70 amps alternator wire question

[UslAura1]

alright i’ll look at it this week, it sparked a little bit when i was removing the nut that holds the wire when i removed the alternator, also noticed that both batteries indicate 14 volts when the truck is running, but when the key is at the off position, i only have 12.6 volts on the driver side battery, the passenger side battery doesn’t show any on a volt meter

 

[Nero]

14v charging and 12.6v are very healthy numbers.
The battery on the passenger side is flipped, just want to make sure youre putting the leads on correctly?

 

[UslAura1]

Yeah i made sure they were on the good poles and it doesnt show any voltage

 

[IDIBRONCO]

Maybe you've found the problem. It may be a bad battery. They do need to be replaced as a pair. The weaker one will draw down the better one if you don't replace both.

 

[UslAura1]

Alright i’ll look to it and keep ya updated

 

[UslAura1]

Hey, i looked at the voltage of my batteries before starting it, didn’t use it for 2 days and they were at 12.78v both of them. And when charging they’re still at 14 volts. But i noticed that for a couple minutes after starting it my ampmeter still goes up and down with the rpm of the truck, and i don’t know if it’s linked but my cab lights up top flicker too.

 

[franklin2]

Like was said, 14 volts is good when the engine is running. Charging more or less when you rev the engine is normal, the alternator puts out more power when it's turned faster.

If you are sitting there at a constant rpm, and the lights are flickering, then that is usually a bad connection with the small wire plug on the alternator. Those slide on connectors like to spread out and get loose after years of vibration from the engine. If you can tweak them a little bit to close the connector up, and still be able to slide it on the alternator, that usually will fix a flickering voltage problem. Also make sure the terminals are clean.

 

[UslAura1]

Alright i’ll look at it tomorrow, diselectric grease helps too i believe?

 

[IDIBRONCO]

If you are sitting there at a constant rpm, and the lights are flickering, then that is usually a bad connection with the small wire plug on the alternator.

Or, possibly, the glow plug controller is after glowing. That draw would dim the lights and make the needle on the voltmeter ( I think that's what the 1992s have) jump up and down for a few seconds.

 

[UslAura1]

Yeah it does that with the glow plugs i don’t know why, but when it stops the meter still follows the rpm, i know it’s not only the gauge since the lights in the dash does the same too

 

[Nero]

Alright i’ll look at it tomorrow, diselectric grease helps too i believe?

Dielectric grease does NOT conduct electricity. It is actually an insulator. Common misinformation.

Sounds like you are on the right path, flickering lights could be a poor ground too. Check the block grounds and cab grounds.

 

[UslAura1]

Does someone have a diagram with the ground’s locations?

 

[IDIBRONCO]

Dielectric grease does NOT conduct electricity. It is actually an insulator. Common misinformation.

That's funny since I put it inside the spark plug boot on a four wheeler to help keep water out. It always runs fine.

 

[Nero]

That's funny since I put it inside the spark plug boot on a four wheeler to help keep water out. It always runs fine.

That is typically the only place you're supposed to use dielectric grease, helps prevent arcing from the lead to the ground side of the spark plug.

 

[ttman4]

Dielectric grease does NOT conduct electricity. It is actually an insulator. Common misinformation.

Sounds like you are on the right path, flickering lights could be a poor ground too. Check the block grounds and cab grounds.

I like Dielectric grease cause it sorta helps keep that green green crud out/away from my electrical wiring, be it automotive, shop wiring, extension cord plugins, just whatever.
Even Carol uses it on her coffee pot I think!
No seriously, there's a place for using Dielectric Grease.