LostnFound Posted October 9, 2012 Share Posted October 9, 2012 I changed my cluster circuit board today. The good news is that all the lights are working again and the fuel gauge is working again (fuel gauge and generator light hadn't worked since I damaged the circuit board when I replaced the headlight switch). The bad news is that the generator light won't go out. I've had a charging problem for a while now and hoped that replacing the circuit board would fix the problem. It is only getting 12.5 at the battery and should be getting 13.5+ so I have been told. Let's see....new battery, had the alternator rebuilt, replaced the voltage regulator, new headlight switch and new circuit board. Anyone have any suggestions? Thanks, Larry Quote Link to comment Share on other sites More sharing options...
LS5 Posted October 9, 2012 Share Posted October 9, 2012 Hey Larry, does the Negative Battery cable have a secondary wire coming off the battery clamp and grounding out on the fender and where is the ground battery cable going to ?? The block or alternator bracket or the frame ??? and have you checked your Fuseable links lately ???? How many amps is that Alternator rated for ??? Darren. Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted October 9, 2012 Share Posted October 9, 2012 12.5 isnt really enough, thats what I had and the gen light was on I replaced the alt the light went off and had 14 volts at battery at fast idle. I did have to replace the battery afterwards also but it was 5 years old. Quote Link to comment Share on other sites More sharing options...
John Burns Posted October 9, 2012 Share Posted October 9, 2012 Larry- check this site out. It might help you find your issue: http://www.madelectrical.com/ Quote Link to comment Share on other sites More sharing options...
LostnFound Posted October 9, 2012 Author Share Posted October 9, 2012 Thanks guys ....Update...I ran it over to my mechanic this morning. It is now charging at 14+ so all is well now in the charging dept. Replacing the circuit board worked. Darren....yes, there's a secondary ground wire coming off the battery clamp and it goes to the fender. The ground battery cable goes to the alternator bracket. I was told that the Alternator is rated for 80 amps. Now I need to get to the bottom of the idiot light issue. When you turn the ignition to on but not start, the idiot lights are suppose to light up and mine are not. Then, after starting the car, I have a soft generator light on all the time even though the system is charging fine now. Any ideas/suggestions would be appreciated. Thanks, Larry Quote Link to comment Share on other sites More sharing options...
Mo's70MCs Posted October 9, 2012 Share Posted October 9, 2012 Thanks guys I have a soft generator light on all the time even though the system is charging fine now. I'm sure you mean "Alt" though that's not important, does it go away when you rev the engine? Usually it stems from low RPMs..loose V-belt or worn. I doubt that's the cause, but inherently a dim light maybe related to the diode trio in the alternator. Re-builders hardly ever replace the trio? Quote Link to comment Share on other sites More sharing options...
LostnFound Posted October 9, 2012 Author Share Posted October 9, 2012 Hmmmm....it doesn't go away when engine is revved. The belts are new and tight. I'll mention the diode trio to my mechanic though. Thanks Rod. Cheers, Larry Quote Link to comment Share on other sites More sharing options...
bigtankjones Posted October 10, 2012 Share Posted October 10, 2012 If your still using the external regulated alt. Check your connections at the regulator. I switched to the internally regulated alt and bypassed those connections myself instead of buying the kit from OPGI. I had issues with my gen light staying on but dim to. Then got rid of the orig setup and switched it over. No more gen light staying on. Comes on when I turn on the key then goes out when started. Quote Link to comment Share on other sites More sharing options...
LostnFound Posted October 10, 2012 Author Share Posted October 10, 2012 Thanks Tony. That's a very good point. My mechanic was saying the same thing and said he may change the connectors in the voltage regulator plug. I've already changed the voltage regulator and he suspects that it may be the connector> I'm trying to keep the car as original as possible so I'll try to repair the existing system first. Thanks for the valuable input Tony and thanks for the wiring diagram Mike. The members of this club rock. Having my late Uncle's Monte is great but you guys make it even better. You guys are the icing on the cake. Cheers, Larry Quote Link to comment Share on other sites More sharing options...
cbolt Posted October 11, 2012 Share Posted October 11, 2012 I have seen more than one faulty external regulators when they are brand new. I second the recommendation to switch to the internally regulated setup. The swap is fairly inexpensive, simple, and reliable. Quote Link to comment Share on other sites More sharing options...
stangeba Posted October 11, 2012 Share Posted October 11, 2012 I had a melted connection at the voltage regulator once. I also had a loose Instrument Cluster (Gauge type) plug after I re-installed the dash after a heater core replacement. Just needed to plug it in better and it started charging. Quote Link to comment Share on other sites More sharing options...
MGD72Monte Posted October 12, 2012 Share Posted October 12, 2012 Larry, Congrats on achieving some progress. I had a soft gen light after I damaged the flexible circuit board of my cluster, some of it melted after I got a short so the whole side of the cluster had issues. There is likely an issue with the gen light circuit such that it is grounded somewhere. Hard to troubleshoot at a distance but I would be looking at that circuit. Good luck Quote Link to comment Share on other sites More sharing options...
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