Where is the IDM resistor located and were can I buy a replacement?
IDM resistor
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adsm08
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Idm?
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It shows on the 1988 electronic engine control(page#3 of 3) electrical diagram coming from or to terminal #4 on the EEC unit to the lead wire from the TFI to the coil(charging/starting diagram)There it shows the IDM resistor(Ignition Dianostic Monitor)
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The IDM resistor is a 22K ohm resistor that has been sealed in plastic in the original wire harness. The OEM part can just be replaced with a 1/8 watt 22k resistor from Radio shack and some heat shrink tubing. The reason for the resistor is to reduce the EMF voltage from the coil to protect the ECU input from the EMF spike. On some Fords that do not use the push start version of the TFI module the resistor is not used in the harness. It is internal to the ECU.
Thanks for the good info,I am having a possible problem with the distibutor(again) with the pick up failing.I 'll recheck all my wiring.What started this problem is I was checking the base timimg,pulled the sprout plug,and then it wouldn't restart after installing the sprout.And then after reseting the computer it fired up.The TFI is remoted to the inside of the cab so I don't think that's the issue,but will check.
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