HEI & external regulators?
 

My alternator guage tends to jump around the middle mark (at idle), particulalry with the lights or signals on. You can see a slight dimming in the lights corresponding with the guage jump. Here's what I've looked at so far:

*Checked wires & grounds for good connections- they were good.
*Checked battery. It's clean, in good condition, and reads a 12v, engine off.
*Checked battery, engine at idle, lights on and off. 15v either way.
*New belt, correct tension.

The battery stays charged. The guage only does this at idle. I have heard that externally regualted alternators, which are designed to work with a points ignition set up, may do this when the system is converted to HEI as mine is. What say you? Should I be looking at an internally regulated alternator?

Thank you.

Your dimming /brightening lights is a fairly common problem with external regulators. It can be cured with a good regulator. Internal regulators can do the same thing, although it is not as common.

Replacing your external regulator will probably cure the problem. Replacing the alternator with an internal regulator will work, also.

Jim

I will apologize upfront for the hijacked post. but it does relate to this subject. I am now currently on my second HEI since May for my Suburban. It is almost completely original. It even has the old Delco 62 amp externally reg. alternator. It has given me starting problems that are intermitent and I had changed the module out several times on the old HEI. It would work for awhile then go back to intermitant non-starts. So i picked up a rather new used HEI and it solved the problem for about a month and now it's back.

My lights don't dim that I can tell. but when my stereo is running and the bass notes hit it dims the lights on the face. I am in the process of installing two 10" subs and a set of Amps 560 watts and 900 watts. So I planned to update that old external 62 amp alt. for a more modern 3 wire 100 amp or so.

1st - Could any of the starting problems be caused by the old alternator set up with the modern HEI?

2nd - Should I move a little quicker to switching out to a more modern Alternator?

3rd - Could a simple regulator solve most of my problems with starting? I know I still need a better alt. before I get the amps installed (next month).

HEI will work fine with the old charging system, and the old charging system is fine with the HEI.
Old externally regulated set ups do this becouse the alt has problems at low RPMs.
An internally regulated alt will probably cure this.
IMO, getting a high quality external regulator is a waste of good money. Consider converting...again...IMO.

I agree with Longhorn Man 100% on this one. Your dim lights and oscillating ammeter are not a result of the HEI drawing more current from your 62a alt., but the RPM at which your alternator is turning. I believe a higher amp alt. will cure the problem (90-140amp) given the higher current demand of your stereo system etc. The stock alt. on my '72 GMC was 42a leaving much to be desired with all the lights on and signals/brake lights on. Internally regulated alternators are just faster to catch up with the demand being solid state as opposed to the old electro-mechanical ext. regulated set-ups.

I have the same setup a Zonaman. The last time I had this problem it was the
ground to the regulator itself. I took the regulator off; cleaned everything and
it went away. This is after I had cleaned and added grounds all over the
truck.

EdB