High speed fan relay keeps blowing need help

[JeremyH]

Stick with the stock tstat then.

 

[james432]

So far so good drove around all night and still works hopefully it was the fan I replace fri night..I'm go

 

[michael.konor]

...These motors like to be at around 180-190 degrees to run good. I forced it cooler for awhile and had misfires and gas mileage goes down quite a bit.

You're not kidding about that. My gas mileage dropped like a rock with the colder thermostat and lower fan settings. Went back to stock thermostat and 10% lower on the fan settings and it's been good since.

 

[james432]

Looked up the BEC block but only found the fuse block under ford parts is that it

 

[james432]

Took it apart check this out great now what

 

[michael.konor]

^^^ That would do it...

As for what to do about it, you've got a couple options:

1. Buy an entirely new expensive wiring harness (not best option).

2a. Find someone with a junk wiring harness, harvest the block, and working *slowly* and *carefully*, move the good wires wires over one at a time. (Better option)
2b. Use the junk wiring harness to harvest the damaged wires, remove the damaged wires, match the replacements by gauge, and **solder** in the new ones, use heat shrink to seal. Don't crimp or use electrical tape.

The good think about Option #2 is that you're not limited to using a Ford Mustang Harness, but any Ford Harness with the same block. Also, check salvage yards since it don't need a serviceable harness. Only one with one block that you can harvest.

 

[james432]

Well my friend works on cars at a ford dealship and he has a v8 ranger he said he can mount a relay outside is the fuse box and bypass it..he told me just to go by a relay today what size relay do I need I forgot to ask him lol..

 

[JeremyH]

A standard automotive relay will work 30/40 amp.

 

[james432]

Okay cool..he never showed up has anyone done this before so I make sure I have the right wires and stuff thanka

 

[james432]

Okay I got a new fuse box and wire Barnes is back to stock but the high speed fan relay is getting hot when the fan runs still any one have any ideas?i put in a new 180 t-stat set fan low 190 high 200 and new fan stock and new three core rad..I don't no if that normal dose ur guys fan relay get hot when its running for awhile??

 

[michael.konor]

How hot? Hot enough that it burns to touch the relay?

Heat building up beyond what may be the norm in a relay is caused by restriction. I've no idea how hot is hot, never raised my hood to feel my relays.

If your fan is pulling too many amps for the circuit to handle, heat builts, and parts melt. Burnt wires and melted connectors are the symptoms --> result, not the cause of the initial problem 95% of the time.

I looked back through the thread and don't see where you replaced and/or checked the fan.

 

[james432]

I replaced the fan it's brand new it just seems to run alot

 

[james432]

This all started when I put the three core rad in..put in a new fan and everything only thing I haven't repaced would be the coolent sencer on the inside of the pass head don't no if that would be the problem but like I said the fan seem to be on alot..

 

[james432]

Okay we ran a amp test its putting out 33 amps is that fine on the high speed