Cooling Fan High Speed Relay BEC melted

[Corpo]

a relay costs $3.. and it wont happen again.

 

[Makdaddy]

With the AC is the fan governed to high by the PCM?
I was under the impression it would be auto set to high with AC on

 

[one eyed willy]

pretty sure A/C is low speed or maybe both, but i know when my fuse was blown to my high speed relay, the a/c would still still turn on my fan.

 

[Makdaddy]

pretty sure A/C is low speed or maybe both, but i know when my fuse was blown to my high speed relay, the a/c would still still turn on my fan.

willy that helps. I need to look for that fuse, its the high fan relay fuse?

 

[one eyed willy]

I have external relays with a fuse for both high and another fuse for low. The stock set up uses 1 fuse for both high and low. If your low speed works but your high speed does not, then I would say you have a melted connection in the BEC under the hood.

 

[Makdaddy]

I have external relays with a fuse for both high and another fuse for low. The stock set up uses 1 fuse for both high and low. If your low speed works but your high speed does not, then I would say you have a melted connection in the BEC under the hood.

cool I'll check that. I didn't know the fan would rn with the relay burnt

 

[one eyed willy]

cool I'll check that. I didn't know the fan would rn with the relay burnt

There is a relay for high and a relay for low. So it's possible for the low speed to still work while the high speed connection my fail or be intermittent at times depending on the condition of that connection in the BEC.

The 2 speeds are separate, so if the high speed relay burns up and the car kicks on the high speed, you will get no fan at all.

 

[Makdaddy]

There is a relay for high and a relay for low. So it's possible for the low speed to still work while the high speed connection my fail or be intermittent at times depending on the condition of that connection in the BEC.

The 2 speeds are separate, so if the high speed relay burns up and the car kicks on the high speed, you will get no fan at all.

That almost sounds too goof to be true
But I only had issues when I turned on the AC
I am sure i had the car parked and the AC on and the fans came on, but maybe just on low.
If i was in town and turned the ac off the temps would come back down
Its worth looking into
Thanks for pointing it out

 

[one eyed willy]

when its in low speed mode, the low speed wire is the only wire sending voltage. which is knocked down to 9 volts according to my volt meter at the resistor that attaches to the fan (where it plugs into the fan connections). when it goes into high speed mode, the low speed wire turns off and just the high speed sends power, now @ 12+ volts.

when my high speed fuse was blown (external something i added), my low speed still worked and my fans still would come on with the A/C, so i assume the A/C just turns the fans onto low speed, but it may kick it up to high speed if it gets too hot, that i did not test.

 

[eighty6gt]

Anyone know why the low speed circuit exists? NVH Concerns?

When my system wads up I'll do as others have done and just have the fan run at 12V with an aftermarket relay whenever it's commanded to be on.

 

[james432]

I had that happen too I found the hole thing at a salvage yard for 50 bucks and I was told my stock fan caused this put in a new fan too this was a few years ago..

 

[jbido]

a relay costs $3.. and it wont happen again.

Which relay?

 

[Corpo]

Which relay?

this kind of relay.

 

[Makdaddy]

4 post would be easier to wire
Fan instead of fuel pump and 30 amp fuse inline rather then 15
But the principle is the same . one feed out and one control wire

 

[Corpo]

Meh. The relays work the same. 4 post is just a little more dummy proof. That was just a quick Google search anyway.

 

[one eyed willy]

Defenetly need to use a 40 amp fuse.

 

[Makdaddy]

Meh. The relays work the same. 4 post is just a little more dummy proof. That was just a quick Google search anyway.

Its all good

Defenetly need to use a 40 amp fuse.

Most definitely
along with 10 or 12 gauge wire

 

[s8v4o]

On the back side of that connector, there is a 12 gauge green/violet wire. You need to cut and connect to a 40 amp relay. Run 10 gauge from your battery with a 40 amp fuse to your relay. Then cut and use the wire that comes from the computer that normally triggers the factory relay to trigger your new relay, I believe it is a smaller green/violet wire.

http://iihs.net/fsm/?dir=40&viewfile=Cooling Fan.pdf

Are the trigger wires also in the BEC or are they lumped into the harness somewhere?

 

[sportinawoody]

a relay costs $3.. and it wont happen again.

I misunderstood. I thought you were saying replace the stock relay.

 

[one eyed willy]

Are the trigger wires also in the BEC or are they lumped into the harness somewhere?

trigger wires go from the ECU to the BEC