Very Confused!
The shop that restored my '68 FS FB put an O'Reilly alternator and VR on the car. It bounces between 15 and 16V essentially all the time. I replaced the VR with an older chrome unit I had, and it was more steady in the 14 to 15V range. I would prefer steady voltage, but not sure that is the case. The O'Reilly alternator was a new Chinese knockoff of the Chrysler alternator. I would prefer the Chrysler unit with new bearings and diodes, but as long as this one works, I will keep it.
The VR can be checked for both function and approximate voltage regulation by using an ohm meter as per this video: The O'Reilly VR had 2.6 ohms across the pins and regulated too high. The replacement chrome box had 1.75 ohms resistance and was fine.
I would ground the alternator to the engine and run at least a 14-gauge ground wire from the VR to the back of the block just to be sure both are grounded properly. That is how the VR gets it voltage signal to regulate the output.
I made a mount for the electronic VR that bolted to the '68 firewall using 1/4" aluminum sheet stock cut to the dimensions of the electronic VR. Holes were drilled and tapped for 1/4-20 bolts. I used an old mechanical VR to determine the holes for mounting the adaptor bracket and used countersunk bolts to flush mount the aluminum plant to the firewall. The electronic VR bolted up fine, but the lower bolt was difficult to install due to clearance with the inner finder. A stud here would solve that issue.
The shop that restored my '68 FS FB put an O'Reilly alternator and VR on the car. It bounces between 15 and 16V essentially all the time. I replaced the VR with an older chrome unit I had, and it was more steady in the 14 to 15V range. I would prefer steady voltage, but not sure that is the case. The O'Reilly alternator was a new Chinese knockoff of the Chrysler alternator. I would prefer the Chrysler unit with new bearings and diodes, but as long as this one works, I will keep it.
The VR can be checked for both function and approximate voltage regulation by using an ohm meter as per this video: The O'Reilly VR had 2.6 ohms across the pins and regulated too high. The replacement chrome box had 1.75 ohms resistance and was fine.
I would ground the alternator to the engine and run at least a 14-gauge ground wire from the VR to the back of the block just to be sure both are grounded properly. That is how the VR gets it voltage signal to regulate the output.
I made a mount for the electronic VR that bolted to the '68 firewall using 1/4" aluminum sheet stock cut to the dimensions of the electronic VR. Holes were drilled and tapped for 1/4-20 bolts. I used an old mechanical VR to determine the holes for mounting the adaptor bracket and used countersunk bolts to flush mount the aluminum plant to the firewall. The electronic VR bolted up fine, but the lower bolt was difficult to install due to clearance with the inner finder. A stud here would solve that issue.