7A Radiator Fan - Fuse vs Circuit Breaker

[cgharibo]

I have a 16" puller Spal fan installed on my 7A that works well. The stock wiring triggers a relay that draws power directly from the alternator which is protected by a 40 amp fuse.

Every few years the inline 40A fuse and its holder, usually in the summer months, just melts without blowing the fuse. Although protected from the weather, corrosion and poor contacts that generate heat are the likely culprits.

How do I prevent this meltdown? I am considering substituting the inline fuse holder with a 40A circuit breaker or a fuse box or any other suggestion.

What is the most robust option for this fuse so that its holder doesnt meltdown?

Thank you for your suggestions.

[newsh]

Bolt-in fuse?

[cgharibo]

How about an automatic or manual reset 40A circuit breaker?

[Lago Blue]

Chris,

Please say what type, make and country of origin, of current fuse and holder; and what gauge wire was used.

[cgharibo]

Lago Blue,

I had a 40A ATC fuse, 16 gauge wire, made in china fuse and holder. The connections were secure and I had dielectric fuse applied.

The set up survived well until this summer when the fuse and the holder melted without blowing.

What's the best solution to get rid of the heat at the fuse. There are the ANM fuses above and also larger ATC type fuses.

[Lago Blue]

I read that some 16" Spal's require a 50 amp fuse, however as your 40 is not being blown, that may not be the case here.

Similarly, I don't believe another fuse type or C/B of 40A capacity will stop the heating issue either.

It may be that the fuse holder does not grip both blades of the fuse sufficiently.

From the rennlist.com (a Porsche board), I read some "Chinese no brand name ATC fuses are often made with poor fuse accuracy, poor materials/plating (including the plastic compounds) and even incorrect blade thickness/dimensions - these fuses cause problems (heating) due to poor connections and may damage the fuse-holders permanently"

Some folks take care to use only U.S. Co. made fuses (i.e.: Bussman, or Littlefuse (link below)) and holders.

https://www.littelfuse.com/products/...e-holders.aspx

Could it be also, that the wire gauge is too narrow for the amp draw and wire length? See article and chart here:

https://www.offroaders.com/technical...gauge-to-amps/

[Tom_]

cgharibo Do you use the stock 7A fan shroud or some custom? Do you keep the stock wiring?

[cgharibo]

Tom, I have the 16" Spal puller connected right against the battery without a shroud. It works fine.

I eliminated the low speed resistor so that the Spal always gets 12V. The wiring to the relay is stock and the rest is wiring from a Spal fan wiring kit. The fuse and all the relays are in front of the condenser.

JUST TODAY, I was tinkering with the 7A and noticed the T connector between the fan relay and the fan is showing signs of burning at the + wire AND the insulation on the + wiring is all cracked! WTF!

Something is a miss. This fan is becoming a maintenance item for me!