So we've got a nice hot day and my A/C starts blowing warm air...

I get home and sure enough, the electric fan isn't on (even though the engine is hot)

If I turn on the fan switch, It will stay on for about 2 minutes then the circuit breaker will trip, 5 minutes for the breaker to cool off and the fan starts up again.

The A/C temp circuit is the same (stops because the breaker trips)

Here's what I know, anyone have any ideas?

Battery Post->end fan harness 2.1 Ohm
Starter Post->end fan harness 1.0 Ohm

no cross conduction (all wires are seperate)

I had this problem about a month ago and replaced the fan motor, but today was the first day I've had that was hot and I was in traffic...

HELP!
Coldie

 

well its either the motor or some faulty wiring.

i'd say call up who ever you bought it from and get the whole thing replaced.

but first completely uninstall it and then reinstall it. could just be a wire not connecting

 

a bad relay heating up and poping the fuse

 

The weird thing is, both the temp/AC fuse and the switch fuse are kicking in.

The temp/AC relay kicks on correctly then the breaker will kill it. If I hit the switch, the breaker (completely sperate) will kill it. These are two completely different circuits into the motor, and yet the same problem.

I'd say it was the motor, but what are the chances of getting two bad motors in a row???

Coldie

 

i have no clue, if you want come down to my place sunday after 3pm and we'll stick my fan in your truck.

 

I bet it is in the wiring. I have had electric fans in all my cars and trucks for the last 20+ years and never had a fan motor burn out. Wiring, relays, thermal switches, controllers, fuses...yes, all of those have gone at one time or another, but not the fan motor. Maybe I have just been lucky.
Chris S.

 

it's kind of hard to get the picture of what your saying, but if you have two seperate breakers that are both tripping independantly then check for what's common to both circuits. If the fan motor is the only thing common to both circuits then I would suspect the motor. I'm curious as to why you would have two circuits for the same device (fan motor). Switches and relays add no load to a circuit so they could have been fed from the original source (hence only one fuse).

 

I the fan on the same circuit as the AC? If it is, there is way too much current draw.

Did you isolate the fan with a relay and it's own circuit breaker?You should be using the AC circuit to operate the relay only. The fan should be running off of the battery.

 

This is JDM's fan kit.

The fan wiring:

temp sensor and AC power sensor go into two relays. These relays connect the battery (straight off the battery) to a circuit breaker directly to the fan's low power wire (fan is two speed).

fan ground is connected directly to battery.

The other circuit is simply battery->switch->circuit breaker->fan high speed power

The two circuits are completely independant of each other.

My only though is that the fan motor is getting hot and drawing slightly to much current. Hence the it only happening on hot days...

I'm thinking about just bumping up the circuit breakers a bit(they are 30/40 make them 40/50) and seeing if everything turns out OK.

Coldie

 

Wouldn't it be a good idea to call JDM and ask them for a possible cure for your E-fan, after all it's their unit and I'm sure they would help you zero in on the problem. I've had their fan on my 2000 L for over a year now with 0 problems, but anything can happen. Jim and his gang is participating in a Fun Ford Weekend event but will be back at his shop Tues. Give him a ring, can't hurt, might help, John H.

 

Well theyve already replaced the fan motor, so I figured I'm ask the board over the (HOT) weekend. The fan is now hooked up and running great through the 40A breaker.

My best guess so far: The stainless steel headers are generating enough heat that the fan motor is getting hot and drawing to much load by just a bit...

Coldie

 

I looked at ciruit breakers for a similar application. Their performance is greatly influenced by ambient temperature. I would try swaping out the breaker for a 40amp fuse. Use a "Maxi" style fuse, these are much bigger than the standard ATO blade fuse. You can find it at Schuck's, about $8 for the fuse holder and $4 for the fuse.

 

It appears that it is the temperature under the hood causing problems. This all started when the Stainless Steel headers went on. (BIG heat source).

It's one of two things:

1) motor is heating up pulling more current
2) circuit breakers (located directly above headers) are heating up and tripping.

The circuit breakers were very hot to the touch (say 120 or so, almost burning), so I'm inclined to believe it is them.

I connected to the 40A breaker and everything is great, so it looks like I'll either go with coolers idea of real fuses or just get a bigger breaker.

I may add a bit of heat shielding to the break cover to make things easier.

Coldie

 

Coldie

Maybee you can relocate the breakers to a place where the headers won't effect them as much. Maybee you can even get them up under the dash so they will stay nice and cooool

 

Like Don said. Put the circuit breakers and relays in some cool air flow.