GotGrunt

iTrader: (1)

Got it... thanks!

I just replaced the breaker with the fuse and the defrost button still doesn't light up. I'm assuming it's the switch?

wssix99

iTrader: (5)

Probably the relay. See post #28 in this thread.

GotGrunt

iTrader: (1)

I guess I'm gonna try to find a used HVAC unit since all I really need is the relay

Ray396

iTrader: (6)

I have the same problem with my 2002 camaro. Checked and replaced fuse and tried a circuit breaker, nothing changed. push rear defogger button, hear something click. removed the heater and A/C control panel tried another one from a junk yard. no good. So I removed the rear defogger circuit board and switch assy. powered it up and started tracing the current flow, looks like the relay is bad, you hear it click. But I think the contacts inside are bad. I was able to remove it from the circuitboard, found the relay on line for $2.50, I ordered 2. I will let you know how I make out, when I install it.Ray

ehksohset

iTrader: (1)

Ray, so how'd it go? It looks like I'm having the same issue. I just replaced the breaker with a new one, but no dice. I suppose I will try a fuse next, and failing that, I might have to start looking for a relay. Do you have a website/part number where you found yours for $2.50?

Ray396

iTrader: (6)

Hi, It worked out fine, fixed my nephews car and fixed the other one and sold it. I have check where I got the relay from. I have look for the paper work. If and when I find it I will let you know.Ray

Ray396

iTrader: (6)

Hi, I can not find it. What you have to do is remove the A/C heater control panel, then remove the circuit board for the rear defogger. Then get the number off the white relay on the board, and google it. Thats what I did.Ray

FirebirdStud

iTrader: (5)

So, This seems to be a reoccurring issue. In my fuse panel, the 30amp fuse I installed instead of the breaker for the power seats and rear window defogger keeps melting. I dont have power seats, so I know it is only the rear window defogger giving me the problems.

What gives? This is the second fuse that is melting due to this issue!

#12 in this pic


The fuses. The really effed up one was the first to go, two years ago. Now the second one has signs of boiling

WhiteBird00

iTrader: (4)

Melting (but not blowing) fuses have two common causes - really cheaply made fuses or some kind of bad connection at the fuse socket causing excessive resistance. Try using a brand-name fuse (Bussman or Littlefuse) and cleaning the contacts in the fuse panel. Also make sure the fuse socket contacts are making a tight connection with the blades of the fuse.

FirebirdStud

iTrader: (5)

Ok, Ill have a look at this and report back. This isn't a common issue when replacing the breaker with a fuse??

WhiteBird00

iTrader: (4)

No, not at all. There is no reason for a fuse to cause any more heat than a circuit breaker.

FirebirdStud

iTrader: (5)

I looked at the fuse holder. It looks clean. There is no rust or anything. The fuse makes good contact with the fuse holder.

I tried to take an ohm reading of the two terminals, but it kept saying open circuit. Is this normal? I measured the radio one and got a reading, as well as one other random fuse.

I recognize that in order to work the defog button needs to be pushed, so measuring the resistance might not be helpful with this circuit.

What else can I look for?

ShovelMan

It's 2014. I'm in College Station and Houston and it's freezing.


And it's March.