DodgeCharger.com Forum

Mopar Garage => Electric, Gauges, & Lights => Topic started by: 66FBCharger on November 14, 2019, 08:01:20 AM

Title: Alternator discharging
Post by: 66FBCharger on November 14, 2019, 08:01:20 AM
I went to drive my 69 Charger R/T to the next town last night to put it in storage for the winter. It was dark so I had my parking lights on while the engine warmed up. The ammeter showed -20A. If I revved the engine it would go up to +20 but not consistently.
I checked for loose grounds. They all seemed good. Connections are tight. I don't see anything obvious. I am planning to change the electronic regulator with a new one I have.
What am I missing? How do I check the alternator on the car? With a test light should I get a pulsing light at the field? I get a solid light from the test light.
Thanks in advance for any leads for stuff for me to check.

Title: Re: Alternator discharging
Post by: 73chgrSE on November 14, 2019, 03:25:26 PM
When mine went bad I plugged a meter up to the battery with the car off and see if you get 12v. then start it up and see if it goes up to 14 or so.
Title: Re: Alternator discharging
Post by: Nacho-RT74 on November 15, 2019, 11:57:11 AM
don't confuse what ammeter reads with volts rates... they are in relation but not allways a straight out relation
Title: Re: Alternator discharging
Post by: 66FBCharger on November 15, 2019, 12:44:12 PM
I am hoping to look at it this weekend when it is light out. I have a feeling the voltage regulator is bad.
Title: Re: Alternator discharging
Post by: Nacho-RT74 on November 16, 2019, 06:15:35 AM
BTW, the alternator is not the one discharging... is the battery ;) . The alternator can't get discharged because is not an accumulator, is just able to source the car allong with recharge the batt or not. Read the stickied thread on top of this section to understand the ammeter readings ;)

it is pretty much normal get a discharge reading on old Mopars while idling with lights on. NOW, how much of that is normal? well, depending on your wiring conditions. The voltage can go throught a hair while amperes if don't get a good path are able to heat up everything and this increases failures.

at certain point, when amperes are not good enough, voltage rate can be decreased, but when this happens is already late somehow. The fail began way before. Time to check your wiring and terminals. They need to be mantenienced just like brakes, suspension etc.

another deal you can be getting is a diode went bad into the alternator.
Title: Re: Battery discharging
Post by: 66FBCharger on November 18, 2019, 09:25:52 AM
Thanks for the reply Nacho.
I found the issue. The terminals are burnt/ melted at the bulkhead connector.
The big question is, how do I repair it or bypass it.
Title: Re: Alternator discharging
Post by: Nacho-RT74 on November 18, 2019, 06:48:23 PM
Check the stickied thread