cyrus77

iTrader: (4)

81 Formula, both alternators do not work. The batteries read 12.11 volts while off. Running they pull it down to 12.02 volts. Both alternators seems to be doing nothing. I took them to 2 different auto stores and they were not able to check the alternators due to not being able reference a vehicle (ford 1994 etc..). Any ideas to get these tested? Or know what the problem is.
Thanks,

Cyrus

cyrus77

iTrader: (4)

I took it to another auto parts and their COMPUTER cant do it either this is ridiculous.

AllDodge

iTrader: (1)

I am assuming that you have a Mando style alternator. If this is true there are 4 connections needed for the ALT to work. The Orange is the charge lead which goes back to the battery via the starter connection. The red/Purple is always hot along with the Orange. Red/Purple comes from the main breaker on the engine. The purple wire is the excitation lead, and then there is a ground.



To see if your ALT is working, first see if you have 12V on the Orange and Red/Purple wires. If 12V is present, turn key to run and see if 12V becomes present when key is turned on. Make sure there is a ground connected to the ALT. If all is good, the ALT should work with the engine running, if not take it to a rebuilder and they can usually rebuild for under $40. Or buy the parts your self and do it, not hard, just remove and replace bearings and diode packs/regulators.

With your ALT not charging it would be normal for the voltage in the battery to drop a bit by the engine using it to run.

snapmorgan

iTrader: (2)

Those jip joint auto parts stores are a joke. There is an alternator/starter shop in almost every town. Take them there and the will fix you up.