Volt meter moves when blinker is on

[MaxmillianS]

Like the title says when I have my blinkers on the volt meter moves about a cm every time they blink, think its just a bad ground?

[Irish_Alley]

its normal as far as i know. think of it like this you alt doesnt just produce 14 volts all the time, it produces whats needed i.e. 14.1 volts just running vs 14.1 volts with the headlights on. it puts out 14.1 volts depending on the draw and it takes a split second for the alternator to sense how much draw your putting on it. so when the volt needle moves its because of that slight delay

[enaberif]

Blinkers shouldn't make a volt meter move at all. Technically the only time you should see a volt meter change is under extreme heavy draw like power windows.

[blazer74]

Possible diode in the alternator


Sent from my iPhone using Tapatalk

[MaxmillianS]

Alternator is brand new as of a month ago

[blazer74]

Was it doing this prior to the alt change?


Sent from my iPhone using Tapatalk

[Irish_Alley]

put a volt meter on the battery and see if it really does drop. could be a bad ground, but i know most if not all of my trucks do this

[enaberif]

put a volt meter on the battery and see if it really does drop. could be a bad ground, but i know most if not all of my trucks do this

LOL then you got a problem somewhere. This is not normal behavior.

[Irish_Alley]

oh i have a lot of problems lol

[Shifty]

My 87 V30 and 87 Z/28 both do this....it may not be normal, but the Z/28 has had the same alternator for about 50k, battery 4+ years.

[frotosride]

Because of the wiring design there are often voltage drops in the cab. Like Irish-Alley said the alternator puts out varying voltage. If you have a three wire alternator then the small red wire that goes directly to the positive output lug is the voltage sensing wire. If you relocate this wire to the cab end of the wiring harness you will notice a drastic increase in electrical performance. The sensing wire works OK in the factory location but with most major loads under the hood being so close to the battery it. Cannot sense a large drop inside the cab.