Dropping voltage as accessories are added

[Helirich]

Might be time to get LED headlights. (And side lights) It would be nice if everything on reads 12.6+ at idle, but you will probably be fine as is.

[Timeless]

Might be time to get LED headlights. (And side lights) It would be nice if everything on reads 12.6+ at idle, but you will probably be fine as is.

Agreed. Every exterior light on my car is LED. Holley Retro Bright LED headlights are amazing.

[81dmc]

I had the issue on my car too. Best way to fix this is to add the sense wire to the alternator. Then it uses the auxiliary relay output as the voltage reference and bumps up voltage at the alternator….

I saw around 14v on my cluster after I added that wire.

[82DMC12]

I had the issue on my car too. Best way to fix this is to add the sense wire to the alternator. Then it uses the auxiliary relay output as the voltage reference and bumps up voltage at the alternator….

I saw around 14v on my cluster after I added that wire.

I'm using the one-wire alternator (Delco) from DPI. Isn't that wire the "sense" wire? As part of my testing, If I disconnect it and start the car, the voltage is quite lower and my LED's in the instrument cluster start to flicker because they aren't getting enough power. I think the battery light is also illuminated when this happens.

[David T]

The electrical system is designed so that at idle the battery can assist in supplying the loads. The car is not meant to idle for any length of time with ALL the loads. Especially since the alternator can't produce it's full, rated output at idle. As long as the system voltage doesn't drop below 12 volts it is OK. The voltmeter in the dash is not all that accurate anyway so if you have any concerns you should hook up an accurate voltmeter and the best place to measure is on the battery terminals. If you do drop below 12 volts you should check and test the battery and it's connections (or maybe not idle so long with all of the loads on). If the system drops below 12 volts the motor will start to run badly and if it gets too low it will stop.

[82DMC12]

I bought this little guy so I could monitor my voltage from a second source while driving the car. Works great.

https://www.amazon.com/dp/B085LKLCYX...roduct_details

[81dmc]

I'm using the one-wire alternator (Delco) from DPI. Isn't that wire the "sense" wire? As part of my testing, If I disconnect it and start the car, the voltage is quite lower and my LED's in the instrument cluster start to flicker because they aren't getting enough power. I think the battery light is also illuminated when this happens.

Mine was supposedly “one wire” as well. Thing is, these cars do have quite a voltage drop. Also, a few years ago, someone on here found out that the flashing battery light when the ignition is turned on is caused by having the sense wire disconnected.

On my early car at least, there was already a sense wire present at the bulkhead. I simply tied that to the alt and bam, full voltage at idle.

[Timeless]

The electrical system is designed so that at idle the battery can assist in supplying the loads. The car is not meant to idle for any length of time with ALL the loads. Especially since the alternator can't produce it's full, rated output at idle. As long as the system voltage doesn't drop below 12 volts it is OK. The voltmeter in the dash is not all that accurate anyway so if you have any concerns you should hook up an accurate voltmeter and the best place to measure is on the battery terminals. If you do drop below 12 volts you should check and test the battery and it's connections (or maybe not idle so long with all of the loads on). If the system drops below 12 volts the motor will start to run badly and if it gets too low it will stop.