 92 and 93

[3X00-Modified]

That might be the TSB for the 94+ models since the older ones will be slightly different... I wonder if there is a TSB for those too.

Cliff where did you get this?

[Cliff8928]

Off my computer... I have SI. I can PDF it if you want.

I didn't find it for the older models, but the same situation could certainly apply.

[Chad91GTZ]

There was just to much current draw there for both circuits to operate. The contacts will heat up and the resistance was to high because heat decreases the density of charge carriers, which is why you have to replace the contacts to fix the problem. The door locks wont operate even if the defroster is 'off' but had been used recently and the contacts havent cooled sufficiently. Its an easy fix.


Your problem stems from the same situation. Your circuit breaker isnt operstiong efficiently so its heating up, causing a higher resistance. Replacing your CB will likely fix your issue, but wont remedy the cause.

[BerettaMN]

Is this a problem on early beretta's too? my 91 never seems to stay on long enough to defrost it quick, and when i try to flip it back on it stays on for maybe like a minute then shuts off. pretty annoying in the winter! Do you guys think replacing the relay/fuse in the fuse pannel would fix this like on the other 94+ ?

[No Quarter]

Hi, just bought a 90 Beretta and joined this forum. And I have the issue that the defroster doesn't stay on long enough, and right after it goes off, the locks don't work. I have a circuit breaker marked 35A that gets very hot. Where can I buy replacement parts? Or what's the solution? Is there a TSB with instructions for my car?

Thanks