News:

Due to a technical issue, some recently uploaded pictures have been lost. We are investigating why this happened but the issue has been resolved so that future uploads should be safe.  You can also Modify your post (MORE...) and re-upload the pictures in your post.

Main Menu

Pulsing Lights on my '72 CDV

Started by Gary Christensen CLC # 21112, November 27, 2018, 03:57:36 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Gary Christensen CLC # 21112

The lights on my '72 "pulse".  I also notice that my turnsignal speeds up and slows down.  What would cause the electrical accessories etc. to do this?  Any ideas?

fishnjim

I can't recall exactly, but my memory is the feedback of the charging system and turn signal flasher that causes this.   It's either an alternator, flasher, or both swop for starters.
You can monitor voltage with a DVM and see what's going on.  Drop out each component and see if goes away.   I don't think they used circuit breakers and relays yet.  Relays can set up a feedback.   But the flashers changed away from thermal.   Some of the older thermal cars had similar issues.   No longer a problem these days.  But if you use the wrong type in the wrong car, problems ensue.   Then they added 4way emergency flashers and they caused some initially.
They changed alternators to internal control during that time and there was a few hickups.   So adapting a newer alternator may cause issues in older.
Perhaps a ground or wire issue involved.  They changed to single wire alts later I think.   Any older auto electric shop can diagnose.

dplotkin

I suspect a bad diode in the alternator. Put a DVM across the battery, engine running, set it to AC volts and report reading.

Dan
56 Fleetwood Sixty Special (Starlight silver over Dawn Grey)
60 Buick Electra six window
60 Chrysler 300 F Coupe
61 Plymouth Savoy Ram Inducted 413 Superstock
62 Pontiac Bonneville Vista
63 Chevy Impala convertable
63 Ford Galaxie XL fastback
65 Corvette convertable 396
68 Chrysler New Yorker