rear window defroster question

[No Quarter]

Just as a FYI, I bought this TSB kit at newgmparts.net:
Item: KIT- TIME
Price: $45.95

And it works! Even with the old circuit breaker and timer module. It now stays on for 8-9 minutes, and you can use the power locks at the same time. Beware that if you need a new timer module, the one include was wrong shape of terminals for my 90 Beretta.

[weba]

I'v replaced just the circuit breaker with couple different models and had no luck. Also tried one with push-button reset but it just snaps back out instantly after the first 20 seconds it stays on.

I guess you Really change the wire ends too..

[jeff540]

I'v replaced just the circuit breaker with couple different models and had no luck. Also tried one with push-button reset but it just snaps back out instantly after the first 20 seconds it stays on.

I guess you Really change the wire ends too..

What I did was popped the 2 circuit breaker terminals with a small screwdriver,out the back of the fuse box,fed them down where the circuit breaker will now be under the dash,cut the old terminals off,gave you more slack on the cable to crimp on new terminals,yellow 10/12 gauge female quick-disconnects,they plug right into the original circuit breaker,electrical tape it up when done,and add a zip-tie so the tape don't unravel when the heat is on.

the NEW fuse location is now under your dash,the old in the fuse box is empty now.

Now go back to the rear window and pull the old terminals off the defroster,not much room here,take your time,use pliers if you really have to,not much wire back there also,just enough to cut off the old terminal and add a new yellow 10/12 gauge female quick-disconnect,make sure the new terminal fits tight,if not get your crimpers and crimp it lightly so it will be secure,now go and do the same to the other side

Left of the Driver's seat my 95 Z26 had a ground connector pull sill plate,roll back carpet and you should see where it is grounded,if it looks rusty,cut old connector and add new,make sure you are attaching new connector to good metal. That is the power door lock ground,and possibly rear defroster ground also,since they use the same circuit breaker.

My power door locks quit,there is a fuse under the steering column that was blown,it was the power door locks,driving lights,horn fuse,replaced that blown fuse and replaced the connectors I stated here,and i will tell you what,power door locks,rear window defroster now work fabulous. cheap fix and it works. good luck! not that hard to repair.

[Dukenukemx]

Hope nobody minds me bringing up this old thread, but I'm trying to fix the same problem. Owned the car for 16 years, and the defrost always cuts out soon. Since it's winter, figure I try to fix it.

Couldn't find the GM kit to fix the problem, so I decided to find the circuit breakers and wire them in myself. Rockauto listed the Standard BR34 and the Delco C716 for my 90 Beretta. So I figure these were it. Got them, and they're far larger then the ones in the car, but I figure that's how GM fixed the problem. Made a quick wire harness to try it out before cutting any wires, and within seconds the wire gets hot and begins to smoke.

I got a photo of the circuit breaker for anyone to check out. Is that correct? If not, then what circuit breaker will work?

[3X00-Modified]

If the wire is getting hot and starting to smoke your using too small of a wire gauge, or there is a short in the system somewhere

On a second note... how are you testing this?

[Dukenukemx]

I just made a quick wire harness to test it out. Just pushed the wires into the fuse box and switched on the defrost. I can get a thicker wire to hook it up proper, but this was just a test. I plan to cut the wires and solder. But are those the proper circuit breakers? The new ones are far larger then the old ones.

[3X00-Modified]

I'm not sure on the circuit breaker size but 12v 30amp should be enough but if the wire you have between that and the fuse panel isn't large enough then it will get too hot... that's electronics 101

[Dukenukemx]

Just need to make sure it's the correct circuit breaker before I put a thicker wire. If someone has a pick of the ones that came with the GM repair kit, that would help a lot.

[3X00-Modified]

your missing the point... Without the proper wire your test will NOT WORK. You need to properly support the current feeding to the relay to test it otherwise your wasting your time and you'll just be melting wires.

I just did a 30 second search on google for the PN of the circuit breaker listed in the TSB P/N 1252240 and I came up with this page

http://www.wbparts.com/search.cfm?q=1252240&parttype=2

The last two with title circuit breaker are listed as 30 amp 12 volt.

[Dukenukemx]

Thanks, the P/N 1252240 shows to be correct. The ones I have are huge or overkill. Guess I'll return them.

[BerettaMN]

Did you ever figure this out? I tried a new breaker before and it worked for a little while fine then just returned to shutting off after a minute or two and less then a minute after re trying again. I know the system works because you can see the window starting to defrost. Just cant figure out why. I was thinking about swapping out the washer/defogger switch for a new one and seeing if that fixed it but they're 40$

[3X00-Modified]

You need to test/inspect all your connections and find out which one is creating the most resistance because that's generating excess heat causing the breaker to flip off.

[BerettaMN]

Yeah I'm not good with wiring diagrams, but was going to clean the ground on the driverside for the locks/defrost circuit and clean the contacts on the back window and fuse panel. Get the multi meter out and check at the fuse panel and rear tabs. Are the back interior panels easy to remove to access the glass? I can't even see the tabs right now.

[3X00-Modified]

They are all just the standard door style push clips... Just go easy pulling them apart because the plastic likes to break on the inside that secures the clip to the panel.