66 Cruiser

Sounds as if the alternator may still defective in spite of the rebuild or perhaps the regulator is no good (or wrong). Can you take it to a battery warehouse/AutoZone/etc where they will check the alternator? Paul Johnson

How far into discharge? Does it go back into charge when you raise the RPMs? Everything 60's I've ever owned with an AMP meter would show a discharge with all the accessories on and the lights when I stopped for a light. The lights would dim and the wipers would slow down. It's not unusual. After replacing a mechanical rregulator with an electronic from Dave Thiebault the swings are less severe on my Avanti, but it will still drop with the additioanal drain of lights and heater.

If the regulator was mechanical it may be necessary to "polarize" it before running the car. It's been so long since I had to do that I can't remember how.

Get a voltmeter and check the battery with the car off. Should be

12.5+ volts. With the car running, accessories off and idled up a little it should be very high 13's or low 14's.

I had a problem with the plug going into my alternator. The spade terminal just didn't fit tight enough, Make sure the regulator is grounding tightly to the body. Don't rule out the battery terminals and any accessory wires attached to them. Uf you can get behind the dash check the connections on the amp gage itself.

ErnieR

GM alternator?

got a volt meter?

take ALL the wires off the alternator.. set volt meter to ohms... connect one lead to the battery post on the alternator, and the other to alternator case.. get a reading.. x number resistance.. reverse the leads and measure again.. should be a big difference.. IF its REAL close to same, got a bad diode in alternator.take it back..

while the alternator is unhooked, measure the battery voltage-

12.6/8 volts or so, assuming battery charged..

hook alternator back up, and measure again..should be same start vehicle and see what its at now...13+ or so... do NOT turn the lights etc on..

set the volt meter to AC and go across the battery again while running.. should be IIRR LITTLE AC voltage present..

car off, set for OHMS.. check between the alternator CASE and the battery negative.. SHOULD BE real close to 0 ..

if NOT.. start car, and take battery jumper cable, or a bigger piece of wire-10 gauge, and jump between the alternator CASE and battery negative.. IF the thing sparks, then you might be missing the ground wire on the engine to battery-dirty connection or the like..or a bad end on the battery cables..

and you MIGHT have loose/dirty connections on the amp gauge as well.

--Shiva--

Thanks, I will start checking it out beginning tonight!

paul

Intersting problem here. My '65 V-8 Cruiser has the opposite problem. The Amp gauge point way over to the charge side under normal conditions. When I put the lights, etc. on the needle heads toward the discharge side, but never gets even to the middle. Ideas?

Joe Roberts

I had the same experience on my 65 Cruiser with the six. The alternator was bad (it was only 6 months old). When running, it would be slightly to the right of center on the ammeter, but when the headlights were on, it would go to discharge--eventually to the point it wouldn't start unless I ran it without the headlights on. Replaced the alternator and was good to go.

FYI, mine always shows a charge when running with no lights, etc. At night, it goes to about center to just slighly to the left of discharge, but not much.

It sounds like your alternator is working (like mine was), but just not putting out like it should.

Mark

65 Cruiser of the Cruiser Registry > Intersting problem here. My '65 V-8 Cruiser has the opposite problem.

A bad regulator will cause an overcharge, start by checking the voltage at the battery with the car running, with and without all the lights etc on.

Joe