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.
Posts: 1,254
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.
Location: FL
Posts: 948
My VIN: Early
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.
Early 81 5spd conversion- DMCH Ground Effects, Double Din, Custom Instrument Cluster, QA1 Suspension, 3.0 PRV with MS3
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.
Andy Lien
VIN 11596 Jan 1982 build - owned since Nov. 2000!
Total frame-off restoration completed 2021-2023
Photography and Backpacking is life.
Was Fargo, ND
Now Kansas City
Location: Northern NJ
Posts: 8,583
My VIN: 10757 1st place Concourse 1998
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.
David Teitelbaum
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
Andy Lien
VIN 11596 Jan 1982 build - owned since Nov. 2000!
Total frame-off restoration completed 2021-2023
Photography and Backpacking is life.
Was Fargo, ND
Now Kansas City
Location: FL
Posts: 948
My VIN: Early
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.
Early 81 5spd conversion- DMCH Ground Effects, Double Din, Custom Instrument Cluster, QA1 Suspension, 3.0 PRV with MS3