86 Interior & Dash lites FLICKERING

[C4TOMCAT]

Hope you can help me with this problem. My cousin has an 86 corvette automatic and recently he has been experiencing his interior light flickering. They do not flicker until the car is started, then the instrument panel lights flicker about 5 seconds after the car starts. Also the interior dome lights flicker at the same rate as the dash. Is there a common source that feeds these circuits. He has disconnected the alternator connections, cleaned all the grounds, except the one he has been told is behind the IP but he has not found it. The 87 manual he looked in shows it but he is unable to find it on the 86. There is also one that is supposed to be to the left of the steering column but can not find that either. Is it under the insulation? He has put new distributor cap, plugs, wires and still it flickers. He has cleaned the back terminals of the instrument cluster thinking it was the dash contacts. He is also picking up a popping noise in the Bose system.....are these interrelated or just co incident. Any help will be greatly appreciated

 

[c4c5specialist]

questions, please

Hi there,
I would look to see what is flashing other than the dash lights, and the interior lights.
Possibly a warning light on the dash, maybe??
Does the lights glow dim, or very bright, in comparison to what they were before they started doing this weird stuff??
Please let us know, c4c5

 

[C4TOMCAT]

c4c5specialist

Thanks for the reply. There are no other lites flickering except the interior and dash lighting. headlights, brakes, turn signal etc are all off. I can of course dim the dash with the dimmer switch but it does not change the flickering...only the light level. would the alternator, if not connected but still turning with the belt on cause the flickering if the diodes/regulator is going bad. only thing left for me to try at this poing and see if it flickers with no alternator on the car. thanks for alls comments and assistance.

 

[69MyWay]

It is not a good idea to run the car with the alt disconnected. Although, it may be the only way to test your theory.


My 85 and 86 flickered quite a bit. However, I could usually watch the pulse in the flicker with the headlights so I knew it was the entire charging system. On both cars, the alt when out very soon after. When the digital dash went out, it suddenly was too dark to read very well. I sent it out for the standard repair and everything was fine after that.

Keep trying different things until you isolate the problem area. Maybe you can put a piece of tape on the light sensor and see if they still try to flicker.

 

[c4c5specialist]

It would make sense

Hi there,
Your alternator theory makes sense, especially given the fact that all your lights are winking.
I would say that you probably have a defective diode bridge.
Just make sure that you check all your terminals at the battery, make sure they are clean, and your grounds are tight.
Best to you, c4c5

 

[C4TOMCAT]

86 flickering FIXED

86 flickering lights FIXED

Well, the problem was the alternator as some of you responded. Even though I disconnected the terminals for the first check I assume the fact it was still turning with the engine that whatever failed internally caused enough of an induced field that the wires in the engine area picked it up and magnified it..or the computer was affected by it and caused the lights to flicker. Once we took the belt off and ran without the alternator, it supported the conclusion the alternator was the problem..new one is on, and all is normal....thanks for all the responses.