UncleJ Posted December 18, 2011 Share Posted December 18, 2011 Alternator wasn't feeding my battery and my battery kept draining. Swapped out my alternator and it's still having the same problem. Connections are good. Any ideas? Quote Link to comment Share on other sites More sharing options...
Leghome Posted December 18, 2011 Share Posted December 18, 2011 regulator comes to my mind. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted December 18, 2011 Share Posted December 18, 2011 regulator comes to my mind. Quote Link to comment Share on other sites More sharing options...
Leghome Posted December 18, 2011 Share Posted December 18, 2011 But if it is an internal regulator since you swapped out the ALT. it still could be but not likely. I cannot remember when Delco Remy started using the internal regulator. I remember rebuilding alternators at Delco and if memory serves me correctly the terminals looked like two I's stacked and my terminals look like two I's side by side. Quote Link to comment Share on other sites More sharing options...
UncleJ Posted December 18, 2011 Author Share Posted December 18, 2011 One more thing. The GEN light has been on since I purchased the car a few months ago. I swapped it out with a standard 55 amp alternator. I'm not sure if it is internally regulated or not. Thanks. Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted December 18, 2011 Share Posted December 18, 2011 If I remember correctly 72 is when they went fron the external regulator to the internal but it may still have external. Look on the back side of the core support behind the left headlight and see if there is a regulator there. Quote Link to comment Share on other sites More sharing options...
stangeba Posted December 18, 2011 Share Posted December 18, 2011 Pictures of the external voltage regulator, on the 70 and 71 Monte Carlos. Voltage Regulator on 71 MC Quote Link to comment Share on other sites More sharing options...
Leghome Posted December 18, 2011 Share Posted December 18, 2011 Yep that is where my 72's is mounted Quote Link to comment Share on other sites More sharing options...
UncleJ Posted December 18, 2011 Author Share Posted December 18, 2011 New twist. Last night it turned over slowly but it turned over. I drove around and came home. Tried to start about 30 minutes later and dead. This morning I went out and it turned over slowly but started. Drove around a bit and came home. Out of curiosity, I attempted to start it again and CLICK, CLICK, CLICK. DEAD. Thoughts? Quote Link to comment Share on other sites More sharing options...
Leghome Posted December 18, 2011 Share Posted December 18, 2011 My parents had a care that had a bad battery that did the same thing. After the car got warm it would not start. Sit for a couple of hours and it would. On a side note on that problem, my mother was pregnant and could not drive. Dad would have to park on a hill and mom and I would have to start pushing it down the hill to start it. Dad got called all kinds of names for his pregnant wife pushing the car. LOL LOL LOL Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted December 19, 2011 Share Posted December 19, 2011 My 72 had a external regulator I would check to see if you have one and get it checked. Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted December 19, 2011 Share Posted December 19, 2011 Check to see if it has the external regulator. Your going to want to do some testing on battery,charging system out put and starter draw. Quote Link to comment Share on other sites More sharing options...
VE3HZZ Posted December 19, 2011 Share Posted December 19, 2011 I'd say take out the battery charge it on a BENCH and then BENCH test it with a LOAD tester. I bet it fails. Now just before you do that and get the car started put a volt meter on the battery to see what the volts read. If it reads 13.8-14.5 your alternator is working fine. If not then the battery after it has time to recharge itself will turn over slowly and just enough to get it started. The voltage regulator maybe putting out (and the test will prove that) 12.5 volts which is barely enough to run the car and the battery is being depleted. Try to restart and not enough omph left. After a few hours it recharges as the chemical reaction restores the energy stored in the plates somewhat. But fully charging the battery and then doing the voltage test will determine that. If you can't do it at home, then you can take out the voltage regulator and alternator and take it to a local auto parts store that does TESTING FREE on these component (battery too) to find out the bad one. I am thinking battery as first part that's failed. Good luck Scott Quote Link to comment Share on other sites More sharing options...
cbolt Posted December 21, 2011 Share Posted December 21, 2011 I agree with Scott. The first and easiest thing to do instead of just throwing darts at what you suspect is wrong is taking the battery out and testing it. Your local auto parts place should perform this service for free. It continues to run after it is started which indicates the alternator is providing the necessary voltage. My experience has been that the external regulator is the weakest link in the chain so that would be my next test if the battery is good. Don't expect to get a good voltage regulator right out of the box. I went through about 4 of them before I gave up and changed to internally regulated, with no issues since. Good luck! Quote Link to comment Share on other sites More sharing options...
BowtieThunder Posted December 27, 2011 Share Posted December 27, 2011 The easiest way is to get a volt meter and check voltage of battery before you start car then check it after its started.Voltage should be 12-12.5v if its a good battery.After the car is started the voltage at the battery should read above 13v.If it doesnt then check the small post coming off the Alternator to see if its putting out more than 13v which it should be.That means its charging.... so the problem would be between the alternator and the battery so next check the voltage regulator Quote Link to comment Share on other sites More sharing options...
geartech Posted December 29, 2011 Share Posted December 29, 2011 Good advice here...I'd start with checking those voltages, it will give you an indication of where the problem is. One thing to note that in 72 they started using a 10SI alternator which is the internally regulated one...however it still had the external regulator on the radiator support behind the headlight, and used it. The alternator had a spacer in place of the internal regulator so it didn't have one in it even though it looks like an alternator that did. Just mentioning that, so that doesn't bite you. Quote Link to comment Share on other sites More sharing options...
MGD72Monte Posted December 29, 2011 Share Posted December 29, 2011 Yep that is where my 72's is mounted All the good advice has already been given. Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted December 29, 2011 Share Posted December 29, 2011 I think 72 is when they started making the change and started production in 73. I started gm school in late 72 and finished in 73 and we learned both. Quote Link to comment Share on other sites More sharing options...
Aaron Posted February 18, 2012 Share Posted February 18, 2012 Thanks for the pictures and information. I was wondering why my gen light was coming on after I swapped in the 454. I have a feeling it's due to the 86 alternator being used when I have what appears to be the external regulator. I hope I didn't damage anything by running it with the new one hooked up. I was carefull with the wiring and thought I was smart to remove the connector and put female spades to hook up the newer alternator. Maybe the plug being different was trying to tell me something! Quote Link to comment Share on other sites More sharing options...
Aaron Posted February 19, 2012 Share Posted February 19, 2012 I think I'll just wire it up like this for now, Quote Link to comment Share on other sites More sharing options...
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