Battery reads 17v prior to startup. 16.4v while running(voltmeter). 10v on the cluster gauge. Normally would read 13.5v. Car runs fine and idles smooth.
Ideas/suggestions????
Battery reads 17v prior to startup. 16.4v while running(voltmeter). 10v on the cluster gauge. Normally would read 13.5v. Car runs fine and idles smooth.
Ideas/suggestions????
Randy English
NASA Texas --> Rocky Mtn Region
CMC #77 Camaro
Buy a FORD! Hahaha
'86 Mustang Coupe - CMC2 34
I knew it was coming. I would but they aren't selling season passes.
Randy English
NASA Texas --> Rocky Mtn Region
CMC #77 Camaro
17 Volts?... wow... sure that is not 12?... Lately I found it easier to read a volt meter with my new reading glasses...Originally Posted by rleng1
I'd say borrow a meter to cross check.
Dave Balingit
NASA RM Regional Dir
Or, just add some ballast. Being light means the electrons don't have as much work to do through the ground so the voltage runs a little high.
#39 CMC Camaro
Orange is Fast!
CMC-NT01 FTW!
Don't listen to Dave... he's a little light himself... light in the head...
why did i bother????
Randy English
NASA Texas --> Rocky Mtn Region
CMC #77 Camaro
Randy - I would guess you have a bad voltage regulator on the alternator and maybe a bad cell in the battery to boot. I'd take both down to your local Autozone and have them tested before spending any money though.
If you still have most of the factory wiring harness and ignition key, turning the key to "on" with the motor off will display battery voltage on the stock gauge. Once you start the motor, it shows alternator output. If your battery is truly overcharged, this would explain the low 10v reading with the motor running - alternator output would drop while the system tries to stabilize itself.
2012 NASA-TX American Iron Champ
AI #29
Things to keep in mind.
A "12 volt battery" will never have more than 2.24v per cell. A car battery is a 6 cell battery. It can never put out more than 13.44 volts total. Once the car is running the alt will change that reading (system voltage) to whatever the alt is putting out. I don't think a good alt will put out more than 16 volts. If it does (as Casey said) the regulator is bad. So w/ the car off and the battery is putting out alot less than 13.4 volts (10 is alot less), this points to a shorted cell. W/ one cell not putting out it's share of 2.24v per cell (5 cells now) you will at best see 11.2 volts. Using 2 volts per cell for a battery that has been sitting (normal) you get the 10v you see now.
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