Need help with flickering lights

[Miller Mike]

I have a problem with my 77 scout that I can't seem to get anyone to fix. I am looking for ideas or suggestions. My Scout has a 345 motor. The problem is this: at 55-60 MPH the lights flicker and the alternator gauge jumps to "charging". If the speed is reduced, the problem stops (yeah, I know, don't go that fast, but I CAN'T drive 55). The alternator was tested and diagnosed as "overcharging". The battery tested "good". Since then I have put in 2 new alternators (with internal voltage regulators like the original one) and..no help..same problem. I installed new negative and positive cables and clamps, I even ran another negative cable to the frame..still no help. Has anyone else had this problem, (or am I just cursed?) Or, better yet does anyone have any ideas or suggestions of what I should try next. My wife says its haunted and the message is that I should just slow down...Help.

Does this only happen when the lights are on? If so it sounds like a short.

Also, try pulling the bulkhead connector apart then clean it with electrical parts cleaner, re-coat the contacts with a little dielectric grease and reinstall it. It could be a certain vibration starts at 55 mph and causes the bulkhead connector or headlight wiring to cause problems.

Everytime I have had electrical problems I start with the bulkhead connectors and most time the problems go away. I always recommend starting there.

It may be time to re-wire the charging circuit. I have done this and replaced the headlight wiring too.

The ammeter going to charging means there is a draw on the battery. The alternator replenishes current drawn from the battery.

BTW, did you know we have a "club" here in VA? It's called the Old Dominion Binder Association or ODBA. It's totally informal and we get together for gatherings a couple three times a year. Actually we just started it last September. No dues, no officers, just folks enjoying their binders. There is a gathering this coming weekend in the Blacksburg area.

There is a friend of ours in the Hamption area. His name is Duly and he is a "Coastie". He has a 77 Traveller. He hasn't been to a gathering yet because of his schedule but he comes up here to Apppomattox area to pull wrenchs from time to time. I'll mention to him there is another Scout owner in his "neighborhood". He shows up here in the ODBA section on this BB from time to time.

[Buddha's Ghost]

Couple of questions assuming you've ruled out the Bulkhead connector as was advised in your other post:
1. Does the ammeter swing left or right and how far?
2. Does it only do this when the headlights are being used?
3. Is it the original pulley on your alternator and if not how large is it?
4. Who are you purchasing your alternators from?

[drobson]

Check the wires coming out of the 2-wire block on the alternator. I had one crack loose and cause similar problems. Good luck.

[Jay Tabor]

dont forget the wires at the solenoid need to be clean and tight also.could be a loose connection at the fusible link to the tengauge charging wire at the starter solenoid.
but like was said check the BHC and also the wires attached to the ammeter might be loose.
how tight are the fan belt[s]?

[Miller Mike]

Thanks guys for replying. I am NOT a mechanic, but I have a good guy and he is trying all the suggestions. I will get on and let you know. I am new at this and did not realize I could reply. Sorry I took so long to say thanks

[Ben Segrest]

Originally posted by Miller Mike
I have a problem with my 77 scout that I can't seem to get anyone to fix. I am looking for ideas or suggestions. My Scout has a 345 motor. The problem is this: at 55-60 MPH the lights flicker and the alternator gauge jumps to "charging". If the speed is reduced, the problem stops (yeah, I know, don't go that fast, but I CAN'T drive 55). The alternator was tested and diagnosed as "overcharging". The battery tested "good". Since then I have put in 2 new alternators (with internal voltage regulators like the original one) and..no help..same problem. I installed new negative and positive cables and clamps, I even ran another negative cable to the frame..still no help. Has anyone else had this problem, (or am I just cursed?) Or, better yet does anyone have any ideas or suggestions of what I should try next. My wife says its haunted and the message is that I should just slow down...Help.

I had this same thing (more or less) happen to me. When my alternator went out, I replaced it with a 95 amp Burbun alt. It acted pretty much the way you describe until I rewired it following instructions I got from Doug Shailor (who got them from someone else, but I can't remember the original source). Anyway, if you did install a higher output alternator post back and I'll try to dig up the info. on the rewire. Good luck.

[Ken Edgington]

Mike, also check the ground to the cab. Engine to cab should have a ground strap just like you did to the frame.

HTH
Ken

[Duly]

Hey Miller MIke,
Nice to know there is somebody in Hampton with the same great taste in vehicles as myself!!! If you wanna work on them sometime or just show em off to each other let me know. You cant miss mine being camo!!!(or maybe you can ) Let me know if you need some help. May not be much help cause I am still learning just ask my Professor Shailor!!!! HAHAHAHA!!!!

later yall,
Duly