Fan Fix inline Hot Fuse -20a - Fuse melting!!!

[Beachdrifter]

Hi all,

So I have Hervey's fan fix module. And there is a 20 amp fuse that connects to it. I noticed the little thing heats up SO much that it burns my fingers when I touch it. I also noticed the fuse is melting on one of the posts. I have Hervey's updated fans as well. I guess it has always been this way, but I never paid attention to it until I took a closer look.

What can I do to mitigate this hot current? This doesn't seem right. Any risk of fire here?

Thanks for any insight,

--Randy

[Ron]

It could be anything from a poor connection at the fuse (dirty/corroded, fuse holder tension weak), fan(s) pulling too much, grounds....If you have access to a meter that can handle 20+ Amps (many of those floating around only go to 10A), pull the fuse and measure it right there...

[Bitsyncmaster]

Does that fuse handle both fans? I would expect you to have two fuses of 20 amps, one for each fan.

Note:
Even if your meter can handle 20 amps, your test leads can not. You need to make up heavy gauge test leads or your testing will introduce a large voltage drop.

[hmcelraft]

The fans draw a lot of amps to start - if the fans cycle with the AC compressor it is drawing close to 20 amps with each start. The wiring is marginal too with the exposed grounds and mostly-exposed connections. Some folks have used stainless steel bolts and washers on the grounds which makes things worse because stainless doesn't conduct. So, clean connections are important and keeping the amp draw to a minimum is also important if you want to use the OEM wiring. A separate relay (30-40 amp rating each) and a separate circuit breaker (15 amp heavy duty rating each) for each fan is the way I have kept the heat down among, other things, including a fan sequencer and keeping the fans on all the time with the AC (no fan cycling with the AC clutch). I also changed the feed to the fans to come directly from the battery. It is a lot of stuff but properly working/reliable fans is a critical function.

[David T]

The fans draw a lot of amps to start - if the fans cycle with the AC compressor it is drawing close to 20 amps with each start. The wiring is marginal too with the exposed grounds and mostly-exposed connections. Some folks have used stainless steel bolts and washers on the grounds which makes things worse because stainless doesn't conduct. So, clean connections are important and keeping the amp draw to a minimum is also important if you want to use the OEM wiring. A separate relay (30-40 amp rating each) and a separate circuit breaker (15 amp heavy duty rating each) for each fan is the way I have kept the heat down among, other things, including a fan sequencer and keeping the fans on all the time with the AC (no fan cycling with the AC clutch). I also changed the feed to the fans to come directly from the battery. It is a lot of stuff but properly working/reliable fans is a critical function.

The fans MUST cycle. That keeps the duty cycle lower so the circuit can handle the power. You are right, if it cycles too often then you are defeating the purpose of cycling to reduce the total power required so although the fans must cycle, if they cycle too much that is no good either. As you also said, the whole circuit is marginal at best so everything must be in top operating condition to work. One of the best options is to switch to the newer, lower draw fans.

[dn010]

I wouldn't say stainless "doesn't" conduct, it just conducts rather poorly compared to other metals.

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[Bikercmbc]

Mine have burned up twice... had to just cut and solder new fuse holder in, purchase toby fans now and will purchase bitsync solid state fan relay to power them, and get rid of the fan fix that keeps the fans on constantly.

[papanoel]

I have the fan fix unit from hervey as well and its not working properly. I'm just getting new lower amp fans put it and removing that the fan fix from him.

[Beachdrifter]

Thanks all for the response and insight. Interesting posts. I will take a closer look at it this weekend, as I am away from the car. I guess I should have 2 fuse holders , not just one, but I will verify.

So why not just go with the original equipment the car was intended to have (pop in the original relays into the sockets) ? And remove the "fan fix" altogether?

I never questioned it until now ; it came with the car as it was installed by the previous owner like a decade ago.

-Randy

[dmc6960]

The fans MUST cycle. That keeps the duty cycle lower so the circuit can handle the power.

Please stop rehashing this over and over again. The fans to NOT need to cycle. The circuit IS designed for 100% duty. Keep your connections clean, tight, and ensure everything is at their proper rating. This includes checking each fan for over-current. A melting fuse has got to go.

[Beachdrifter]

Hi guys. So for those interested in the resolution of this, I ended up replacing the inline fuse holders and now the fuses run so much cooler. I can touch them. I am no electrical guru, but seems like the original holders were possibly not very good conductors and allowed for excessive heat build up. Everything is cool now and working great. If this happens to you replace with better quality fuse holders.

RANDY

[D Knight]

The best thing to do is get Dave's fan fail module. Well worth it. It also fuses both fans separately on the top of the unit. Plus it keeps the fan fail light working the way it should.


-D Knight-