Electrical Fan Spins Intermittently

Discussion in '1994 - 1995 Specific Tech' started by JordanB21, Oct 4, 2012.

  1. I could test them both at the same time and look for similarity (pins 6 and 7, right?) and the fan's connector.
    But, yes we don't know why they're different. And there's defiantly no CB, I looked up images to compare and be sure, you were right, it would've been very obvious.
  2. I would want to resolve that before doing anything else. There's no reason for a voltage drop like that unless the wiring is compromised.
  3. They came out pretty together this time, I'm guessing they only varied because of the battery's voltage varied during each separate time I took voltage. I don't have an erratic idle, the volts just rest anywhere from 13.5 to 14.5 usually.

    Anyways, the readings and wires must be good, I took them all within a minute of each other
    Battery voltage: 14.42
    Fan connector:14.11
    Pin 6: 14.38
    Pin 7:14.38
  4. Gotcha - that looks good. But the fan motor doesn't spin? If not, as you know, it's swap time. I'd try to remove the motor before even buying a new motor (if you have another car to go get a new fan motor) because as you saw on the other thread, sometimes the shaft seizes to the fan-blade hub. In such a case, a new fan assembly is probably needed.
  5. The only one thing that makes me question the fan motor seizing or going bad is that when I ran jumpers it spins.

    I'd happily toss down the 65 for a new assembly and motor if it solved the problem, I just want to be sure that's the problem before I do (though I might have to anyway).
  6. How was the bench testing done? Did the fan come right to life or did it seem to really bog and take a bit to get going? The initial draw should be 60-100 amps for a fraction of a second.If it hems and haws or makes weird noises as it powers up, that's a tell.

    If you have a wiring issue, it could inhibit the current passage (but show full potential [Voltage]). You're the only one there to make the call.
  7. It was using two 12 gauge pieces of wire directly to and from the negative and postive battery terminals on a standard 12v battery going to the ground pin and high or low pin on the fan. It didn't appear to bog, i'll test again and look for bogging.

    if the passage was inhibited but showing voltage it's preventing enough amps to power it?

    Also, I don't know if this is noteworthy or not. But as the title says it spun intermittenly. But now it hasn't spun since oh say my 2nd post where I noted it did on october 4th. It hasn't reacted to temperature or max a/c since then.
  8. That's putting the issue back to the CCRM or compromised wiring if the fan spins okay by jumping the connector.
  9. Even though there's voltage at the fan connector the CCRM could be at fault? Afterall there's only voltage to the high when the max a/c is on, not both pins, so some function of designating which speed is working.
  10. So does it pass a bench test now?

    For overall testing to be relatively valid, the fan has to not spin up under CCRM control but then immediately pass a bench test.

    I think you know, but just in case, only the high-speed terminal is hot with the AC on (I mention it because some fans energize both speeds on high). Said another way, the middle terminal being cold with the AC on is expected.

    If you had a compromised wire, it would have probably burned up by now. I've gotten pretty confused trying to follow this thread (which is why I ask for re-hashes sometimes).

    Do you have any spare fans around (for other cars)? I'd almost wanna rig up jumpers and see if the CCRM (via the stock fan connector and some jumpers) can power a spare fan. If it powers up a spare but not your fan, that's telling.
  11. I know when I was testing my fan circuits there were times when both high and low leads going to the fan were hot!
  12. I still need to do it later today (have homework to do first-___-), and okay to the second part for how it should work. d:
    Yeah, I figured this, the low speed fan is 'cold' in a sense, it still puts out volts when the high should be on but it only puts .30 volts to .50.
    well. I could run from X pins (whichever pins are meant to goto directly to them fan) to the fan and ground it out aswell to see if fresh wires get it to spin through the ccrm?
    If it does spin through the CCRM w/fresh wires we'd know the fan and CCRM is good but wires are compromised, if it does not spin through the CCRM then either the CCRM or fan motor is bad, which would point more so to the fan motor Ithink since we got 12volts when it was suppose to be on on the outputs of the CCRM and at the fan connector. I think that sounds right...?
    This sounds pretty easy. I could go pull another fan from another car (the ones im allowed to touch in the family are both clutch fans:/). The salavage yard is pretty stripped but I 'might' be able to find one. It's fortunately down the road, but I just need to find the time to get there and do it.

    I'll feel for the resistance when I let it run next time.

    Really, thank you both for following me even this far, a month out!
  13. You could but it would be tough to make a solid connection capable of carrying that much current. You'd almost have to cut and solder new wires on even to do the test. THe chances of the wires being compromised are not likely, esp if your recent testing shows the same voltage at 6/7 and the fan connector. You could wiggle test the wiring harness and fan connector while the fan is on to see if you can get it to shut off or do something funky.

    I would rather do a bunch more bench tests to see if the thing will fail. Without an ammeter, it's tough to make deductions. It's more likely that the fan motor is bad. If you plan to keep the car for another summer, I'd almost say to just replace the fan motor. It might not fix your issue but it sounds like the fan motor is resistive, so you'd replace it at some point anyhow (the motors are, or used to be at least, lifetime warranty). There are not any safe methods of testing the fan motor that are also simple (to test start-up draw, and thus infer resistance, requires some equipment).

    I wouldn't go to all that trouble. I thought maybe you had a spare fan sitting around.

    Really, thank you both for following me even this far, a month out![/quote]
  14. Were you having fan control issues? You can apply 12V to pin 14 and ground 17 at the same time, but it's not good for the fan motor. I imagine you did not have both triggers energized, so that was not good.
  15. Well the salvage yard is easy to do, I went down there today to drop off the CCRMs he let me borrow for testing. I took a look at a bunch of ford cars too, there was a ford tarus with dual fans out there and the connector looks like the same kind on sn95s so i'll get that wednesday and hook it up and test it and see if it spins.

    It's really no problem, since I have to go back out there and pull horns for my Fox too.

    Also I might try this then, if the fan motor is going out, then it wouldn't matter too much to me if it wasn't good for it.

  16. Yes I was until I installed a new relay into the CCRM. Since the fan is working properly now I haven't tested the wires again.
  17. That was actually directed at Mark's comment.
  18. I know, but further testing is all the same, just another idea to throw at the car.
  19. Picked up a new used fan today from the Tarus and plugged it in, no spin. Changed the CCRM with another one (code J, different code but very similar parts number), car started, no spin.

    I also tried with both the test fan and the stock fan to ground at pin 17 and apply 12v at pin 14, no movement.
    How likely is compromised wires? What's left, if anything, to test?
  20. When you ground out # 17 did you check for output signal from the CCRM high speed fan circuit?