Charging issues Please help

[lincscbb86]

After it runs awhile, the car will not start. Its almost like I can watch the volts drop. The battery is located in the back. Grounded to the quad shock mount. I also have the original ground in the front. I have a new alternator that is suppossed to be 130amp. All I have running is the fan controller and Ramchargers fan. Alternator was check and it is fine. New Optima red top, newstarter, new ignition switch(the one under the column). I cant seem to figure out what the problem is. Does this sound like a ground problem? All wire from the battery to alt. is 2 gauge. From cut off switch to solenoid is 1/0 welding cable. I also have u/d pullies. Thanks

 

[wyominghotwheel]

i would move your actual battery ground from the quad shock to the frame. Besure you have a ground from the front of the block to the frame and the little ground strap that goes from the motor to the body..........

hotwheels of insanemustangs

 

[HISSIN50]

After it runs awhile, the car will not start. Its almost like I can watch the volts drop.

please explain this phenomenon further.

when it wont start, the solenoid wont click or anything?

if you turn on headlights, do they illuminate brightly?

what does your handheld DMM tell you when you check it at the battery vs alternator vs solenoid? lookin for voltage drops here.

I have used jumper wire to augment existing grounds (or power cables) to see if additional cable helps an issue - this is a quick and dirty way to check any given cable to see if it is overburdened or insufficient.

good luck.

 

[Zero_chance]

If you can watch the volts drop that sounds like the alternator isnt supplying any voltage to your car.

 

[jrichker]

Rear mounted battery ground wiring. Follow this plan and you will have zero ground problems.

One 1 gauge or 1/0 gauge wire from battery negative post to a clean shiny spot on the chassis near the battery. Use a 5/16” bolt and bolt it down to make the rear ground. Use a 1 gauge or 1/0 gauge wire from the rear ground bolt to a clean shiny spot on the block.

One 4 gauge wire from the block where you connected the battery ground wire to the chassis ground where the battery was mounted up front. Use a 5/16” bolt and bolt down the 4 gauge engine to chassis ground, make sure that it the metal around the bolt is clean & shiny. This is the alternator power ground.

Crimp or even better, solder the lugs on the all the wire. The local auto stereo shop will have them if the auto parts store doesn't. Use some heat shrink tubing to cover the lugs and make things look nice.

The computer has a dedicated power ground wire with a cylindrical quick connect (about 2 ½”long by 1” diameter. It comes out of the wiring harness near the ignition coil & starter solenoid (or relay). Be sure to bolt it to the chassis ground in the same place as you bolted the alternator power ground. This is an absolute don’t overlook it item for EFI cars

 

[lincscbb86]

Alternator is not charging properly. I checked voltage at batt,11.5 volts. At alternator, 11.5 from batt., 5 back to batt. Is this alt. bad? Or do I still have a ground problem? All grounds have been checked and are tight.