Melted fuse to electric fan? (1 Viewer)

[projectfj]

I have a 79' fj40 with an advance adapters 16 inch SPAL electric puller fan. It's done good to cool the 350 off for the most part, but today I noticed the fan didn't kick on and it got hot quick. I pulled over to find the 40A fuse and holder that came with the kit had melted pretty bad. It's under the hood, but over by the fender well as far as I could get it from the motor. Any ideas on what happened? Also, should I get the same type of fuse holder or get one of those that holds the glass cylinder fuses? And what size fuse would you recommend? Thanks

 

[spotcruiser]

Typically, corroded connections (high resistance connection) create heat and melt surrounding plastic. To help prevent that in the future, you can make sure the connections are clean (blade and spring clip, as best you can) and coat the metal parts with a very, very thin coating of dielectric grease. The blades are easy; smear some dielectric grease between your thumb and index finger and then rub the fuse blades. The spring clips are a little more difficult. I coat a Q-tip with dielectric grease, rub it into the cotton, and then rub that in/over the terminals as best I can. I will sometimes use a toothpick, if needed to get down in the terminals.

 

[cruiserjunkie]

how long has this system worked for you? Electric fans pull plenty of amps at start up. If its proven I'd go with the same type setup. I use a solenoid it is a bullet proof way to never have a similar problem but I use a Taurus fan so it had twice the issues probably.

 

[Tools R Us]

The ones that I have seen smoked like that were from more amps than rated. The whole thing gets hot and melts. I don't use that type of holder for anything over ~20amp.

 

[projectfj]

It's worked nicely for about a year now. I went and got a new fuse holder and a box of 20A fuses, because I read in the fan's instruction manual that a medium profile fan should pull about 20A (30A max). However, when I cranked it and let it warm up, the fan again never kicked on and the fuse blew. I put another fuse in and it blew on start up. Any ideas on what it could be?

 

[Weber Sarge]

I'd bet the fan motor is the issue , pulling way more amps than it should .
Sarge

 

[bj40green]

In line fuses like the one you have come in different wire sizes.
Have a look here: In-line fuses

Fan's draw easily 30 or more Amps with an in-rush current of 60 to 80 Amps.

Yours is melted because the fuse holder clips were not tight enough or the connection from wire to clips were not good manufactured.

Buy one with the biggest wire size you can get. AWG 8 or 6 or 4.
The point is that even in a 18 or 20 gauge wire in-line fuse you can put a 100Amp fuse and that's asking for trouble. In such cases the wire burns up before the fuse blows.

Rudi

 

[projectfj]

Thanks so much for all the help