Can someone identify these wires?

[Bitsyncmaster]

So when I replace the holders use the mini fuse holders? Or are you saying still a standard sized blade fuse and "Little Fuse" is a brand name? Should I still use 20amp or maybe drop it to 15amp?

Little Fuse is the brand name of the fuses I recommend. Most auto parts stores sell BUSS name brand fuses. Does not mater if you use the standard or mini size. The fuse holders are what you get buying at the auto store. I would stick with 20 amp fuses which will run cooler than 15 amp fuses. The fuse is mostly just to protect from a short circuit. Fuses are not really quick enough to protect electronics or fan motors.

[David T]

Not sure what the purpose of those fuses are anyway. The original bypass that DMC offered did not include fuses and there is a circuit breaker ahead of the fuses. In any case the jumper was only supposed to be a short term solution till they could come up with a "permanent" fix! It makes me laugh to see that so many cars have been running on that stop-gap short term fix for so long! I guess it was a better long term fix than they expected. The Fanzilla was a great upgrade while it was available. If I had to do something now and couldn't get a Fanzilla I would replace the fans with newer, more efficient ones that take a WHOLE lot less power to run. Then you could probably put the blue fan fail relay back and it would not burn up.

[Bitsyncmaster]

Then you could probably put the blue fan fail relay back and it would not burn up.

I tested an OEM fan fail and to keep the fan fail light off would require 20 amps (10 amps each fan) current draw on the fans.

[Michael]

Got the holders replaced today. Used "Little Fuse" holders and fuses. I honestly don't know if both my fans were running before(never overheated) but they are both running now.

[Josh]

My radiator fans are just directly wired to the circuit breaker. Not sure the need of having in line fuses. Just gives another failure point in the system to prevent your fans from running and potentially overheating your engine.

It is also worth noting I ran a new 10 GA wire from the breaker to the fans and am running lower current fans.

[Bitsyncmaster]

My radiator fans are just directly wired to the circuit breaker. Not sure the need of having in line fuses. Just gives another failure point in the system to prevent your fans from running and potentially overheating your engine.

It is also worth noting I ran a new 10 GA wire from the breaker to the fans and am running lower current fans.

Fusing each fan protects the wiring better since the fuses are 20 amps each. With the 40 amp breaker the wiring is not so protected. Ether way if you get a dead short the fuse or breaker would open.

I removed the breaker. Like you say it's just another failure point. I send a jumper with my fan fail units to remove the breaker. That jumper (4 inches long) goes into the fan relay socket to the fan fail socket.

[David T]

I agree, the whole cooling fan electrical circuit could be a lot better designed. Two 20 amp circuit breakers or slow-blow fuses, one for each fan with a relay for each fan and a current sensing device to light a fan fail warning light and a delay so both relays don't energize at the same time. Very similar to what the Fanzilla tried to do. It's main limitation was that to be "plug and play", it had to install with minimal modifications so the breaker was retained. I don't like the breaker, not because it is too large to properly protect anything, it will reset itself and keep re energizing the circuit. If you do have a dead short you really don't want to do that except for the most critical circuits like headlights. Another way to go is a manually resettable circuit breaker but they are expensive and really not necessary. Just for the record, I have seen fan fail jumpers smoke and melt. And they had the 20 amp fuses in them! That's why I like the idea of upgrading to the lower amperage fan motors. Instead of trying to minimize the symptoms of a bad design (too much current draw in that circuit) you actually deal with the root cause of the problem.

[DMC-Ron]

An additional advantage of the fused fan fail jumpers is better redundancy. A short circuit in one of the cooling fan circuits will blow the fuse for that fan but the other cooling fan will still function. With only the breaker, it will continually reset and trip, leaving no cooling fan function. Of course with Dave's electronic fan fail relay you get the individual circuit protection along with the staggered start and fail notification, really the best of all worlds.

Ron