Something bizarre happening...

[rumrumm]

I have an electrical issue. I'm driving my coupe and everything is normal. The voltmeter reads around 14. Then, all of a sudden, I hear a click, and my voltmeter starts jumping from 11.5 to 17 to 13.5 to 14.8. All over the place. Nothing like the fuel injection, the distributor, the A/C or the other electronic components appear to be affected by this. I have Dakota Digital gauges, and I called them and they said nothing in their system would cause a click and cause the voltmeter to go crazy. I replaced the old battery with a new Optima red top unit and I changed out the alternator with another that I had. The problem is still there. Any ideas?

[34ford]

A clicking sound like a relay. Just a thought.

[kb426]

My guess is that there is a strong load that is brief that is causing the charging system to start filling the load and then overcharging as the load disappears. The only other click besides a relay that comes to mind is a circuit breaker. Last on the list is a broken or bare wire that makes contact  briefly or a ground that is doing something similar. You might try removing fuses as a method to isolate  which circuit is at fault. Is it possible to disconnect the alternator and drive the car some and see if the issue continues? 

[jaybee]

I think start by getting the battery and alternator load tested. Maybe your battery is starting to short out internally or your voltage regulator is going bad.