Compression Ignition Addict
Join Date: Aug 2008
Location: Madison, WI
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Measure the voltage _drop_ across the contact terminals of the relay. Turn the key to run, and do either (or both) of the following:
* Measure the voltage _between_ the two big terminals. Put the red probe on the "always hot" terminal. That voltage should be less than 0.3V.
* Measure the voltage (to ground) at each of the big terminals. The difference between the two is the voltage drop, and again, should be less than 0.3V.
Might want to do this on both relays. In either case, if the voltage drop exceeds 0.3V, it won't provide sufficient voltage to the plugs.
The PCM is actually what grounds the coil circuit. You should have 12V at the red/green wire when you turn the key to RUN, and the orange wire (orange? well, the one that's not red/green...) should have continuity to ground, until the PCM cycles off.