Truck still seems like its not charging up... - Page 2

HBKCummins · 11-09-2009, 05:05 PM

i mean i think my starter is on the way out too...but the bottom line is my generator light is coming on and the alternator is not charging up while im driving.

__________________
1996 Ram 2500 5sp. fuel plate, intake, 4in. straight out, golden fuels 160gal. nomad system, 45 hp injectors.

MX26 · 11-09-2009, 05:25 PM

Well, take the charger back and swap it with a different one. Easiest way to eliminate that..

__________________
Trust me.... I'm a doctor.

94 12V NV4500 2wd - #100FF, BHAF, 3GSK, 4" FBD Straight
98 12V Quad Cab Shortbed SLT 4x4 - Auto with a "few" mods

illflem · 11-09-2009, 08:07 PM

There is a temp sensor, usually on the pass side under the battery but on some years it's on the driver's side that must have the bottom of the battery touching it.
If the sensor isn't touching the battery and it's below freezing the sensor can tell the computer the battery is frozen and won't let it charge.
Since you have oversized batteries it might be something to check.

__________________
Bill
'95 2500 4wd auto
'95 3500 5 speed heavy hauler
Not stock

E TEX RAM · 11-09-2009, 08:11 PM

Check the fuse in the power distirbution box. It should be 120A. If that fuse is blown, you won't get a charge at the battery.

If the fuse is good, check the output of the alternator. Using a volt meter attach the red lead to the B+ terminal on the rear of the alternator. It is the large terminal with the thick cable. Attach the meter black lead to ground. You should read 13-15 volts if the alternator is charging.

If the alternator is not charging, check the field. These are the two small terminals on the back of the alternator. The bottom is positive the top is negative. You should read 3-6 volts normal. Lower than 3 the PCM may be bad or the wiring. More the 6, the PCM VR is trying to get max charging out of the alternator. It means bad alternator.

Most often it is the alternator. You can have it bench checked.

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11-09-2009, 05:05 PM	#13 (permalink)
HBKCummins Cummins Fanatic Join Date: Mar 2008 Location: Louisville, KY Posts: 148 Thanks: 4 Thanked 2 Times in 2 Posts HBKCummins's Truck Pics	i mean i think my starter is on the way out too...but the bottom line is my generator light is coming on and the alternator is not charging up while im driving. __________________ 1996 Ram 2500 5sp. fuel plate, intake, 4in. straight out, golden fuels 160gal. nomad system, 45 hp injectors.

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11-09-2009, 05:25 PM	#14 (permalink)
MX26 Diesel Freak Join Date: Dec 2007 Location: Winnsboro, TX Posts: 585 Thanks: 1 Thanked 4 Times in 4 Posts MX26's Truck Pics	Well, take the charger back and swap it with a different one. Easiest way to eliminate that.. __________________ Trust me.... I'm a doctor. 94 12V NV4500 2wd - #100FF, BHAF, 3GSK, 4" FBD Straight 98 12V Quad Cab Shortbed SLT 4x4 - Auto with a "few" mods

11-09-2009, 08:07 PM	#15 (permalink)
illflem Super Moderator Join Date: Nov 2005 Location: Montana Posts: 6,547 Thanks: 5 Thanked 298 Times in 263 Posts illflem's Truck Pics	There is a temp sensor, usually on the pass side under the battery but on some years it's on the driver's side that must have the bottom of the battery touching it. If the sensor isn't touching the battery and it's below freezing the sensor can tell the computer the battery is frozen and won't let it charge. Since you have oversized batteries it might be something to check. __________________ Bill '95 2500 4wd auto '95 3500 5 speed heavy hauler Not stock

11-09-2009, 08:11 PM	#16 (permalink)
E TEX RAM Cummins Fan Join Date: Jul 2009 Posts: 47 Thanks: 0 Thanked 2 Times in 2 Posts E TEX RAM's Truck Pics	Check the fuse in the power distirbution box. It should be 120A. If that fuse is blown, you won't get a charge at the battery. If the fuse is good, check the output of the alternator. Using a volt meter attach the red lead to the B+ terminal on the rear of the alternator. It is the large terminal with the thick cable. Attach the meter black lead to ground. You should read 13-15 volts if the alternator is charging. If the alternator is not charging, check the field. These are the two small terminals on the back of the alternator. The bottom is positive the top is negative. You should read 3-6 volts normal. Lower than 3 the PCM may be bad or the wiring. More the 6, the PCM VR is trying to get max charging out of the alternator. It means bad alternator. Most often it is the alternator. You can have it bench checked.