Melted fuse

[TulsaSpider]

Well I took it out for a spin this evening and it started getting hot as I was getting home. I have the non functional fan switched bypassed with a toggle and 10 gague wire till I can replace it. I just got my console back together. I checked the fuse and it was verry hot but when I touched it the fan kicked on so I let it blow a while, then it kicked back off and I looked under there again and the fuse had begun to melt. It was a plastic fuse that I had gotten at the parts store in the correct configuration except they weren't ceramic. Do I need to find the ceramic ones? They don't seem to have the rating on them I was using one of the red ones there, are they rated the highest? Tomorrow I am going to remove the old A/C fixture that basically blocks access to the fuse area, and clean and try to bend the contacts so that the fuse fits tighter, disconnecting the battery of course. The fuses do seem to be sorta loose, I hope that takes care of it. I suppose the ligts and the fan run on this same circuit? as I haven't had any problems like this before tonight, but then again I have run it many times at night, so I am sure hoping that cleaning and such takes care of it. Now for some ice on my finger!!
Clark

[rlux4]

The GBC fuses we use do go up to 25 amps, but I've only seen 8A and 16A used on our cars. The red one is 16A, white is 8A. I've had the best luck getting the ceramic GBC fuses at Autozone around here.
Ron

[So Cal Mark]

plastic fuse? The terminals need to be tight, otherwise you have lots of resistance, and that builds heat

[mbouse]

plastic verses ceramic makes no functional difference until you overload the circuit, but that fuse should have blown before it melted. what was the fuse rated? does your fuse panel still have the cover that hides the fuses? AutoZone, 8A ceramic fuses are like $2.65 for a sixpack, not bad.

take the negative cable off the battery and clean ALL of your fuse connections with steel wool or emery cloth; be dang sure there is no battery connected if you use steel wool . then, as Mark says, tighten each of those connectors by pinching them closer together with your fingers.

then, getta wiring diagram or Fiat list of fuse ratings for each connector and put the proper rated fuse into each. I suggest a brand new fuse for each connection, saving those you took out for spares.

Then reconnect the battery.

if this happens again, i would suspect either a shorted wire (very probable) or a fan motor that is going bad (unlikely).

[TulsaSpider]

Well I did all the cleanup and pinching together and so far so good, I ran it about 30 min and it did get hot, but seemed to hold up Just fine, it looks like this had been an issue before so I'll keep an eye on it thanks guys!!!
Clark

[So Cal Mark]

if you have an ammeter, you might check the draw through that fuse. It sounds like a good idea to change the system into a relay for the fan rather than have all of the current through the fuse

[TulsaSpider]

That sounds good, How would I achieve that??

[mbouse]

i respectfully disagree on adding a relay at this point, Mark. i wholeheartedly agree with measuring the actual current draw across the fuse. reduce and eliminate the relative measurement of "feels hot".

if the fuse is truly getting hot and it is the correct rated fuse for the circuit, there is a problem with the circuit. adding a relay will not solve the underlying issue behind the symptoms, just transfer the symptoms to another location.

that problem will not go away by itself.

i may be wrong, but i don't see anything else on that 16Amp circuit. MY fuses don't blow for my rad fans; i don't hear anyone else chiming in to say that they are experiencing these issues. I gotta believe that there is an issue with this particular fan, or fan circuit. Measuring the amp draw across the fuse is the best place to start. Set your multi meter to amps, and put a probe on either side of the fuse and read the gauge. what does it read?

[So Cal Mark]

you can disagree if you want, but I see lots of Spiders with fuse box problems on that circuit. With the poor design of the fuse box, it's common to have high resistance at the fan fuse. By converting it to a relay, only about 1 amp will go through that circuit to activate the relay. If you don't want to do the upgrade, don't do it. But I seem to recall you advocating the headlight relay upgrade, and this is the exact same thing. Only it's on the fan circuit

[TulsaSpider]

I will check it tomorrow, we have the equipment at work. Should I check it with the fan/lights on and car running then?

[So Cal Mark]

check it with all of the load on the circuit

[TulsaSpider]

13.25 amps with everything I could think of on.

[rlux4]

It's still getting hot? At that draw is shouldn't. It's starting to sound like a bad spot in the wire somewhere. If there is a frayed section then you have 13.25 amps trying to get through less strands of wire, this would cause resistance, the cause of heat. Or a gound connection is not solid, same result.
I envy you Clark, you get to trace a wiring problem!
Ron

[mbouse]

of course, none of us can verify if a p.o. has not changed any wiring on this circuit, but there should be nothing else on this fuse according to my wiring diagram.

and i agree that 13 amps should not cause your 16 amp fuse to over heat. was it hot to the touch when you made this measurement? was the rad fan ON when you made this measurement? is there a manual switch controlling your rad fan, or (as far as you know) is this circuit wired according to factory specs?

[So Cal Mark]

if the fan was off, and nothing else is wired into the circuit, the draw should be 0. 13 amps sounds high for just the fan.