Logicon not working
06-12-12 | 03:34 PM
#1
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Joined: Feb 2011
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From: socal
Logicon not working
I had just swapped in a t2 motor in and everything is working fine, and the fuses are fine but the logicon doesn't work at all. It doesn't light up or do anything. I made sure everything was plugged in right too. I even swapped it out for a working one and it still doesn't do a thing. Anyone have any clues? Also, i was doing research on when all the idiot lights and shift light stay on and apparently it seems to be a bad alt, just wanted to make sure that's the problem before i go off and buy a new alt.
06-12-12 | 04:00 PM
#2
The Logicon is for the A/C heater controls, but the idiot light box is at the top of the dash. Is this what you mean? If so, then follow the directions below to check the idiot lights.
The lights turn on w/key to on and engine off or they turn on w/the engine running if the alternator is bad. Ground the White/Black wire at the alternator w/the key to on and the lights should turn on. If they don't then go to the CPU's largest plug and ground the Yellow/Blue w/key to on to force the lights to light up. If neither of these things work then disconnect the plug to the idiot lights and w/key to on check for voltage on the Black/Yellow wire.
The lights turn on w/key to on and engine off or they turn on w/the engine running if the alternator is bad. Ground the White/Black wire at the alternator w/the key to on and the lights should turn on. If they don't then go to the CPU's largest plug and ground the Yellow/Blue w/key to on to force the lights to light up. If neither of these things work then disconnect the plug to the idiot lights and w/key to on check for voltage on the Black/Yellow wire.
06-12-12 | 05:23 PM
#3
Thread Starter
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Joined: Feb 2011
Posts: 98
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From: socal
The Logicon is for the A/C heater controls, but the idiot light box is at the top of the dash. Is this what you mean? If so, then follow the directions below to check the idiot lights.
The lights turn on w/key to on and engine off or they turn on w/the engine running if the alternator is bad. Ground the White/Black wire at the alternator w/the key to on and the lights should turn on. If they don't then go to the CPU's largest plug and ground the Yellow/Blue w/key to on to force the lights to light up. If neither of these things work then disconnect the plug to the idiot lights and w/key to on check for voltage on the Black/Yellow wire.
The lights turn on w/key to on and engine off or they turn on w/the engine running if the alternator is bad. Ground the White/Black wire at the alternator w/the key to on and the lights should turn on. If they don't then go to the CPU's largest plug and ground the Yellow/Blue w/key to on to force the lights to light up. If neither of these things work then disconnect the plug to the idiot lights and w/key to on check for voltage on the Black/Yellow wire.
06-12-12 | 05:51 PM
#4
If the Alternator Warning Light Relay was stuck closed then it could lead to the idiot lights turning on as opposed to it just being an alternator problem, but in all probability the alternator is the likely cause. If you disconnected the plug from the alternator when the idiot lights are on do the idiot lights stay on or turn off. If they stay on then the relay is likely at fault or the W/B wire in the alternator plug is grounded out by accident. If they, the lights, stay on then disconnect the largest plug at the CPU which houses the W/B wire and w/the alternator plug disconnected as well you can perform a resistance test on the W/B wire to see if it is accidentally grounded or not. If the resistance is quite low then the relay is the cause. And when the alternator plug is unplugged when the lights are on and the lights turn off then the alternator is at fault.
06-12-12 | 06:51 PM
#5
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Joined: Feb 2011
Posts: 98
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From: socal
If the Alternator Warning Light Relay was stuck closed then it could lead to the idiot lights turning on as opposed to it just being an alternator problem, but in all probability the alternator is the likely cause. If you disconnected the plug from the alternator when the idiot lights are on do the idiot lights stay on or turn off. If they stay on then the relay is likely at fault or the W/B wire in the alternator plug is grounded out by accident. If they, the lights, stay on then disconnect the largest plug at the CPU which houses the W/B wire and w/the alternator plug disconnected as well you can perform a resistance test on the W/B wire to see if it is accidentally grounded or not. If the resistance is quite low then the relay is the cause. And when the alternator plug is unplugged when the lights are on and the lights turn off then the alternator is at fault.
