kamaro68

When I drive my car it occasionally starts flippin' out.

My volt meter jumps all over the place. My tach starts jumping also. All the lights (interior and exterior) start flickering. Sometimes it will go away and sometimes it will stay that way?

I had Kragen run all tests on the battery (battery is good). I checked all the wires and grounds. Everything checks out okay.

This happened on my old motor. I rebuilt the motor and installed a new one-wire alternator and I also replaced the Summit HEI distributor with an Accel HEI distributor. Still having the same problem.

While this flickering occurs it seems like it doesn't charge the battery either. My battery will run down (only when the flickering is occuring).

Help!

Car Specs:

1968 Camaro Coupe
383 Stroker
670 CFM Holley Carb (4 barrel)
Performer RPM Air Gap Intake
Accel HEI Distributor
Be Cool Radiator with dual electric fans
March Front runner kit with Sanden AC Compressor
TH-350 with 3200 Stall

byrons1502

check the alternator. sounds like you may be having one starting to short out.

kamaro68

That's what I originally thought. I have two different brand new alternators that I have used. Both do the same thing

angel71rs

Is it still original external regulator type or have you converted to internal?

kamaro68

Good question. I am assuming they are internally regulated. Both alternators I had are one wire alternators.

Sounds like this may be leading to a grounding issue or loose wire somewhere???

angel71rs

One wire alternators (all are aftermarket) are internally regulated. If you eliminate any wiring issues, I'd have only one guess as to what it may be. Regular alternators (internal reg or external reg) have excitor voltage fed to them on one of the 2 small terminals. Excitor voltage comes from key switch, thru "alternator" bulb in dash, then to excitor input of alternator. No excitor voltage, no output from alternator.

When alternator starts outputting voltage, it also puts 12v on excitor terminal, bulb has 12v on both sides of it, no difference in voltage across bulb = no current flow, bulb goes out to let you know alternator is outputting.

One wire alternators are self exciting. When you crank up the engine, you're supposed to give the throttle a blip to self excite it. If you don't, no output. Read more here:

http://www.alternatorparts.com/what_...alternator.htm

kamaro68

great info angel.

I do have a 1-wire alternator.

I always have to "blip" the throttle as I removed the choke on my carb.

I noticed it happens more often when my fans come on? I also had this problem prior to running electric fans however?

I hate electrical issues...

Sack

I would look for a bad ground. You can never have to many grounds

angel71rs

Probably just a symptom of a weak charging system.

Try this. while the engine is running, put the negative lead of a multimeter on the battery -. Then measure the voltage at the output stud of the alternator, then measure at the battery +. The readings should be close. e.g. if it reads 13.8 at the output stud, a reading of 13.6 at the battery + would be good. If it drops more than say .3-.4 volts, there is excess resistance from the alternator to the battery.

If that checks good, shut it off, disconnect battery, and take a resistance reading from the case of the alternator to the - battery cable terminal. It should be a very low reading. if it's more than a few ohms, there is resistance in the ground path.

typical problem areas where you can find resistance: where the negative cable connects to the block (rust, paint, etc), the crimps on either of the cables. If it's the bolt type battery terminals, there is a spacer hidden under the plastic sheath where the bolt goes. Use a small screw driver to dig it out and clean it on a wire wheel or even sand it on a cement surface. Use a brush type battery terminal cleaner to clean the recess where the spacer sits. The terminal itself is made of stamped brass and is very thin. The spacer gives something for the bolt to securely clamp to the battery.

If it's clamp type terminals, take them apart completely for cleaning. Sometimes the strap that clamps the cable to the terminal does not squeeze it with enough force if the cables are light gage. Flip the straps over and it will grip tighter. Also make sure that the alternator mounts are clean where they bolt to the head so alternator gets good ground. You just have to locate/fix any possible spots where resistance can lurk.