electrical issues

[dart custom]

i needs some help with my 72 dart custom
it only starts in in nutral, im thinking its the key ignition, and head lights dim when i let off the gas, i cleaned all the conetions and ground from battery to body, the altinator is good, im thinking the battery is not good enough but it reads 12.8 not running need help thanks.

 

[Beatnik]

Pull the yellow lead off the starter relay that's your ignition lead and check with key and a test light. Try in Park and Neutral. That'll rule out that. Could also bypass your NSS with a jumper and test it. Dim lights at idle are pretty common on these old cars. But wouldn't hurt to put a multi on it in the usual areas to see if your getting voltage drop anywhere. Test at the alt stud, regulator, across battery posts etc and see what your getting. Should all be pretty consistent and a good reading is between 13.8 and 14.4 volts. Any lower and your discharging, any higher and your over charging and will eventually cook your battery. 12.8 not running is neither here not there, just means the battery basically has a full charge at about 12volts.

A good option is relays for the headlights. Big upgrade to the old electrical system. Search crackedback (aka Rob). He sells a nice kit.

Good luck! I'm no electrical wiz, hopefully Rob or someone else has useful info for ya

 

[krazykuda]

Could your transmission linkages need adjusting. If it won't start in park, then they may not be adjusted properly.

 

[krazykuda]

Should all be pretty consistent and a good reading is between 13.8 and 14.4 volts. Any lower and your discharging, any higher and your over charging and will eventually cook your battery. 12.8 not running is neither here not there, just means the battery basically has a full charge at about 12volts.

When I used to test charging systems in Sears Garage, we used minimum of 13.3 volts to maximum of 15.0 volts when testing alternators/regulators.

12.4 volts or more for a statically charged battery. 12.8 is fine.

How well does it respond to a load. Put a volt meter across the battery negative and positive terminals and crank the engine over. It shouldn't drop below 10 volts under load, or the battery is bad.

 

[RedFish]

If it starts in neutral everything electrical is working. Fault is mechanical adjustment of shifter linkage.