Battery Not Charging
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Cargo Master
Joined: Sep 2006
Posts: 2,120
Likes: 390
From: Evansville, Indiana
Battery Not Charging
I mentioned in a post here last week about my truck suddenly failing to charge. I was advised to check the "Exciter" wire. So, after reading several threads on the subject, I performed a few tests.
My truck has no voltage at the R/G wire. No voltage at B/W wire. 12v at Y/W wire.
I have the original cluster in the truck but it has been in and out a few times lately. It has a voltmeter gauge. Wien the key is turned to the on/run position the battery indicator lamp does not illuminate.
Recently, the left turn indicator lamp failed and was corrected by simply cleaning the lamp socket and circuit board. Could my alternator repair be as simple as fixing that battery indicator lamp?
My truck has no voltage at the R/G wire. No voltage at B/W wire. 12v at Y/W wire.
I have the original cluster in the truck but it has been in and out a few times lately. It has a voltmeter gauge. Wien the key is turned to the on/run position the battery indicator lamp does not illuminate.
Recently, the left turn indicator lamp failed and was corrected by simply cleaning the lamp socket and circuit board. Could my alternator repair be as simple as fixing that battery indicator lamp?
Last edited by diggerrigger; Apr 24, 2026 at 11:42 AM.
Lead Driver
Joined: Sep 2002
Posts: 9,519
Likes: 2,027
From: North Texas
Red/green is what sends 12V to the voltage reg. Start there. Yes, no batt lamp causes issues. No idea if 95MY have a resistor to still charge regardless of the bulb. No real reason to diag further until you have 12V there.
Buy an EVTM for these, best money you can spend to see what goes where and how
Simple repair I am sure.
Hell, need to see if there is a quick disconnect for that wire near the batt. If so, a simple wire with alligator clips on both ends can jump it and shoot power to the alt. If it charges, use a DVOM, then back track to the cluster.
Buy an EVTM for these, best money you can spend to see what goes where and how
Simple repair I am sure.
Hell, need to see if there is a quick disconnect for that wire near the batt. If so, a simple wire with alligator clips on both ends can jump it and shoot power to the alt. If it charges, use a DVOM, then back track to the cluster.
Thread Starter
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Cargo Master
Joined: Sep 2006
Posts: 2,120
Likes: 390
From: Evansville, Indiana
Thanks for the help. I jumped battery voltage to the R/G wire at the alternator and it started charging fine. I'll fix the charging system indicator lamp next.
Notice I changed "battery" indicator lamp to "charging system" indicator lamp. That's what the Owners Manual calls it.
Notice I changed "battery" indicator lamp to "charging system" indicator lamp. That's what the Owners Manual calls it.
Lead Driver
Joined: Sep 2002
Posts: 9,519
Likes: 2,027
From: North Texas
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More Turbo
Joined: Apr 2018
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From: pine city washington
my alternator is week. it puts out the voltage but not the amps? it is the original fgrom 88 so i was thinking if the 120 amp upgrade.
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Lead Driver
Joined: Sep 2002
Posts: 9,519
Likes: 2,027
From: North Texas
You have a 3G now, check the voltage regulator bruahes if so so output. I have received more miles from just slapping brushes on a VR before
Also the 3G should be 95A at least, I think there was also a 130A option in that mounting style. Hopefully someone can confirm for you
Also the 3G should be 95A at least, I think there was also a 130A option in that mounting style. Hopefully someone can confirm for you
Thread Starter
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Cargo Master
Joined: Sep 2006
Posts: 2,120
Likes: 390
From: Evansville, Indiana
Got back to this job today. I pulled the cluster out so I could work at the bench. The charging system indicator lamp showed no continuity. I cleaned up the bulb socket a bit, pulled the bulb (good) out and then plugged back in several times and re-established continuity.
With the bulb out of the cluster, the 513 ohm resistor tests dead (open ). So, I guess no power through the bulb or resistor was/is the problem. Also, the larger red with green wire opposite the green with red wire on the cluster connector is powered with key on. This wire is the ignition feed if Haynes is to be believed.
With the bulb out of the cluster, the 513 ohm resistor tests dead (open ). So, I guess no power through the bulb or resistor was/is the problem. Also, the larger red with green wire opposite the green with red wire on the cluster connector is powered with key on. This wire is the ignition feed if Haynes is to be believed.
Last edited by diggerrigger; Apr 28, 2026 at 12:42 PM.
Thread Starter
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Cargo Master
Joined: Sep 2006
Posts: 2,120
Likes: 390
From: Evansville, Indiana
Note to self (others):
I mentioned I've had this cluster out several times. The two larger connectors always put up a bit of a fight. Today, releasing the connector on the tach side of the cluster, I pulled two copper foils loose from the plastic. Investigating, I noticed both of these type connections are sticky. Sticky as in adhering. Though they looked clean, the cleaning cloth with electric cleaner came out brown. Got the sticky cleaned off and re-affixed the two copper foils back in place with super glue. Polished all with 600 grit paper.
I trimmed a very thin silver off the openings where the lock tabs catch. The connectors are easy in and out now.
I mentioned I've had this cluster out several times. The two larger connectors always put up a bit of a fight. Today, releasing the connector on the tach side of the cluster, I pulled two copper foils loose from the plastic. Investigating, I noticed both of these type connections are sticky. Sticky as in adhering. Though they looked clean, the cleaning cloth with electric cleaner came out brown. Got the sticky cleaned off and re-affixed the two copper foils back in place with super glue. Polished all with 600 grit paper.
I trimmed a very thin silver off the openings where the lock tabs catch. The connectors are easy in and out now.
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