help!!! charging problem

[boostmobile]

ok here it goes.
my 86 gn stopped charging while I was driving and it ran off of the battery until it finally died on my way home. so I had it towed back home.
I removed the old alternator and brought it to advance auto parts and had it bench tested. they said it was dead. so I bought one off of one of the locals which did not charge either had that one bench tested also. so I just got my new alternator today, installed it with a new belt and when I jumped it it was only reading 12.5v at the battery and shortly after I removed the jumper cables it would just stall out.
so I removed the new alternator and brought it back to advance auto parts and I watched them bench test it and it was good. so I brought it back home, put it back in, belt nice and tight and it still only reads 12.5v at the battery and dies as soon as the jumper cable is removed.

the only mod that I have related to this is a fuel pump hot wire. and gauges.

any help would be awesome. I dont know what else to do.

 

[Westriver87]

I would check the voltage at the alternator and check all the grounds. You probably killed the battery and need a new one or it may just need charged if it will hold a charge.

 

[boostmobile]

oh, wait!!!!!!! that same day I noticed that my volts light stopped lighting up when the ignition is on. could that volts light circuit have something something to do with it? I just assumed the bulb died. the battery is good.

 

[Jerryl]

oh, wait!!!!!!! that same day I noticed that my volts light stopped lighting up when the ignition is on. could that volts light circuit have something something to do with it? I just assumed the bulb died. the battery is good.

Depending on the set-up . . .
Light no workie, alternator no chargie. :tongue:

Other options:
Caspers field fix
Set-up with resistor accross the light bulb

 

[boostmobile]

thanks, I think youre right

Depending on the set-up . . .
Light no workie, alternator no chargie. :tongue:

Other options:
Caspers field fix
Set-up with resistor accross the light bulb

 

[boostmobile]

thanks jerryl, problem fixed!!!!!!!!

 

[Jerryl]

thanks jerryl, problem fixed!!!!!!!!

Glad it was and easy fix!

 

[G NASTY]

I'm having a similar problem, what was your fix?

 

[boostmobile]

I'm having a similar problem, what was your fix?

the volts dash light bulb was burned out

 

[turbojd]

the volts dash light bulb was burned out

And if that doesn't fix the problem, try Caspers "field fix kit" I have the field fix kit on my car just as a backup.

 

[Beamer]

What occurs here is the dash light bulb privides a value of resistance from +12VDC to the altinator to trigger the field to charge. If the light bulb filament is broken (hence - burned out - no workie), you do not get this resistive power trigger to the altinator. The caspers field fix is putting that value of a resistor in line with the (I think it is brown) wire that plugs into the altinator to always give the trigger to provide a charge. The value of the resistor is around here somewhere and I can find my pack that I picked up from Radio Shack if anyone needs it. I used a slightly higher value and added it so I can still have the function of the dash light. But if my dash light goes out and I do not realize it... I will still be charging. This is due to adding a resistor in parallel, the value drops below the lesser of the 2. If they are equal in size, they split in half. There is a formula - I just don't know it off the top of my head.

What you look for is with the key on and engine off... The volt/batt/ charge light should be on, until the motor is running and the altinator is charging.



Mike

 

[GNVenom]

The Field Fix is the easy approach and will bypass any wiring issues with the engine wiring. However, you should all educate yourselves:
http://www.installationinstructions.com/FYI/alternator_charging_tech.pdf

You're welcome...

 

[Beamer]

Very nice John, and THANK YOU !


Mike

 

[longball]

The Field Fix is the easy approach and will bypass any wiring issues with the engine wiring. However, you should all educate yourselves:
http://www.installationinstructions.com/FYI/alternator_charging_tech.pdf You're welcome...

excellent write up, VERY informative and a keeper!