19864runnerHawaii

Hey guys i am in DIRE need of youre help
Got a 1986 4runner. Im running A electric fan (previous owner put it in) Giving me CONTINUOUS problems!!!!! Heres got I have it set up.

Electric fan, Grounded to the chassis (10ga, made sure its SOLID, perfect ground)
Positive ran from battery, to fuse box (40amp maxi fuse), to 50 amp toggle and around to the fan to finish the circuit (10ga)

PROBLEM: I keep melting fuse boxes and the wire from the fuse box to the toggle is burnt (insulation) and the wires going to and leaving the toggle (bolted to 50amp toggle) have burnt insulation as well.
I dont know what the fan is from.

I CANT FIGURE OUT WHAT TO DO!! IVE REPLACED NUMEROUS FUSE BOXES AND TOGGLES AND IT KEEPS HAPPENING! PLEASSEEEE HELPPPP!!!

Mitchell12

Are you using a relay? what gauge wire?

19864runnerHawaii

I am using 10ga wire throughout (almost identical matching the factory wires from the fan itself)..
And no I am not using a relay..... How exactly does that work? Like I said, I just have my battery-->fuse box (40A)-->50A toggle-->Fan.. With the fan grounded to the chassis (made sure its a good ground)....

I dont know too much when it comes to electrical...

Mitchell12

Well basically the relay will help save your switch from arcing and burning internally. That might help your problems.elsewhere as well.

crawler85

get thicker wire or a fan that draws less amps.

am I correct in assuming that it just recently started to happen?

if so, replace the fan

BigBluePile

iTrader: (3)

Use a relay. Very simple. That fan probably pulls more amps at startup than at any other time.

crawler85

But the wires on the high amp side of the relay will still melt.

He needs a new fan or thicker wire, if this ever worked normal before, he needs a new fan.

BigBluePile

iTrader: (3)

Does the fan actually work? You know, when its not actually catching on fire?

bruzer

The 10 ga. wire is definatly heavy enough, the 40 amp maxi is probably over kill. sounds like a bad connection or most likely a bad fan. Typically a electric fan only need a 20 amp service (on average).

Marc

What do you mean by "fuse box"? That might be the weak link.
But really, a thermal controlled relay is preferred.

crawler85

or the red wire can be grounded out somewhere and causing a short, melting the wires.

19864runnerHawaii

Hey guys, Ok there was a lot of questions to answer...
-Im using a maxi fuse box (the kind for stereos)
-and the 10ga wire im using has the THICK copper strands, not the thin kind. And it matches nearly the exact size of the wires on the fan.
-As for THE FAN, When i bought the truck it was giving problems. So I tried fixing it and its just the SAME reocurring problems. The fan works fine, and recently i got it to work for the longest I ever had. Like 2 months without problems.
-It works but after months of using it, the fuse box melts,(totally hashed) and the wire leaving the fuse box to the toggle has melted insulation.
-Also the 2 wires connected to my toggle (in and out) have black burnt insulation.

I used to blow fuses and toggles so I upgraded fuses, toggles, and gauge wire, to this point (after continous upgrades and still blowing them) and so this is where i got it to work best so far, and its doign this now.
Its not blowing anything, but now its melting wires and fuse boxes.

ALSO Ive checked all wires. It was doing this when i got the truck so I replaced ALL wires to my own 10ga.

Im soooooo lost already!! Im considering doing away with it and just running a stock fan and shroud already to get rid of this issue....

19864runnerHawaii

WHat youre saying is what I i was thinking. But what everyone else is saying, due to my burning wire and fuse box melting problem, I need BIGGER wire and a fuse with better connection.
WHere do you think I could have bad connection?

crawler85

Lol you are an accident waiting to happen. you don't upgrade fuses if they blow. you figure out why the fuses are blowing and fix it.

replace the fan and use the proper size fuses

slow-mo

Even though you state you have limited electrical knowledge...

what should be done is determine how much current (amperage) the electric fan is drawing from the battery. One way is to connect a multimeter capable of handling higher amperage in series with the circuit. This would make the current flow through the multimeter so the multimeter will read the amperage. The other way is to get an inductive amp clamp that will read amperage still using the multimeter.

Doing this will dermine what size fuse to use, that is if you don't have any documentation from the fan manufacture. Of course, this is for a properly working working electric fan. I would say if you can, do some research on who makes the fan, then check the manufacture's website as to the fuse amp raiting.

However, from your desciption, I would also, like the others, suspect a faulty electric fan as well. If the fan is faulty, it would draw more current (amps) through the whole circuit, greater than it is designed for (what you created) and cause high temperatures. The high 40 amp fuse is not protecting the wires or fuse box from melting. Even though you say the fan is working, it may be still drawing too much current for the circuit.

Stu Pidasso

I would check my ground wire and my ground connection. Make sure it is excellent. My fan likes 25 amp fuses. It is a 2100 cfm unit from Summit racing with 2 speeds. I have a Hayden thermostat and relay wired in line with my fan. You may also have a bunk fan like some of the other guys on here have said. 40 amp fuses are pretty hefty. You gotta consider many vehicles only run 25 amps to the cigarette lighter and some vehicles have 60 amp fuses going to their starters.

Stu Pidasso

This guy right here is on to something. This is what I would do. Furthermore, I think that this is an excellent way for you to learn more about electrical. Nothing on my truck scares me or intimidates me. The only way I have learned is by getting out there and doing it. I think you can fix this and I will be stoked when you do.

19864runnerHawaii

HEY GUYS! i literally JUST pulled the fan out of my truck to find that the harness, (where the fan wires plug into the harness, so you can hook up your wires to the car) had the ground prongs melted and screwd up in there.
And the plastic around where the prongs go in, is all black and melted.

This being said, could the fan be bad??

19864runnerHawaii

quick question maybe you guys have a clue. I use the royal purple antifreeze additive (thingy that makes your car run cooler) and with the electric fan, My truck is running at about 130*F under normal low rpm conditions and in fifth gear on the open road going 55 it runs about 160*F ........ I know thats on the cooler side, but how cool do you think itll be with the stock fan and shroud? not higher than 190 right??

bruzer

1st of all, not everyone is an electrician. who ever is telling you to up size your wire and fuse should not be playing with electricty.

2nd, could'nt tell you if or where you have a bad connection. was just a thought. And just because your fan turns dosent mean its not drawing to much power/amperage.
A clamp meter is an easy way to check amperage thats being drawn through the wire.
Im running a 14" electric fan on 12g. wire and a 20 amp fuse no problems.


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