I recently replaced the alternator in my '95 C2500 Suburban 6.5L TD 4x4. The wiring harness was cracked so I tried to find a replacement from my local GM dealer. I couldn't find a replacement harness so I ended up buying a universal harness at a parts store. The original harness had two wires coming from the dash; on white, one brown. The new harness has three wires; one red, one brown, one black. I taped the red wire off (to battery?) and hooked the brown to brown and white to black. I noticed that my tach wasn't working. Someone told me one of those wires goes to the tach. I switched them around (brown to black, white to brown) and still no luck. Question....what do the white and brown wires control? Do I need to buy a different wiring harness or could it be that I bought the wrong alternator? Any help would be appreciated.
-
Welcome to The Truck Stop! We see you haven't REGISTERED yet.
Your truck knowledge is missing!
- Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
- We have tons of knowledge here for your diesel truck!
- Post your own topics and reply to existing threads to help others out!
- NO ADS! The site is fully functional and ad free!
Problems registering? Click here to contact us!
Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!
'95 C2500 Suburban 6.5L TD 4x4 - Alternator Wiring
- Thread starter Halex
- Start date
- Staff
- #2
Welcome to the Truck Stop! :thumbsup:
I would get the proper wire connector out of a wrecking yard.
Yes, the alternator on our Diesel's controls the Tach.
I would get the proper wire connector out of a wrecking yard.
Yes, the alternator on our Diesel's controls the Tach.
I hope you checked the pulley diameter. Most parts stores give you a gasser pulley that is smaller than the diesel alternator. An air gun makes quick work of swapping them before the 'core' goes back.
I have been staring at my 1995 all day...
Standing in front and looking at the alternator with the plug plugged in. There are only two wires used. White wire goes to the pin connector/wire closest to the engine (intake) and brown right next to it. The big plug/wire that is closest to the driver's fender is not used. Only use two wires on the plug and cut or tape off the rest - of course only after everything is working. Color of the universal plug is worthless and irreverent. All you care about is position of the wires.
The big wire/pin connector I am talking about is when you pull the plug out and look at it. The fender side will have a big pin connector on one side. The universal may have a thicker wire on that pin.
My 93 has a universal plug and the wires are all white. It works just fine. :thumbsup:
As I recall the wires are battery light on dash that also turns the unit 'on' and the other is the tachometer drive. Other wires may have different 'unused' functions, but, factory 1993 and 1995 only use two wires on the plug.
Some of us upgrade to a CS-144 alternator and make a new rear bracket. The CS130 isn't reliable at all.
I have been staring at my 1995 all day...
Standing in front and looking at the alternator with the plug plugged in. There are only two wires used. White wire goes to the pin connector/wire closest to the engine (intake) and brown right next to it. The big plug/wire that is closest to the driver's fender is not used. Only use two wires on the plug and cut or tape off the rest - of course only after everything is working. Color of the universal plug is worthless and irreverent. All you care about is position of the wires.
The big wire/pin connector I am talking about is when you pull the plug out and look at it. The fender side will have a big pin connector on one side. The universal may have a thicker wire on that pin.
My 93 has a universal plug and the wires are all white. It works just fine. :thumbsup:
As I recall the wires are battery light on dash that also turns the unit 'on' and the other is the tachometer drive. Other wires may have different 'unused' functions, but, factory 1993 and 1995 only use two wires on the plug.
Some of us upgrade to a CS-144 alternator and make a new rear bracket. The CS130 isn't reliable at all.
Hey Halex, welcome to TTS. What part of Houston you in?
Where did you get the Alt from? WW is correct about the wiring. You should have gotten the tach signal from one of the two wires. Since you did not, I asked where you got alt from. Its possible the connection inside alt is not hooked up. Alot of alts have the cappability for a tach output, but they need to be taken to alt/starter place to have the connection made.
Be sure to keep diesel alts pulley like WW said.
Where did you get the Alt from? WW is correct about the wiring. You should have gotten the tach signal from one of the two wires. Since you did not, I asked where you got alt from. Its possible the connection inside alt is not hooked up. Alot of alts have the cappability for a tach output, but they need to be taken to alt/starter place to have the connection made.
Be sure to keep diesel alts pulley like WW said.