Since my rearend is broke I push the car out of the garage on Sundays, put a fan in front of each grille and one at the cowl induction opening and let the car run at fast idle (1500prm) for about 30 minutes. The temp stabilizes at 160 degrees doing this. Anyway, I usually stay out there and watch it to make sure nothing happens. Well I decided to go in the house for a few minutes and when I came back outside I saw smoke coming from under the hood. I opened the hood and the damn thing was on fire. The electric fan fuse holder had caught on fire and set some wiring, vacuum hoses and the inner fender flap on fire. I'm lucky I came out when I did and even luckier I had a fire extinguisher in the car AND another in the garage. I used the one in the car up and had to use the one in the garage to put the fire out completely. Another thing is since I didn't plan on driving it for a year or so I had cancelled my insurance. Luckily the damage was limited to some burned wires and vacuum hoses and the fender flap. Scared the crap out of me. That was a close call! I thought when the fuse fails the flow of current is interrupted and all is well. Why would the fuse holder fail AND catch on fire??? It was connected from the fan control box to the alternator per the wiring instructions. :confused:

 

Can't really say what happened with the fuse... but glad the damage to the car wasn't any worse that it is. :yesnod:

 

I am in the electronics industry. If the fuse fails, it should blow open clean - no fire. You've got fast blow and slow blow fuses. My guess is you have a slow blow fuse to allow for the repeated usage high inrush of current required to "kick" start the fan motor.

The motor would need to be shorted out or your wiring shorted to a metal ground before the motor but after the fuse for it to blow.

Check your wiring set-up for a short- such as a pinched wire or exposed metal of any sort. If all looks good try it again under supervision and see if the fuse blows again. If so it could be the motor. You can pull the fan and try the test out of the car to see if fuse blows again but bypassing the thermal switch.

If you have a bad fan, the manufacturere may be laible for some damage. Hold the fire fuse for evidence and call the fan manufacturer.

Normally in high current wiring, the possibility for fire exists with connections that are not solid and they start to arc. This could be the story of the fuse holder to fuse connection. Do you recall if this was tight?

It also could be a fluke fuse that lost its seal and burned up but didnt completly open up as soon as it should have cleanly and caught fire. Stranger things have happened.

Best of Luck.

PS I alway liked your Vette. Do you have any pictures to post of the ol boy? Its been a long while since I saw any.

Brent...

 

Man, that is to bad, glad it was not more. A lesson for us all to remember. :cheers:

 

Glad it didn't get any worse. get those extinguishers refilled .... :seeya

 

Damn! Glad you caught it when you did- could have been SO much worse. Good luck getting it sorted out.

 

:eek: that makes me want to drive up to storage and disconnect the battery, and i drive the vette about every other day!

 

Man I'm glad you found it without it being a total lose :eek: ! I love your car, & look forward to it's return to the road :yesnod: .

 

Any high current fuse holder is suseptible to that kind of overheating, what happens is it gets corroded under the hood, or anywhere for that matter, and as such drops voltage across the bad connection....dissipates power there, gets hot and burns, eventually....what is needed is a sealed modern fuse holder with those bladed color plastic fuses....a 30 amp holder is common blister pak thing in parts houses....
I had to put on in my old Dodge van for the heater motor, kept burning up...
POS.....and also on a dodge the fan speed switches for the same reason keep burning up....just plain cheap junk.....

GENE

 

:iagree:

 

:withstupid: :withstupid:

 

" Note to self.....Buy MORE fire extinguishers"

Glad it wasnt a disaster!

 

Hey Nastee,
Was the wiring run through a relay? If not, that would be a good idea during repairs. The biggest reason I can think of for the fuse holder to light up is a fuse rating of higher amperage than the wiring could handle. Anyway, at least you caught it in time; fire sux... :mad

 

I have seen this before with in-line fuse holders (glass fuses), the kind that look like a cylinder. I refuse to use them anymore and have switched over to modern style blade fuses. As Gene said, the old style start corroding, resistance increases and they get hot.

 

I always hate reading these types of posts. I am so glad nobody was hurt and that the car is mostly ok. That must have been a heart stopper. Fire in a car frightens me so I definitely carry fire extinguishers. It's good to hear that you were prepared as well.

 

This is one of those things that scares the bejesus out of me. I wouldn`t wish this on anyone. I just put an electric fan on mine about a month ago. It has the new style bladed fuse in it. But there are so many things that can go wrong with wiring and such, it could happen anywhere on one of these old cars.

 

hey nastee, you running the flex-a-lites? i'm running the 210s and have seen the same thing your talking about. there have been several times i've had to replace the fuse holder because it gets so hot it just distorts and almost colapses on itself. mine caught on fire as well, too. i was going to the drag races one night and just as i pulled in to be teched, i started to notice smoke coming from under the hood. the hood was already 'popped' so i got out and saw that the fuse wire was glowing red and the holder was melting while i was there. i just yanked the wires apart to break the circuit and had to borrow a fuse holder to fix it.
now this may or may not apply to you depending on which fans you have and how you've wired them but i have a theory for why this is happening. my theory is that the fan manufacturer figures on a more standard configuration with the battery located right next to the radiator where there is a maximum span of about two feet from power supply to power consumption. considering that, the supplied 10 gauge wire and fuse holder is 'sufficient' for the load but by no means overkill. in my application, i felt the best place to run that kind of power was to go all the way over to the positive stud of the starter solenoid. this increased the total length of wire from supply to consumption by 3-4x. the resistance of 7 stand (i think) 10ga wire over that distance is way more than it can handle. so what your seeing is the wire is what is catching on fire due to the heat. it's not blowing the fuse because your not overamping anything.
although i haven't fixed it yet, as i see it the fix would be to increase the size to 8ga and maybe a fine strand wire and larger fuse holder. i would put the fuse holder closer to the power supply and run the wire the most direct route as possible to decrease the length, and resistance, of the current to the fans.
hope that helps. if not, at least you know i feel for ya :cheers:

 

All this talk of fuses catching on fire makes me want to go and get a new under dash fuse box. Has anyone here upgraded there fusebox to the new blade style fuses? Was it easy? And where can I get one made for my vette?

 

What size/type of extinguisher was it that you kept in the car and used up without extinguishing the fire? That is kinda scary right there.

Glad you caught it when you did!

Chris

 

I've had fuses melt the solder out of the ends before. The fan fuse in my 944 gets so hot it will melt the solder from glass fuses. I had to start using the german "open style" fuses (no glass, exposed fuse element). I had a hard time troubleshooting the problem because the solder would harden when it cooled off and then the fan would work again. Strange stuff.