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I will take a stab at this. Just replaced my alternator and decided to replace my voltage regulator and connector at the same time. I can't get a reading over 12.4 volts anywhere in the system (battery at 12.4). Checked all the wires for continuity and resistance, all good with only a bit of resistance on the brown wire going from the connector back to the firewall. Driving me nuts so I took the new alternator to the local O'Reilly's and had it bench tested, tested ok 13.4 to 15.8 volts ( even said the voltage regulator was fine! Regulator is external! hmmm.) After a few more You tube videos later I did a diode test on it. It failed. Would a failed diode cause the alternator not to put out voltage from the BAT term on the alternator?  No buzzing from the voltage regulator, adjusted tension spring, nothing. Maybe I got a bad alternator from Summit Racing to begin with. My "ground" is good and both of my multimeters are working fine. Anything else I should check before I send the alternator back? Bench test vs. what is happening in the car makes me scratch my head...  In addition I have gone through previous articles in the Riview and nothing quite hits home. I tried the  suggestions.  You Tube videos helped some, but problem not solved. Thanks for any suggestions you might come up with ....

Edited by TallJohn
left out info (see edit history)

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Benefits of AACA Membership.

More China crap. Send it back.

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Suggest putting in a Powermaster, that's what I did. It came with test data!

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I agree, easiest is to change the alternator and regulator with quality parts. If all of the wiring looks good cheap parts are  problem.  I assume that the alternator light comes on when you turn the key on and then stays on when the car is running?

 

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May or may not be your issue. I had a similar problem going to the BCA National Convention in 2018. Battery died for no apparent reason. Replaced battery, still not charging from the alternator. Coincidentally, pulled into an O'Reilly's and got a voltage regulator as a test at a Tires Plus said it was bad. Still not charging. Replaced that voltage regulator with another one. Still not charging. Got a new alternator. Still not charging. In the end all components were good, new and old. The culprit was a bad connection/connectors at the alternator. They looked good with a visual inspection. Old connectors snipped off, new connectors put on and the problem was solved. Of course, it was in the high 80's and humid while we were changing all of this stuff in the O'Reilly's parking lot and my brother-in-laws driveway.

 

Bill

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Problem partly solved. I had bought a new connector and wired in the blue and white wires accordingly. all continuity good as stated before . Although my splice was good, the leads in the head of the plug were reversed  from the parts store. I switched them and car was charging immediately. Lesson learned on the blu and white wire to the back of the alternator. Diode test was good too!

 

Now the new issue. Amp light stays on and the voltage regulator is buzzing loudly at idle. Very annoying. System is at 13.3 at idle and 15.2 at higher rpm. Buzzing stops with acceleration , louder as I come to a stop. Amp light is continuous while the car is on.  Any thoughts? Thanks. Ad thanks Riviera 63 for leading me to take a second look at the connector.

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How old are your battery cables?  Are they at least a 0 (zero) gauge or thicker.  The cheap stuff hanging on the racks at your local jobbers just can't handle the load.

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Positive cable is brand new. Ground cable three or four years old. 

Are you thinking that would be the cause of the voltage regulator buzzing so much as well as the amp light staying on even though the system is charging?

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Doubtful that battery cables are at fault since they are fairly new.  What gauge are they???  Do you know or how to tell???  Probably still a bad V/R

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sounds like now that the regulator is not operating correctly. It is causing the alternator to charge too much. Will fry the battery and could boil it over

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I think there may be a reverse polarity issue going on some where  that’s causing the regulator chattering and light to stay on.i know its too late now but i always try to have original to the car components rebuilt i.e. starters, generators ,etc. whenever possible

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Do a continuity test and verify that the wire coming from the F terminal on the back of the generator is the one that actually lands on the F terminal of the regulater. Do the same with the R terminal. Make sure you disconnect your battery before doing this. Then check each wire for continuity to ground , then check for continuity between the two wires. Al this must be done with both wires disconnected on both ends. Good luck

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I had done a continuity test to begin with, but I will do it again to double check. When I started it this morning I increased VR to 14.2 at idle, no buzzing, but Amp light remains on solid and the VR was clicking at the speed of a turn signal and amp light was flickering at the same rhythm of the points tapping each other. Car is charging fine. Took in for a spin, now no  clicking at all ( Hmmmm). Charging fine but amp light still on...ugh

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Thanks for the replies. Did some more tinkering with the VR this morning. Amp light barely on at idle , goes away at higher rpm. VR Quiet, charging. I will keep tinkering....Continuity is good, double checked...Thanks all...

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