lebaron dude
04-20-2011, 02:00 PM
On my '87 (power module + logic module) TBI LeBaron, I ran into a strange issue.
Initially, the engine would turn over but wouldn't catch (it was running fine the day before) I popped open the hood and everything looked like it was connected OK.
I put the key in the ON position, and rechecked under the hood and a few seconds later the radiator fan turned on. I thought this was strange because the engine was cold (the car hadn't been started in a day). I know the coolant-temperature sensor plug/wiring is old (and when the coolant-temperature sensor is disconnected the fan runs continuously) so I may check that out, but then the strangeness happened...
I turned the key briefly to the start position and was greeted with a click and then all the power went away. No door lights, no dash lights, no nothing.
I turned the key off and still no power what so ever in the car. Turned the key to the 'on' position, still nothing.
I disconnected the battery and then reconnected it. 'Ding ding ding' (door chime is letting me know that my key is in the ignition switch) and the door lights, dome light is working.
Turn key to start, all power goes away. Turn the key to off and still no power inside car (lights are off, etc). Turned the key back to on, nothing. Back to start, nothing.
Another disconnect of the battery, then a reconnect and the door chime starts ringing again.
So my best guess is that a transistor in the power module is shorted but only activated once you try to start?
Anyone else have this problem or think of a place to investigate? I have a power module on order but I don't want to drop it in and fry it, if there is something in the system that caused this (outside of old age... it's the original 87 power module).
I also swapped batteries from my turbo car and get the same behavior. I also didn't see or smell any magic smoke near the power-module when it first happened but... maybe it fried under the potting material.
Thanks if anyone can offer some insight.
Initially, the engine would turn over but wouldn't catch (it was running fine the day before) I popped open the hood and everything looked like it was connected OK.
I put the key in the ON position, and rechecked under the hood and a few seconds later the radiator fan turned on. I thought this was strange because the engine was cold (the car hadn't been started in a day). I know the coolant-temperature sensor plug/wiring is old (and when the coolant-temperature sensor is disconnected the fan runs continuously) so I may check that out, but then the strangeness happened...
I turned the key briefly to the start position and was greeted with a click and then all the power went away. No door lights, no dash lights, no nothing.
I turned the key off and still no power what so ever in the car. Turned the key to the 'on' position, still nothing.
I disconnected the battery and then reconnected it. 'Ding ding ding' (door chime is letting me know that my key is in the ignition switch) and the door lights, dome light is working.
Turn key to start, all power goes away. Turn the key to off and still no power inside car (lights are off, etc). Turned the key back to on, nothing. Back to start, nothing.
Another disconnect of the battery, then a reconnect and the door chime starts ringing again.
So my best guess is that a transistor in the power module is shorted but only activated once you try to start?
Anyone else have this problem or think of a place to investigate? I have a power module on order but I don't want to drop it in and fry it, if there is something in the system that caused this (outside of old age... it's the original 87 power module).
I also swapped batteries from my turbo car and get the same behavior. I also didn't see or smell any magic smoke near the power-module when it first happened but... maybe it fried under the potting material.
Thanks if anyone can offer some insight.