FJ62 heater circuit breaker & relay (1 Viewer)

[Spook50]

So yesterday I had my A/C going full blast and for the first time in my 62's life, the heater breaker popped. I reset it and it seems fine for now. I did some digging and apparently both the heater relay and the breaker itself can deteriorate with age and start allowing too much current to pass through, leading to regular popping of the breaker. I've got a newer fan in there and replaced the fan resistor about 4 years ago, so if my breaker keeps popping, I want to go ahead and replace both the relay and the breaker. Are either still available new?

 

[John Staton]

Mine used to do this on high only....my fix was to bypass the relay. Pic in thread.

A/C blower motor wiring by-pass.

Assuming the CB are weak, how bout crimping some flat blade terminals on a 30a inline fuse holder, plug it into the c/b socket at the fuse box and see if the 30a fuse holds?? No harm at all in doing that. You should learn something at any rate. Drove around the street until the breaker...

forum.ih8mud.com

 

[Spook50]

So I replaced my circuit breaker with a new Toyota part and after running the A/C on high for not even five minutes today it popped again. Then with just the fan on high (no A/C) it popped after about 20 minutes on the highway. My motor is only 3 years old (Four Seasons from Rockauto), so I'm suspecting it's the relay introducing too much resistance into the circuit. Anything else I can investigate here? I doubt it's the blower resistor because I replaced it with a new OEM part about 4 years ago.

 

[Spook50]

I'm resurrecting this thread because I'm still having this issue. Though it doesn't take as long in cooler weather, the new OEM breaker still pops when the front blower is on high, regardless of whether the rear blower or A/C are running or not. I used a clamp meter that reads DC current, and with both front and rear blowers on high, plus the AC running, it shows only 16.6 amps being pulled through the breaker's connection (I swapped the breaker for a 10 AWG jumper wire so I could measure the current at that exact spot. The breaker is getting much hotter than the "power" breaker right under it when the blowers are running too. It seems to me without pulling one apart (should've saved the old one so I could do this) that these are thermal breakers that can handle a brief spike in current, but will heat up and pop when sustained current exceeds their rating. Still, only 16.6A shouldn't be anywhere even close to an issue for a 30A rated breaker. I'm going to clamp the terminals a bit just to make sure there's good solid contact when the breaker is installed in case a small amount of arcing is contributing (doubt that's the case but want to eliminate that possibility). I'm going to order a new OEM relay as well. Doubt that's the issue but I'm trying to eliminate all possibilities.

This is kind of going hand in hand with my blower restoration thread, in hopes that both threads will help other 60/62 owners who run into these issues in the future.

@John Staton I'm rereading the thread you linked and it's given me a few more ideas of what to look at. My hope is that I can continue to use factory wiring without any modifications.

 

[morganism]

The blower resistor in the ducts may be loaded up with gunk from the exterior air intake. I would pull it and clean. ?

 

[Spook50]

The blower resistor in the ducts may be loaded up with gunk from the exterior air intake. I would pull it and clean. ?

This one's been in there a little less than 5 years. The original was 27 years old and in good shape (just the potting around the resistor coils was disintegrated). Even then, when on high the resistor is bypassed, so if it was shorting out and causing the breaker to pop it would be on one of the three lower speeds.

 

[John Staton]

I'm resurrecting this thread because I'm still having this issue. Though it doesn't take as long in cooler weather, the new OEM breaker still pops when the front blower is on high, regardless of whether the rear blower or A/C are running or not. I used a clamp meter that reads DC current, and with both front and rear blowers on high, plus the AC running, it shows only 16.6 amps being pulled through the breaker's connection (I swapped the breaker for a 10 AWG jumper wire so I could measure the current at that exact spot. The breaker is getting much hotter than the "power" breaker right under it when the blowers are running too. It seems to me without pulling one apart (should've saved the old one so I could do this) that these are thermal breakers that can handle a brief spike in current, but will heat up and pop when sustained current exceeds their rating. Still, only 16.6A shouldn't be anywhere even close to an issue for a 30A rated breaker. I'm going to clamp the terminals a bit just to make sure there's good solid contact when the breaker is installed in case a small amount of arcing is contributing (doubt that's the case but want to eliminate that possibility). I'm going to order a new OEM relay as well. Doubt that's the issue but I'm trying to eliminate all possibilities.

This is kind of going hand in hand with my blower restoration thread, in hopes that both threads will help other 60/62 owners who run into these issues in the future.

@John Staton I'm rereading the thread you linked and it's given me a few more ideas of what to look at. My hope is that I can continue to use factory wiring without any modifications.

I

I have had mine blowing both hot and very cold for an extended period of time without any issues since I made the mod and stopped using that breaker. Happy to send you one if you want to try it. If I remember I ordered a 5 pack when getting those off of ebay and I have extras. I like to have stuff OEM as well, but this was an easy fix and I have other stuff to chase and fix and really cannot afford to be out and about in the hot Texas weather and loose AC. Just PM me your address and I will send on to you this week if you are interested in trying it. Doesn't change anything other than the form factor of that connection.