Good Battery No Power At All No Light Horn Nothing What Could It Be

alfonso331 said:

thanks yall its a 1990 lx 5.0 it has a good battery the car is getting no power at all but when touch the starter relay with skrew driver the engine turns over with no problem the not start thou cause car gettin no power

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jrichker said:

Go to | Repair Guides | AutoZone.com. Enter the year model and other info to get to the vehicle repair guide. Post a diagram or link to the the alternaor electical diagram and I will try to help you.


Get out your DVM or multimeter because you are going to get to do some
voltage checks.
The voltage regulator has 3 wires according to the above diagram.
1.) The black/orange wire is the alternator power feed to the car and should always have 12 volts or more
2.) The yellow/white wire is the power to the regulator and should always have 12 volts or more
3.) Lt green/red wire is the switched power to the regulator and will have 12 volts or more any time the ignition switch is in the Run position.
4.) The White/black wire coming from the voltage regulator will have a variable voltage on it any time the ignition switch is in the Run position. As the battery gets closer to full charge, this voltage will decrease. I would expect that with a low battery, this wire would have the full battery voltage on it.
5.) Notice the fusible link – you should see 12 volts or more on both sides of the link. If you find 12 volts on one side but not the other, the fusible link has burned open.

The one thing that I do not understand about this diagram is the connection between the white/black wire on the alternator to the choke heater. It may be a sneaky way to turn the choke heater off as the engine warms up. However, I would use the DVM or multimeter to confirm resistance between the white/black wire going to it and ground. I would expect to see less than 100 ohms here.


Alternately, here is another solution - a 3G conversion.

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