blackonblack02_Z

iTrader: (6)

Ok what is up with when I turn the rear defrost on it going out and then the power seat not workink for about 5 mins and then everything works again. I thought this was just a quirk with my 02, but then this morning my 01 did it too!!?? Whats up with this??

4150

iTrader: (13)

They are both on the same circuit, yeah its pretty annoying.

The circuit breaker tends to get weaker with age and trips a lot easier. Some people replace the circuit breaker with a 30 amp fuse to fix this but I'm a bit leary to do this myself, I'm going to try and find a new circuit breaker.

blackonblack02_Z

iTrader: (6)

Ya very annoying! I could understand if I was trying to move my seat while the defrost was on, but I am not. One day the defrost just went off and would not come back on. So i started pushing things to see what else wasn't working and WALA!! the seat no move-o. Just really pisses me off.

bad6as

iTrader: (17)

mine too, i just dont drive it enought when its cold any more to use the defroster.
just get a new breaker from gm

pjb

iTrader: (2)

replacing the breaker probably won't fix it. replace the breaker with a 30 amp fuse and forget about it. the breaker overheats and the circuit (rear defog/power seat) won't work until it cools down.

Greggy

they sell the 30 breaker at Autozone for like $5. I put in a 30A fuse with no probs. in heavy use.

98LS-WON

This works very well.

sixvi6-camaro

iTrader: (9)

replaced mine 30A fuse too. no problems after 2 years and I use mine a lot since I daily drive my car in the snow and all.

01ssreda4

iTrader: (96)

a fuse is just as good as a circuit breaker except if the fuse trips it will require a new fuse. considering you fuse it correctly, it will be protected and it shouldn't ever blow except in the event of a short. circuit breakers can be very troublesome with age.

LS1Lady02

This may sound like a silly question but how exactly does this aging circuit breaker contribute to killing a battery? My friend has a ws6 with the CB problem for the defog power seats and no matter what hes replaced from the CB its self to the actuator or power seat motor nothing has helped. Although i don't think he's every tried replacing the cb with a 30A fuse yet.

02LS1Z28BC

iTrader: (4)

OK, for the record. My 02 camaro rear defogger is reading .4 ohms (yes 4/10ths of an ohm) across its non damaged grid. If you do the simple current conversion of deviding the voltage applied (at those two rear grid terminals) by the resistance of that grid, you find out EXACTLY why the breaker is tripping. It is rated for 30 amps, the rear defogger circuit with the above values is drawing more than 30 amps. As an example, my voltage applied when I have the car running and switch on the defogger, was 14.24 volts. Doing the conversion, that is exactly 35.6 amps. That is an 18.8666% increase in the designed current of that breaker. If you load up the electrical system (lights/heater/stereo) and drop the voltage any, simply do the math and find the newer applied current across that breaker. Lets say after all the load you can put on the car (minus the power seat being moved, remember they are on the same breaker) you get 13.5 volts at that grid, the math shows the current at 33.75 amps (still 12.5% higher than designed current load for the breaker). If you get the voltage applied to the grid down to 12 volts exactly, you get the exact rating of that breaker that was installed. Remember my grid is exactly .4 ohms, your math may be different due to differences in your meter and how well you connect to the circuit at the rear grid. You MUST disconnect at least ONE of the connectors to get an accurate grid resistance before you measure the applied voltages, and not any values poluted by the circuit your testing (backfeeding through components). Replacing a resetable 30 amp breaker with a 30 amp fuse, will make that fuse hotter than a biach. Try it, open the fuse holder and start your car and turn on the rear defogger. As its working, feel the top of that 30 amp fuse you inserted in the breaker's place. It is simple Ohms law telling you what that circuit is drawing and why the breaker is tripping before the timer expires. I just wish there was a 35 amp breaker available. THAT will solve this design error and correct the breaker tripping before the internal defogger timer expires. BTW, my manual says the internal timer comes on for @10 minutes, then each time its rehit it times out in @5 minutes. This defogger actually only works as long as it takes the breaker to become overloaded by the excessive current draw through that circuit. The breaker is doing the job it was designed for, its just a bad design!

pjb

iTrader: (2)

bottom line:

replace the breaker with a 30 amp fuse, close the fuse block door and forget the problem ever existed.

fleetmgr

Using the 30 amp fuse in an already overloaded circuit is a bad idea. You've got a fire waiting to happen. Fuses don't react nearly as quickly as a breaker does, so if you develop a problem in that circuit...flame on.

