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Need help finding short circuit

Got in my Beetle last night, turned on the ignition, hit the start button, and nothing. I noticed the ALT & oil pressure lights were not as bright as normal so I turned the Head lights on. Nothing. Checked the Battery with my meter and it has 11.2 VDC (the norm is 12.4). All fuses are good so I hit the Head lights again and they come on. I jump in, turn the key and hit the start button, Vrroooom it starts. Checked the battery again, 12.4 VDC. Could the Light switch cause this (?) Where should I start looking. This is a BAJA and the wiring is not factory. TIA

Reply to
teknoclash
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Reply to
teknoclash

If you had *both* the meter probes on the battery posts themselves, then I'm going to say "bad battery". Sometimes the posts develop an intermittent high resistance connection *inside* the battery.

Keep the meter with you so you can double check the measurements next time it happens.

Jim

teknoclash wrote:

Reply to
Speedy Jim

After you get the new battery in, measure the charging voltage while running. Should read between 13.5 to 14.5V. If less than

13.5V, the battery is not gett>
Reply to
Speedy Jim

Update. Today I checked the battery (car at rest) and had 11.4V. I started the car and the Voltage fell to 9.5 or so and went back to

11.4. Let the car run and watched the voltage and it did make it to 13.4. Turned the lights > After you get the new battery in, measure the charging voltage
Reply to
teknoclash

Reply to
teknoclash

I've lost track of what year this car is. If it's late '71 or newer, there is a contact in the Ignition switch for the headlights which may fail. The Headlight switch might be the cause, but rarer, I think. The dimmer relay is a more frequent problem.

If the problem is so intermittent, you will have great difficulty tracking it down because you can't even get a meter on it in time.

I would try wiggling connections on the items I mentioned while the lights are on and see if you can replicate it.

Jim

teknoclash wrote:

Reply to
Speedy Jim

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