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I'm running out of ideas so I figure I'd post this up, hoping for some electrical knowledge here.
Last week I was driving my LS1-swapped Chevelle, troubleshooting some drive-line vibrations and I noticed my coolant temps were high.
Running the Ford Contour Dual fan setup, each fan has it's own relay and 30 amp breaker.
PCM program:
Fan 1 comes on at 193 F
Fan 2 comes on at 200 F
Got back to house and temp was around 210-215, noticed neither fan was running.
Fan 1 with 30 amp breaker had popped. Fan was seized up, motor went out.
Fan 2 breaker was closed.
So I replaced fan 1 motor and thought the fan 2 breaker was maybe bad so I replaced it.
Now Fan 2 still won't come on, fan 1 will come on, then shut off, then pop breaker when it tries to come back on.
Here are my known facts:
Both fan motors are good, and run when hooked directly to 12v power.
Both Relays are functioning, swapped with unused new ones to check.
Both fans have a confirmed constant 12v hot, (set up for PCM to send ground signal to close circuit.)
Fan 2 isn't getting a closed circuit to turn on when put a meter on the connection (PCM not sending?)
I can't think of anything I've changed that would cause this new issue. Is new Fan 1 motor now drawing more amps than the old motor? Do I need a higher amp breaker?
I'm thinking my wire size may need to step up to maybe a 10 or 8 gauge?
It's very hard to troubleshoot without seeing exactly how you have it wired. First thing I would test is to ground each relay coil and see if the fans kick on and operate correctly. If they do then you know your not getting a good ground from the PCM.
This is the schematic I'm running more or less. Set up where fans have constant 12v and pcm sends ground signal to operate relay, then sending ground to close circuit.
When I use a jumper across 30 and 87 posts on relay, fan 2 comes on.
Any reason why pcm would suddenly not be sending signal for fan 2?
I picked up some 8 gauge wire on the way home from work thinking that may help my fan 1 amp problem....
Getting in on this a bit late..........
I'm thinking my wire size may need to step up to maybe a 10 or 8 gauge?"
So, what do you have now?
Where are the fans grounded?
A 30 A draw on a fan will show a surge well over it's normal op draw.
Just checked back in on this. Actually the culprit on this was some of my wire connections coming loose at the breaker.
Also for fan 2, I made a wiring mistake at the relay, which I corrected. All seems to be working good now. (Except for my AC issue! See other post, lol)
07-07-2016, 03:25 PM
E-fans tripping breaker/not running 