02LS1Z28BC

iTrader: (4)

pjb, also make sure your insurance is paid and up to date. Electrical fires once started in the plastic rich dashboards of these cars, is beyond reasoning.

Has anyone ever seen a 35 amp breaker that would fit in this position? I would not want to put a 40 amp one there without doing a wire size traceout. In fact, I am not even sure there is a 40 amp breaker that would fit this position.

I remember growing up, my dad used a "no-blow" fuse in the old fuse panels. Instead of the screw in size, he just popped a penny behind the blown fuse. The blown fuse kept the penny in place. Yeah, a "no-blow" fuse. funny, isn't it? But it is the next step for those who keep popping those 30 amp fuses. I can see it now, 14 ga wire with two spade lugs crimped on them. Instant no-blow fuse.....

SilverV6Camaro

I remember I did the fuse instead of a breaker fix on my 99 Camaro about 4 or 5 years ago and it worked. I tried replacing the breaker with another 30 amp breaker and it DID NOT fix the problem. So definitely something changes with the defroster causing it to draw more current. Those breakers are thermal breakers that slowly start to actuate when the current is going through them, so the thought is that they trip before reaching 30 amps. Replacing them with an equal value fuse of 30 amps should not cause a fire, you're still protected against anything over 30 amps. The fix works, and you're still covered. I suppose a lot of detective work could uncover what causes this to happen over time (because it's not the breaker, new ones don't fix it) and you can fix the source of the issue.

02LS1Z28BC

iTrader: (4)

Reread number 11 above. It is a BAD DESIGN! Putting a 30 amp fuse in place of the 30 amp breaker may work BUT its heating up way too hot. You folks that plug in a 30 amp fuse, turn your defogger on and wait 3 minutes (your timer will hold it on @ 10 minutes first time, @ 5 minutes every time after that). After @ 3 minutes, touch the top of that 30 amp fuse you plugged in where the breaker was. Be ready to pull your finger or whatever else you put on top of that fuse quickly because your SKIN WILL BURN! The wire throughout this circuit (the rear defogger wires only) will handle a slightly higher continuous current, the breaker is the weakest link. If they made a 35 amp breaker it would suffice. I would not try anything higher than a 35 amp device or you run the risk of burning wires if any wiring downrange of the protective device shorts to ground. Its simple DC current math, the voltage applied at the grid, and the grid's resistance when isolated from the vehicle (one wire disconnected from the grid when making the resistance measurment). Anyone with a basic electronics course and a good quality multimeter can figure out why these breakers are popping.

01ssreda4

iTrader: (96)

Very simple solution to this problem::

Wire a resistor inline with one of the wires on the back glass to reduce current consumption.

02LS1Z28BC

iTrader: (4)

Oh my..... Wiring in a resistor in series with the grid, at these voltage and current values, the resistor would have to be a 506.944 WATT resistor. That is a 506.944 WATT, not ohm, if the grid is to do what its supposed to do (heat up). The resistor might possibly weigh 10 pounds (if there is such a wattage resistor out there. Definately NOT a good idea.

Got a package of ten 35 amp fuses on freebay, will test one when they arrive. For sure it will NOT be as burning hot as the 30 amp test one, might get a little warm though carrying an extra amp or two. Depending on which side of the rating the designers made them, they might just do the trick.

01ssreda4

iTrader: (96)

Paint the ten pound resistor blue and trick people into thinking you've got NAAAWWWWSSSS.

SparkyJJO

iTrader: (11)

If the 30 amp fuse doesn't blow, then you're not overloading the fuse...

I replaced my burnt breaker with a fuse and my defogger has been working great since I did that last year.