Question about voltage (1 Viewer)

[jralph125]

Hey all,
Had been having voltage issues for awhile now, battery wasn't charging, misfiring, plugs fowled etc etc. Anyway, I have replaced the alternator and voltage regulator (which I discovered melted down). Can anyone tell me what type of voltage numbers should I be seeing coming off of the alternator while running? Right now I am getting around 13.20V, is that a normal range or is that low? Still having some small issues trying to narrow down the problem. Please help, thank you

 

[1969FJ]

Testing battery and charging system

 

[JackA]

That's about right. Rev the engine and it should go up to about 14 volts.

 

[4x4veteran]

13.2 will work but in my opinion it should be closer to 14V. Check belt tightness and grounds. Do you have a good ground from engine to frame and body? Good cables and connections are a must.

 

[Pin_Head]

It depends on the charge state of the battery. 13.2 is normal if charging. 13.8 is normal if the battery is charged.

 

[jralph125]

It depends on the charge state of the battery. 13.2 is normal if charging. 13.8 is normal if the battery is charged.

Hmm Interesting, didn't know that....I will check

 

[jralph125]

13.2 will work but in my opinion it should be closer to 14V. Check belt tightness and grounds. Do you have a good ground from engine to frame and body? Good cables and connections are a must.

Ok, ty....Have new cable on power side, I will check the ground side. Where should it ground to? Mine grounds to the alternator bracket on the block

 

[1911]

Ok, ty....Have new cable on power side, I will check the ground side. Where should it ground to? Mine grounds to the alternator bracket on the block

Not sure what bone stock is, but more than one is good. When I installed my 200-amp Mean Green alternator, I used heavier gauge than stock (welding cable) and ran one from the alternator to clean mount on the block, one from the alternator to the frame, and another from the starter to the frame.

 

[4x4veteran]

Not sure what bone stock is, but more than one is good. When I installed my 200-amp Mean Green alternator, I used heavier gauge than stock (welding cable) and ran one from the alternator to clean mount on the block, one from the alternator to the frame, and another from the starter to the frame.

IMO with DC voltage you can't have to many good grounds. Ground from the bat to block is good for starter performance but if ground is weak going to frame and body then other component performance can be compromised. Back when I was a younger lad I had a Fiat that had a cable going to the clutch lever. I couldn't figure out why the cables kept failing. Turned out the battery was grounded to the body but there was no ground strap to block so every time I started the car the ground would go through the clutch cable causing it to heat up at points of contact thus weakening it till it broke. Electricity will take the path of least resistance. If there is a bad ground on one item the electricity will some times ground through another, occasionally not with the best results.