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Just picked up this 1971 Cutlass Convertible last Tuesday. Florida car last 3 years. Spent it's life in Texas. Good condition runs great. However did find one issue. When the engine is running all the lights flicker. There is also a clicking from behind the dash traced to the voltage regulator you can hear. Clicking is the same rate as flickering. Everything works. Car is charging, holding voltage overnight etc. I tried another alternator, w/ same result. I installed a new Delco regulator, & that one caused the ENG light to come on w/ key OFF. It also got warm smelling. Any ideas?
I suspect the regulator and it sounds as if the replacement regulator was worse off than the one it replaced. Dod you ensure the body of the regulator is well grounded to the firewall? There should be a star washer between the regulator and the firewall.
Last edited by Fun71; July 30th, 2022 at 10:32 PM.
The lights on my 71 Cutlass also flicker especially when there is little load(interior lights is all) and engine is just started on high idle. But no clicking. Seems like you were on the right track with replacing regulator, but maybe replacement is bad?
Suspect you have a short between #3 & #4 or between #1 & #2 wires (especially if you smell something). I suggest you follow the diagnostics pathway in the electrical diagnostics section of the Oldsmobile 1971 CSM. If you don't own the 1971 CSM, suggest you purchase an original used paperback edition. Pretty simple to follow the diagnostics pathway(s).
I had this exact problem on one of my cars. Check and clean all the wires that are connected at the battery stud on the horn relay. Corrosion here can cause voltage level problems.
Would I have ruined a new voltage regulator if I took a shortcut to replace it? For example, not disconnecting the battery, then plugging the connector onto the regulator BEFORE grounding/mounting it? This might explain my issue w/ a new regulator not working correctly.
Would I have ruined a new voltage regulator if I took a shortcut to replace it? For example, not disconnecting the battery, then plugging the connector onto the regulator BEFORE grounding/mounting it? This might explain my issue w/ a new regulator not working correctly.
Chances are that did not cause the problem. Is this an OEM style mechanical regulator or a newer electronic one? The latter are obviously susceptible to damage from voltage spikes, but frankly without the alternator turning the chance of that happening is extremely low.
I merged your 2 threads because the first thread had all the background info.
No, it did not cause your issue. There will be a burning smell sometimes with the new VR as there is a big resistor mounted on the back that heats up. The voltage reg that lights your gen light is bad. New does not necessarily mean good when it comes to voltage regs, there is a large failure rate among them especially the electronic ones. The part number for the electronic ones that most use on these cars is VR715.
Thank you. I reread the instruction sheet again & it also mentioned that new regulators will sometimes smoke off varnish from the resisters on the back of the unit. I appreciate the advice. I'll try installing the regulator again, the correct way & see if it works. Today, I had my "new" car at the transmission shop & it check out w/ no troubles. I replaced the windshield washer pump & now the car is all sorted out for a while.
Update on the "flickering" lights. I tried several regulators with poor results. Finally looked under the dash to check for a blown wiper fuse. I found an aftermarket alarm system wired into almost EVERYTHING. After disconnecting 2 power feeds, I cut & sealed off the other wires, removing as much as I could. Flickering solved. Another surprise w/ a used car. Not too bad for 51 years old though.
July 30th, 2022, 09:24 PM
