charging problems....still!!!!!!!!!!!

[grizwald]

tried another alternator, still charges relatively low. with no fan or water pump running right when i start the car it's around 13.5V. turn on the w/p and fan and it drops to around 12.5V or so. if i turn on anything else, it drops to 12V or less. even the turn signals flashing makes the voltage drop. any thoughts as to what might be causing this? i thought maybe a bad ground, but i'm not sure. i have a ground from the battery to the frame (rear of the car), a huge ground strap from the block to the frame, and recently added a ground from the body to the frame.

 

[Anonymous]

is your battery in the trunk?

if so what are running from the alternator to the battery to charge the battery?

i had a problem like this until i ran a #4 cable from the alternator to the battery.

not from the alternator to the remote solenoid but straight to the battery.

solved my problem

 

[Goob]

Pulley sizes?
Good ground connections through all the brackets, intake, etc?

 

[grizwald]

i changed my alt wire from being about 10-12 guage to being 4 guage front to back. the pulley size could be a concern. it's a stock crank pulley...somewhere in the 7" diameter range.

as far as grounds...i have only got the one big strap from the engine to the frame. as i mentioned, i grounded the battery at the back of the car to the frame. i have one other ground wire from the body to the frame. is that enough or should i be adding more elsewhere?

 

[Goob]

Are those chassis grounds to a stud welded to the frame, or just bolted up?

13.8 to 14.2 volts is great on the charge voltage, but it sounds like it is weak on output amperage under load.

You need to break it down with an inductive meter to measure the actual amperage output along the line.

 

[grizwald]

the grounds are just bolted up.

 

[Goob]

To ensure quality connections, the best would be a ground cable from the battery to the engine block, but that is overkill, in my opinion, but I would, (and do) have a stud welded to the frame at the front and rear to connect the cables to, a cable to the block, and some ground straps or at least 10 ga. quality wire to at least one of the cylinder heads, and of course to the body for all the other accessories, lamps, and grounds.
Make sure your alternator mount is bolted clean to a well grounded bracket mount, last but not least, check the output of the alternator under a load.....you'll need access to a VAT machine or a good bench tester with a load inducer.

 

[grizwald]

i'll try a couple extra grounds when i get a chance. i don't have the engine grounded to the body...just to the frame. so i'll put one to the fire wall and see what that does.

thanks for all the advice.

 

[injected]

Are those chassis grounds to a stud welded to the frame, or just bolted up?

13.8 to 14.2 volts is great on the charge voltage, but it sounds like it is weak on output amperage under load.

You need to break it down with an inductive meter to measure the actual amperage output along the line.

x2 and the generator could be only charging 2 phases!

 

[Supe]

After going through the same issue, it turned out to be yet ANOTHER busted Optima battery (#6 now, never again).