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Short to ground caused by blown 02 heater circuit? - 2000 Dodge Ram 5.9L
Hey all, I've been tracing misfires and strange behavior on this van for some time now and I'm attempting to narrow in on faulty wiring - looking for some advice to see if I'm on the right track.
Recently I found what seems to be a short between battery positive to the engine ground.
Also I'm reading battery voltage between battery negative to engine block (with battery negative detached and battery positive attached).
I've traced it to my 02 heater circuit with some help from a Mitchell wiring diagram. These are NTKs which are known to be good for picky Chryslers.
Basically, I'm reading 2.6 Ω across the ASD circuit (coil, 02 heaters, injectors) power to ground (ground wire to block detached) with both of the 02's plugged in. When 02s are removed, OL. (These readings are with PCM and battery completely unplugged.)
I'm assuming that resistance will go up when they get heated but having such low resistance to begin seems pretty much like an open which could be the cause of my issues and why I'm reading battery voltage at the block. Also, the ground side of the 02 heater circuit meets the PCM ground on the same bolt on the block.
What should resistance on heater circuit be on a Chrysler 5.9L setup 02? (It seems like most others should read around 10-20Ω)
What causes blown 02 heater circuits?
2.6 ohms for two O2 heaters in parallel is believable. Works out to 5.2 ohms each.
I wouldn't worry about measuring battery voltage on the block with the ground lead disconnected either unless your battery is going dead within days. Probably the PCM key off memory circuit.
So what is this "strange behavior" the van has been doing?
