engine and drivetrain Electrical Issue

[JOHNAHOF]

The white 76 02 has a new battery and what looks like a new alternator. Both test out in good working order. I can charge the battery and the car runs good for a few days. Eventually it starts getting low voltage to the spark and over time the car will not run.

Other information that may or may not pertain to this issue.

1) The horn works intermittent.

2) When the turn signal is on the temperature gauge bounces with the signal.

I plan to replace the positive and negative cables from the battery. Check and clean the connections at the alternator and relays. There is a small wiring loom that runs from the relays on the driver side fender well, along the side of the engine block... I plan to inspect each of these wires and follow them to end and inspect each item.

Electrical issues are my weakest point. Does anyone with knowledge in this area have any advice before I start?

Thanks,

John Hoffner

[Mike Self]

First--intermittent horn and flickering gauges aren't really related to your battery problem--but are most likely an easy fix--for another post!

To run down your current problem...you either have (1) a bad battery (and new ones can be defective) or (2) something wrong in the charging system.

A bad battery is easy to check--have a shop do a load test on it.

Charging system tests are performed free by most auto parts places. Likely problems are (1) a weak or dying alternator (2) bad voltage regulator (3) the wiring between 'em.

Before buying expensive new parts, check the easy stuff first:

--the three prong plug at the back of the alternator (and also on the underside of the regulator)--are they both tight and clean?

--Is the brown ground wire that runs from the alternator to the engine in place and not internally fractured? (do a continuity test on the wire)

--Are all three battery cables clean and tight at both ends?

--Is the alternator warning light on the dash functioning? If that bulb is burned out, the alternator won't charge!

That should get you started...post what you find or more questions...

cheers

mike

[ponyboy]

that sux that the bulb in the dash stops the alt from working, wow...

Thats not on pre 73 is it?

[Guest Anonymous]

Sounds to me like you have a bad ground wire. Check your ground to the body and to the motor....steve

[hpsenicka]

I strongly sugggest you clean and tighten your battery ground cable connections before you invest any additional time troubleshooting electrical bugs.

It is very important that you have a ground (negative) cable running from the battery to the chassis, as well as to the engine. In many cases the chassis ground has been compromised or removed and this can cause some of the symptoms you described. I can almost guarantee that your flickering temp guage will be fixed once you fix your grounding problem.

The original chassis ground was accomplished by connecting a ground strap directly from the battery terminal to the chassis, but the same effect can be achieved by running a ground cable from the engine ground connection point to the chassis.

In addition, there are a number of points on the vehicle where the wiring harness is grounded to the chassis... these should be cleaned and tightened as well.