I am stumped! I have installed 3 NEW alternators, replaced the batteries, checked the battery grounds, fuses, cleaned terminals.....I am still losing voltage as I drive. I seem to get charging voltage when truck is cold, then as engine warms, all charging voltage disappears....and I run off battery. Electric Gremlins in a major way.
HELP?!? I don't know where to go from here.....

 

Do your batteries go dead when you drive? Where on the Volt gauge does the needle go when it warms up?
------------Jeremy

 

Jeremy -

as I drive, the volt meter contiuously drops.....on a long drive several days ago, I lost turn signals, lights, wipers, basically all power. I cannot definitely say that it is a cold engine/warm engine distinction, though it does randomly 'charge', then not charge....more not charge than anything. Currently the volt meter is on the left part of the letter 'n' in normal.....

 

did you change the solinoid? maybe it is sticking or check the starter take it out and have a look or get it checked I have had worn out starters do the very same thing you are explaining good luck

 

Starter???

Nope, haven't touched the starter.....I recently had a new tranny put in.....prior to that I pulled the dust cover off the starter flywheel, and all teeth on it looked good....as the truck starts just fine, I hadn't even thought of checking the starter.....I will take a look at it again though. Just seems hard to think that would cause voltage loss problems while the truck starts just fine....

 

Check the wiring going to the plug on top the alternator. It's the connector that everyone lays on when working on the engine, the wires get damaged. Wiggle them with the engine running, if it starts charging you will hear the alternator strain, or use a volt meter on one of the batteries.

Have you had the "New" alternator checked before it's installed? the seller should be able to do this for you. Did you have the bad alternators checked to see if the were indeed bad?

There are 2 fusable links that may cause these problems. They are located near the starter relay. They are 12 gage, Grey in color. The wires going to the first in line is Black w/ Orange tracer, the other is Yellow w/White tracer.

 

Cuda -

went out this morning and fired the truck up....sure as shootin', while cold, it was throwing out 14.2 volts.....drove it down the street about .5 mile, and the guage dropped....got home, tested again, and it only had 12 volts. My understanding of the fusible link is that it would not work, period, if it were melted. I also clipped the stator wire and re-connected it to the other plug on the alternator. What I have not done was go to the dealer and get new clips for connectors for the alternator. Still, why charge when cold and not when GP's stop warming? Could it be some kind of ignition problem?

Scott

 

That's a mystery, If you need the factory trouble shooting procedure send me a PM with your email address, I'll send you some info. Yep, that's my understanding of fusable links. They are just a wire with a smaller wire soldered inline. Maybe when they blow it can still make contact, IDK? Did you wiggle them after it began discharging.

BTW: What vehicle, alternator do you have? There are 2 charging systems. Standard and 215 Amp.

Has the wire harness under the hood been modified ie. sound system amplifier ect?

Did you just replace the other alternaors without bench testing?

 

Hey Cuda -

'96 F250 7.3L....if you could send the trouble shooting info that would be great. Also, anything on replacing glow plugs and injectors (don't need to now, but would be great to have when time comes).

Got it solved, btw. This is really really stupid, too. I took apart the dash a while back to replace some burned out bulbs. Turns out that the battery light wiring harness did not get completely seated in the plug. I subsequently was driving in Denali National Park (bad gravel road), and that plug jiggled loose. So, the battery indicator light is part of the charging circuit. Needless to say, the circuit wasn't closed, so no charging. Whoodda Thunk!?! Well, at least now I have an Autolite alternator with a lifetime replacement
I am tempted to take the batteries back to Costco however.

Thanks again for all the help!

My email is scsak067@gmail.com

Scott in Alaska

 

Click...here....

 

I'd keep the batteries the bigger and newer they are the better off you are when it gets cold out. I have 2 1000CA from walmart only 2 years old. I couldnt imagine having anything less in the winter.
-------------Jeremy

 

Glad you found it, that would have been a tough one to help you with here. They usually are anyway, intermintant electrical problems are a biatch.

Action, Rick, has you covered on the info, if you need something specific let me know.