Happy Holidays All! I pulled the engine last year for a general overhaul (long story). While it was out, I cleaned up the engine bay. I put it all back in last week and it runs superbly. Couldn't be happier....BUT. Here's my issue: When the engine's running, shouldn't I see 14.5-ish volts at the battery terminals? I'm only getting 12.7ish, which I get with the motor not running as well.
I did my best to check that the wiring is all plugged in i think... I replaced the alternator. Just 12v, No 14v. I replaced the Voltage Regulator with a solid state version from AMES. Just 12, not 14v. I'm beside myself...I dont get it! All thoughts are welcome!
RG
'68 400HO Coupe, 4 spd, 259 interior, Windward Blue. My other car's a Johnson 15 outboard on a '61 Starcraft rowboat... Just sayin'.
Are you sure your engine is properly grounded? If there, for example, is paint where the ground cable connects to the head, the ground connection can be compromised. One way to test this is to connect a jumper cable between the battery and a good ground on the engine (in parallel with the stock ground cable), maybe on the alternator itself, and see if your voltage changes.
should have a good ground. Even have a dedicated ground from the VR mounting foot to the body via pigtail. I just discovered that I'm not getting 12v to the VR plug at the red terminal. Wondering if that little red wire, which looks squirrely-twisted is a fusible link? ( looks downsized from the incoming 12v...looks like it goes from 12 to 16 awg.)
'68 400HO Coupe, 4 spd, 259 interior, Windward Blue. My other car's a Johnson 15 outboard on a '61 Starcraft rowboat... Just sayin'.
What's the voltage at the back of the alternator on the lug.
I agree, if you painted any where there is a ground that could be your issue.
If you have the same voltage at the back of the alternator (12.7 ish) run a jumper from the alt case to the battery negative terminal. If it's charging find the bad ground. If not, you got a bad alternator out of the box. Not uncommon at all.
I've tested the 4-spade plug that goes into the regulator. I get battery volts at the #4 brown when key is on, batt volts at #3 red when on or off, A little less than battery on the #2 blue when key is on, and 0 on the blk/white #1 terminal when key is on or off. Why would the blk/white wire always be dead? What's that reading supposed to be? Is there a fuse somewhere on the blk/white wire?
PS: Just jumped the alternator over the VR. Gave the Alt straight 13.8v from the batt with engine running. Then the alt produced 17 volts to the battery. (Disconnected the direct feed quickly.) So the alternator certainly makes power...gotta be either the VR (which is new) or maybe that blk/white "R" wire? This is making me nuts-
Last edited by ReverendRW; 12/29/2302:23 PM.
'68 400HO Coupe, 4 spd, 259 interior, Windward Blue. My other car's a Johnson 15 outboard on a '61 Starcraft rowboat... Just sayin'.
As a testament to "Dont assume your new part is perfectly good":
After at least a month of "brain burnout" struggling, not sleeping, frustrated beyond healthy, nearly rewiring the front end, continuity testing everything, searching for blown fuses, external bench testing with dedicated wires, simulations, etc!!!!, my brother-in law thought two of my pictures looked funny. The wire colors didn't make sense to him.
Turns out that when I replaced the grey alternator input plug, the blue and blk/wht wires in the pug had been reversed when it was assembled. I didn't think to check if the factory did it right! That never crossed my mind, or anyone else's for that matter!
So check out the pics. I pulled the pins from the plug, and re-inserted them correctly. It took 30 seconds. I'm making a pure 14.4 volts at the battery!! And sleeping again!
Smokey burnouts! R~
'68 400HO Coupe, 4 spd, 259 interior, Windward Blue. My other car's a Johnson 15 outboard on a '61 Starcraft rowboat... Just sayin'.
