Charging Issue?

[Fastair6]

I'm having a charging problem. When the motor is cold i get 13.4 to 13.6 volts on the scan master. After about 10 minutes of driving the voltage drops to 11.8 to 12.0. Shut the car off for a few minutes and start it again the charging voltage will be 13.4 to 13.6. I've changed to another alternator which is also used, but the same simptoms return.

Does anyone know if the light in the dash has any affect on the charging system? Specifically, if the bulb is burnt could this cause a problem. Is there a timed delay relay or electrical device in the system?

Any help with this would be greatly appreciated.

Thanks.

 

[TurboBuRick]

If the dash bulb is blown the system will not charge at all. No time delay.

Check the connection/wire on the alternator plug. Recently had a friends car that would stop charging. We traced it to there.

GL

 

[Fastair6]

Thanks for the help. Seemed ok, but i didn't take a close look at it.

Thanks again.

 

["Turbo-T"]

Or just do what I did and get you a Caspers field fix harness and say goodbye to the "quit charging because of a blown bulb/bad connection at the socket" blues.

 

[davelostmissing]

Voltage drops when the fan kicks in?

 

[Hacksaw]

Voltage regulator getting weak as it warms up?

http://www.vortexbuicks-etc.com/alternatorselection.htm

The lower the temperature the higher the charging voltage, and the higher the temperature the lower the charging voltage. The "normal" charging voltage on a typical application might be 13.9 to 14.5 volts at 77 degrees F. But at 20 degrees F. below zero, the charging voltage might be 14.5 to 14.7 volts. On a hot engine on a hot day, the normal charging voltage might drop to 13.5 to 14.2 volts. This happens because the voltage regulator is tied to temperature. On a cold day, the internal resistance of the battery increases, and, it takes more voltage to charge the battery than it does on a warm day. You can observe this voltage drop by measuring the voltage at the back of the alternator when you first start the engine and then watch it drop as the alternator begins to warm up and the battery is charged.

 

[chopped39]

Voltage regulator getting weak as it warms up?

Alternator Selection

X2 Get the Casper kit for the dash also. My bulb was loose in the socket after the dealer had dash apart but my car died on the road