Radiator fan motor connector=car stalling??

Discussion in 'Electrical & Stereo' started by mjstone, Jun 12, 2016.

  1. mjstone

    mjstone New Member

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    1998 GT, auto, 89500 miles.
    So, about a month ago my car overheated slightly while sitting in a parking lot. I was putting in some r134 to see if I could get the a/c compressor to stay on, turns out I had a leak at the low port valve. Anyway, while I was doing it the pressure seemed awfully high, so I walked around to turn the car off and coolant started coming out of the radiator.... I noticed in later that day that the fan wasn't coming on. After some troubleshooting, I pulled the connector and noticed some carbon/white charred stuff around the ground wire and the plastic surrounding it was a oblong instead of square(melted when got wet with hot coolant??). I cleaned it up a little with a safety pin, re-attached, and the fan worked, but jiggling the wire could cause the fan to stop, then start, etc. The car began stalling when going over bumps shortly after. If I had my foot off the gas and was going under 30mph over a couple hard bumps, it would stall out. With foot on gas, it would hesitate and want to stall, but wouldn't. The only way to restart the car was with starter fluid into the intake...
    1 week ago- Replaced the fuel pump and fixed the valve on the a/c low side. Car ran well.
    yesterday- had mechanic take car over some harder bumps to diagnose a metal on metal clunk in front end. Said its the motor mounts. Not a major concern for me, just curious. Other mechanic said the radiator fan didn't seem to be clicking on so he jiggled the wires. Ever since, I'm right back to the stalling issue and a/c going from warm to cold to warm, etc.
    This morning, I push in FUEL rail valve- zero pressure, nothing came out at all. I turn key, hear the fuel pump engage, test port again and there is fuel. Start the car, pull off vacuum to fuel pressure regulator, and watch for 5 minutes- NO fuel or smell, so regulator seems good. Next, I pull off the radiator connector again and really scrape away the carbon or whatever it is on that ground wire, then use computer repair tweezers to pull the copper out further and reshape it a little for better contact(ground wire ONLY). I reattach it. A/C works perfect, car drives perfect again.
    What the hell is going on with my car???? Can the radiator ground cause the CCRM to shut down the a/c and fuel pump? That is the only thing I can think of. I ordered a new motorcraft replacement radiator connector and will splice in on Wednesday.
    Thanks for any help- I am learning as I go along!

    Mike
     
  2. mcglsr2

    mcglsr2 Well-Known Member SN95 Supporter

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    Okay, so I have a 95, and my wiring info pertains to that. I'm not sure how close your 98 is to that, though I think it's pretty close.

    To me, it sounds like your issue is with the CCRM. The CCRM controls the fan, the A/C (specifically the A/C clutch control), and the fuel pump via a relay and some other stuff. It sounds like your fan connector is maybe shorting out, and it's screwing with the CCRM. Those fan wires go straight back to the CCRM, and if it's shoring out, it could be messing with the other stuff inside your CCRM (A/C, fuel pump, etc.). Best way I can think of to maybe isolate it is to disconnect the fan, run the car for a bit (like on a highway so you don't overheat) and see if you have any issues. If no issues, then connect fan back up, repeat. If you then have issues, my guess is the fan and/or connector is screwing with the CCRM.
     
  3. ttocs

    ttocs Legend

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    I was hoping someone with some experience in a similar situation would be able to help as I am not sure what to say. The fan is capable of pulling some current if it needed too and if a bearing is going out it could be causing a drag and increasing the current it needs to spin and causing a sag from the voltage. But this is all just a guess.....
     
  4. mjstone

    mjstone New Member

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    I haven't tried unplugging the fan, however I measured the fuel pressure. It was 32 at idle and cruising around, seemed fine. Stalled it over a bump with the gauge connected and it still read 32psi. Managed to start it that time without starter fluid, but it took quite a while. I replaced the pigtail connector at the fan by splicing in a motorcraft oem connector, so that seems to be working fine now. Tested the fan with a multimeter and it measured perfect. I even replaced the fuses in the box for the relay and the computer just in case. It will still stall over railroad track bumps or speed bumps(intermittently) if my foot is OFF the gas when going over- if my foot is ON the gas while going over railroad tracks, the engine will hesitate and RPMS will drop from like 2500 to 1500 with foot on gas.
    I went to the inertia switch in the trunk, banged on it and couldn't replicate the stalling.
    A local mechanic ran a diag and it came back with a "fuel pump short" and an "anti-theft" code, which was odd.... I'm ignoring the anti-theft code for now. Fuel pump still primes, car will run great over flat, paved, perfect roads- only bumps can duplicate the stalls.
    Where to go from here???