So, some background for everyone. I have just recently installed an HHR efan paired with the Derale controller. Have had NO issues what so ever and I have been loving the extra pickup. Well I just went on a 1200 mile round trip to Atlanta for business and on my way back I noticed some slight overheating and when I got stuck in traffic the overheating got really bad. Well cranked the heat and turned the AC off and It was manageable until I just got home. did some digging and found out the fan wasn't turning on anymore (kinda knew that was the problem) and the 30 amp inline fuse that's in the power wire coming from the fan into the Derale control module. Picture is below. Can't say that Ive seen a fuse blown this bad before. What would surge this bad to cause this? the only thing I can think of is a power surge from a bad alternator, voltage regulator going bad. Had this problem in my 84 z28 and I just kept going through Ignition modules because the alternator was cranking out 14amps. Thoughts?

 

in my experience that looks like it was running close to the blowing amps but not high enough to actually break the link between the poles. the problem with the cheap high amp fuses is that the plastic is just that... cheap, it can sometimes fail before the link will blow. I managed to work around this by taking the single fuse and putting two fuses in parallel in its place. of course the parallel fuses were half the rating of the single fuse. according to current laws (electric not legal) the amps entering a junction is equal to that leaving no matter what the combination. so by running paralleled compared to single you split the amps through each fuse in half. this in theory should reduce the heat generated from resistance in each.
yea that was kind of a tirade but yea... hope it helps some

 

That's definitely a heat issue that caused the problem, but why the heat? There are various options for this answer including the following:

• the fuse wasn't doing it's job - although rare, it does happen that the fuse won't blow at it's rating. To overcome this, try a new brand name fuse, parallel 1/2 value fuses as already mentioned, change to an in-line breaker.
• the wiring gauge is too small for the power consumed.
• bad contact somewhere close to the fuse causing the wire & fuse holder to heat up (this could even be the fuse holder if the wire, wire gauge, & connections are all good).

The fuse should blow way below any heat damage like that happens, so I'd guess it was a bad fuse. Any discoloration to the wires connected to that in-line fuse?

 

Thanks for the help thus far. I didnt bother to look at this but I noticed the electrode was still in tact. So it didn't blow, It just got WAY too hot. I think I am going to try a new fuse and inline fuse unit because the on that came with the derale was a fairly cheap one. I'm also going to try relocating the fuse to a different spot in the line and see what happens.

 

I would certainly consider the same thing in your shoes. When you do this, make sure that you use a fuse holder and whatever wire you need that will handle 30 amps.

 

I agree with Alfons. On that note... what gauge of wire are you using to power that fan?

 

^ that....my question too...seems like the wire burned before the fuse blew....

 

I would recommend at least 12 gauge wire... if not 10. When those fans "spike" at first startup, it can really destroy wiring if its not up to the task. Ask me how I know.

 

i use this table for all my wiring to make sure im more than conservative with my loads

http://www.powerstream.com/Wire_Size.htm

 

sorry for the delayed response, but I'm using the wires that came with the Derale which is 12 gauge. and that's the gauge of the wire on the new inline fuse unit as well. But no issues thus far with the new fuse, I'm going to check again tonight.