Hey guys. I have a 1978 F-250 and I have two major electrical problems I need help with.

First, my alternator does not charge my battery. It is a brand new alternator, and I have tested my battery which is also good. (I also have a new voltage regulator installed.) Any ideas on what could cause this problem?

Also, when I turn on my headlights, they flicker along with my running lights and dash lights. The rear running lights and my tail lights do not come on like they should either, but the brake lights and turn signals still work fine. (same bulb) I have checked all the bulbs, which seem to be fine.

Any help is much appreciated. Thanks in advance.

 

Welcome to FTE!

Most likely the new voltage regulator or alternator are bad out of the box, or have failed prematurely. This is not unheard of. You can have both the alternator and regulator tested at many parts stores. There could also be an issue with the wiring - as a first step, make sure the fusible link between the alternator output and battery post of the starter solenoid has continuity. You'll also need to check for keyed power at the voltage regulator - does this truck have an ALT light, or an ammeter gauge? For these last two tests, you'll need a multimeter.

The flickering headlights is often indicitave of a voltage regulation issue - often because of a bad voltage regulator, or ground shift at the voltage regulator. It could be related to the charging issue. I'd solve the charging issue first - if the headlights still flicker once the charging problem is solved, then try running a jumper wire from one of the regulator mounting bolts to clean, unpainted metal on the engine (ground). If the problem improves, then the inner fenderwell is not properly grounded because of a faulty or missing ground strap.

Power to the tail lights is the BROWN wire. Start at the socket, and trace upstream to see where power might be getting cut off.

 

did you flash your regulator corectly?

i replaced the regulator on my galixie after it had sat along time, i got 3 that were bad from napa strait out of the box and i didnt flash the 4th corectly, if its bad or improperly flashed the alt. light on the dash will stay on until you physicly push the the "batt" coil point closed, or you disconect the batery cable. someone corect me if i am wrong but if i remember right thats how it happened

 

What do you mean by "flashing" the regulator?

There's no procedure to get a regulator to start working. They perform one simple function, and they do it as soon as they're put to work.

If you're referring to "flash" as in flash memory, like an ECU, there's no such thing inside.

 

sorry when i say flash i mean polorize you cross the positive terminal with another terminal temporarily to tell it how to charge...........i may be reffering to older techknolegy this was on a 63 ford galixie but the reg looks the same as whats in my truck.

 

Thanks for the help. I am going to take my battery, voltage regulator, and alternator to Napa soon to get them tested. I will let you guys know what I find.

 

You probably have a bad fuseable link. Never heard of flashing an alternator. Welcome to the forum.

 

Ah, now I know what you're talking about. Polarization is for vehicles with generators, which doesn't apply here. The generator is actually what gets polarized, not the regulator. Alternators do not need to be polarized.

 

I would check grounding both for the battery and engine. The battery should be grounded to the chassis as well as the engine. Usually through a strap from the chassis to the engine.

 

ahhhhhhhhhhh fiddle sticks i totaly forgot about it haveing a generator lolol sorry bout the confusion guys

 

I took the alternator into Napa, and they put it on their machine. It was bad! They are going to replace it at no charge, but they didn't have it in. I am picking it up tomorrow morning and having them put the new one on their machine just to double check. Hopefully this will solve my issue.

Thanks again for all your guys' help!

 

I got the new alternator which fixed my problem with charging the battery, but I still have the problem with my lights. I am going to check all my grounds and connections. Any specific place I should check first?

 

Refer to my first post in this thread.