71 Duster

So I'm driving to work this morning and everything is fine. All normal, same as every other day. Start off cruising on the highway at about 2500 rpm and all of a sudden everything dims down. Heater blower slows down, dash and headlights dim, and the turn signals stop working. Once I get off the freeway and sit at a stoplight for a bit... EVERYTHING startsworking fine again.

About 3 months ago I installed a new voltage regulator to try and cure the same problem. Alternator is good and the battery is 5-6 months old. Checked the alternator belt when I got to work and its tight. This one has me a bit baffled.

That is odd. New regulator does not equate to good working regulator. Is it electronic or mechanical type of regulator? That thought aside, I think you have a bad connection somewhere in the charging circuit and power delivery to amp gage, and or bad ground connection.

Check the condition of the ground strap connections, and the look for any voltage difference between negative battery terminal, and all grounded outer cases of alternator, electronic spark controller if equipped, and voltage regulator. Intermittent, that is, loose, or badly corroded ground connection could cause voltage drop-off (lights dimming etc.), also can cause a great deal of heat (melt-down) at that location.

Also check connections at starter solenoid and plus battery terminal, as well as alternator’s ¼â€￾ bolt power lug. Check the alternator power feed (#12 black), the #10red, and # 10 brown conductors at bulkhead connector for heat damage, tightness, and corrosion.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Thanks for the reply!

The regulator is a Wells electronic unit. All ground straps are good. I replaced them a few months ago with new ones I made in the shop. And the amp meter was bypassed. The wires were cut, stripped back, soldered and shrink tubed. I'm also running a Summit racing
Electronic ignition box off of a relay set taken straight from the battery.

Could is possibly be a fusible link that's half gone or somehow broken inside the insulation?

Ill check the bulkhead connections & all lugs for power and continuity when I get home.

Thanks again for the help!

I've seen the same symptoms in my '71 come from bad alt. brushes and a flaky regulator; both were cheap and easy to replace.

Found it! Just before the distributor went south unfortunately.

One of the bulkhead connectors was not quite seated. I also had a fuse that was blown, but not totally. I've never seen it before, but it was blown at one end of the element and barely making contact internally. it would slowly break the circuit as it heated up.

Thanks for letting us know. Beware corrosion at the bulkhead pins - it's a common problem. I've also seen fuses get flaky, but not quite like yours.