Fried electrical
Lead Driver
Joined: Mar 2010
Posts: 5,504
Likes: 256
From: Woodbridge, Ontario, CA
Battery junction box. Looks very similar to a fuse, except it's black and it has a diode symbol on it instead of an amperage rating.
Lead Driver
Joined: Mar 2010
Posts: 5,504
Likes: 256
From: Woodbridge, Ontario, CA
To test the diode properly, simply remove the diode and connect an ohm meter to the terminals. You should have continuity with the leads connected one way. Switch the leads around, and you should get an OL reading.
In other words, it allows current flow in one direction, but not the other.
In other words, it allows current flow in one direction, but not the other.
Hotshot
Joined: Jan 2004
Posts: 19,760
Likes: 1,079
From: St Louis
To test a diode with a meter, make sure you have one with a diode test setting.
In any event, simply look at your check engine light and turn the ignition switch to RUN. If the light comes on, the PCM is, at least powering up and there is no issue with the PCM diode. In any event, I've never seen a PCM diode go bad, even from crossed battery cables which is why it's there - prevents the PCM from getting reversed polarity power.
It's unlikely you'll find a diode in your local store anyway.
In any event, simply look at your check engine light and turn the ignition switch to RUN. If the light comes on, the PCM is, at least powering up and there is no issue with the PCM diode. In any event, I've never seen a PCM diode go bad, even from crossed battery cables which is why it's there - prevents the PCM from getting reversed polarity power.
It's unlikely you'll find a diode in your local store anyway.
Lead Driver
Joined: Mar 2010
Posts: 5,504
Likes: 256
From: Woodbridge, Ontario, CA
In any event, simply look at your check engine light and turn the ignition switch to RUN. If the light comes on, the PCM is, at least powering up and there is no issue with the PCM diode. In any event, I've never seen a PCM diode go bad, even from crossed battery cables which is why it's there - prevents the PCM from getting reversed polarity power.
It's unlikely you'll find a diode in your local store anyway.
It's unlikely you'll find a diode in your local store anyway.
For what it's worth, the PCM diode is located in fuse cavity number 37 of the battery junction box, adjacent to the A/C compressor clutch diode which is number 36.
Hotshot
Joined: Jan 2004
Posts: 19,760
Likes: 1,079
From: St Louis
For what it's worth, the PCM diode is located in fuse cavity number 37 of the battery junction box, adjacent to the A/C compressor clutch diode which is number 36.
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Freshman User
Joined: Feb 2017
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I appreciate the tips guys. I still haven't been able to test those diodes. I did notice the fuel pump is actually turning on now, before it would not. A new problem is it won't turn off. So now i suspect the pressure switch in the pump is damaged on top of the obvious other problems.
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Freshman User
Joined: Feb 2017
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I must have gremlins. I went out to turn the key to the on position to verify the check engine light came on. It did. How ever upon trying to crank the engine it wont crank now. It did this morning. Now i just hear a noise, something like a pop. Just once every time i turn the key. The odd part is i haven't made any changes since the last time i cranked the motor a few hours ago.
Hotshot
Joined: Jan 2004
Posts: 19,760
Likes: 1,079
From: St Louis
A new problem is it won't turn off. So now i suspect the pressure switch in the pump is damaged on top of the obvious other problems.
I just read up on the pressure regulator.
How ever upon trying to crank the engine it wont crank now.
I'd be looking at primary battery power and ground circuits followed by the starter circuit.
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Freshman User
Joined: Feb 2017
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Well i been slowly trying to narrow down my issues. All fuses have been replaced and the pcm was repaired by SIA electronics. It cranks but still no spark. The fuel pump wont shut off now unless i pull the relay. Any Ideas? I even sent the pcm back to be reevaluated and to make sure it is not the pcm. And the obd2 port still does not work. Could the power distribution box have been damaged?
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