Mechanics

RELAY CONTROL MODULE

1994 Ford F-150 • V8 4WD Automatic • 125,000 miles

1994 f-150 5.0 L, 4x4. My speedo, odometer, went out and my auto transmission started******** hard when shifting into higher gear. I had the same problem 3 years ago and I changed a blown fuse (position 18) and it worked fine.
The same problem showed up 6 months ago, but this time the fuse was not blown. I took it to a mechanic who replaced (he said) the relay control module ( part #F6DF-12B577-AA). Does this sound right, and how do I find the location of the module on the truck and how easy is the repair myself if I get the part? Thank you
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Salgar444
July 7, 2011.




The part number is for a CCRM (Constant Control Relay Module) but I don't believe the F150 even has one and the cars that did, it housed the A/C relay, cooling fan relay and fuel pump relay, all of which this truck has individually.

Wrenchtech
Jul 7, 2011.
OK. So how would I go about trying to find out what the problem is?

Tiny
Salgar444
Jul 7, 2011.
Sounds like an issue with the Vehicle Speed Sensor but it needs to be diagnosed properly.

Wrenchtech
Jul 7, 2011.
I understand you want to troubleshoot the VSS. You will need a lab scope for that.
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Wrenchtech
Jul 8, 2011.

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