Hello All,

Thanks in advance for any help you may be able to offer. I recently installed a battery in a 1973 Omega. Here's the bonehead move: the battery that came out had reversed terminals (converted from side post to top post, by the way) versus the battery I put in. You know where this is headed, right?

I connected the cables backward for a moment before I realized what I'd done. There was a spark, naturally. There also was a little puff of smoke that came from the starter area. I immediately removed the negative cable and checked the fuses. None were blown.

I reattached the cables (correctly this time) and started the car. The car starts and runs fine, except now the GEN light stays on, even with the key in the off position. If the key is in the ACC position, it goes out. The GEN light also stays on in the RUN position.

I checked voltage at the battery with the engine running; it's about 13.7v, so the alternator appears to be working.

What did I fry? Regulator? Diode? The whole alternator? Any ideas?

 

Diodes

 

IDK what broke but if the diodes were fried IDT you would get 13.7v at the battery w the car running.

 

There's a fusible link down at the battery. Look for a brown wire that changes to red on the body side of the fuse link. Another fuse link is in the main harness at the horn relay and junction block. Look for a black wire

If it's a 6-cylinder car there's also a fuse link in the smaller red wire to the alternator.

The way I read the wiring diagram if the main harness fuse link(s) is burnt, there shouldn't be any power anywhere in the car except the coil. If only the alternator fuse link is burnt, you'd still have 12V to the alternator field and rectifier.

I'd have the alternator tested first. If it shows good, then it's time to dig into wiring.

 

If only one diode opened up, there are more to take up the slack. However rather than a full wave rectifier, you could be down to a half wave or somewhere in between. DC volts on a voltmeter will still look 'good'. The diodes can be replaced easily in a stock alternator. Have the alt checked for sure.

 

x2

 

Thanks for the info. It's a 6 cylinder; sorry for not specifying that. I will check the fusible links you spoke of and get the alt tested next.