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Charging/starting issue?

477 Views 5 Replies 3 Participants Last post by  68gt390bench
Hi all,
My buddy is having a starting problemn with is new '69 Mach 1.
Yesterday we replaced the alternator since old one was shot and we found out under a load there was 16.5V running thru the system. So we replaced the voltage regulator and then things seemed fine, about 14.5V under a load. This all started a few days ago b/c he friend the alt. harness when he swapped the battery cables!
We thought we had everything fixed and he just called me to tell me he drove over to the gym and when he came out 45 mins late the car cranked but got slower and did not start. He needed to get a jump and the car started a he drove home fine.
I am thinking he needs a new battery. What does everyone think?
The only thing that has me wondering is why did the casr start w/o a problem tonight when he went out. Did driving the car over to the gym slowly train the battery and when he went to leave it didn't have enuf cranking power?
Unless something is slowly draining the battery that I don't know about....but if that were the case you would think it would have drained over night and would not have started tonight.
From what I know there are only 3 major parts to the charging system, alt., voltage regulator and battery, only think not replaced so far is the battery.

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the battery may not be charging with correct voltage at terminals. go to AutoZone and have them test it because if you see +14.5 V at term the reg/alt are working . you may have done some internal welding inside battery with the reversed terminal opoeratiion.
Take the car tp someplace like Sears Auto and have them do a load test on the battery. Make sure its charged up first. You'll have your answer for free.
We did have Sears do a test yesterday and that is how we found out the volt. regulator was not working right (we were seeing 16+ V under a load...) so we replaced the reg. and then we were seeing 14.5V at the terminals.
I'm thinking it is the battery but it was odd how it did not start today after being driven and this issue didn't happen at all yesterday.

Has the timing been played with prior to this? I used to run the timing so far advanced that when the motor was warm it would hardly turn over at all and I would have retard the timing just to start it.? Just a thought
I am not too sure, my budy just got the car. However, I do know yesterday when we were driving it around and hot starting it, it was firing right over.

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