QuestionQUESTION: Add fuse keeps blowing. Mechanics says no power to ecumenical but he isats Edmund and pcm are same thing. Tried to start after charging battery and it turned over 4-5 times. After 5 minutes it would only turn over 2-3 times and 5 minutes later starter would not even turn over. If I unplug pin connector on pcm it no longer blows fuses
ANSWER: Hi Carl
Please describe exactly which fuse is blowing and if it is in the powerbox in the engine compartment or in the box behind the left end-cover of the dash. You need charge the battery again, but first we have to figure out which fuse is blowing and why.
Roland
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QUESTION: ASD fuse under hood. It is fuse #5. I replaced battery as it was showing
Marginal. Can you tell me where he ASD relay located? ?
ANSWER: The ASD is in the back section of the powerbox where you found fuse 5 to be blown. I doubt the issue is the relay itself but rather one of the many devices that is sends current to that is supplied by the fuse. Specifically I would check the oxygen sensor mounted on the front exhaust manifold as it has fragile wires which can break and be shorted to ground. Similarly check the downstream sensor on the far side of the catalytic converter. The dark green/orange wire is the one that carries the current to all the devices. It also goes to the distributor, the fuel injectors, the alternator, and the egr transducer. So somewhere in that distribution you will find a short to ground, I believe.
The ASD relay is the front/inboard relay in that rear section, and the output pin is the outboard-most pin. I would believe you will find that pin is shorted to ground if you pull the relay out of the socket, and your problem will be solved when it is no longer an absolute short to ground as measured in ohms.
Roland
Roland
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QUESTION: If I unplug the 2 connectors from pcm ( outboard side of fuse box) the fuse no longer
blows. I plug in rear connector and everything is fine. When I plug in the front connector
The fuse blows. I believe both of these connectors have about 40 pins in each one.
AnswerHi Carl,
While inferring what is shorting based upon a plug with 40 pins (22 wires) is imprecise, the more likely items are: generator field coil/oxygen sensor upstream/egr. The other items are sensors or have a coil in series (fuel injector driver/ignition coil driver). So see if the generator field coil wire's pin or wire (dark green/orange) shows a dead short to ground, similarly the oxygen sensor (dark green/orange). That narrows your search.
But to differentiate between a short and a normal coil you will need a digital ohmmeter so that you can tell the difference between near 0 ohms and maybe 2 ohms (which would be expected but would not blow the fuse). Please let me know.
Roland
