I am replacing the alternator because I think it is draining my battery when the truck is off. What makes me suspect the alternator is the tachometer does not work. Does the alternator have to be designed to operate the alternator or will any alternator operate the tach?
Alternator issues
I ordered a new alternator for my 97 2 door Tahoe and it was different than the one I took out. A previous owner changed the plug and put a 200 amp alternator in. I also have a 94 2door diesel Blazer. The alternator in it matches the new one I bought. Also the alternator in the 94 is on the opposite side of the motor. Is this right? Are the serpentine belts different between a 94 and 97?
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Is the alternator for this truck designed to operate the tach or will any alternator do that?
Thanks Glagulator. The alternator someone put on this truck has a spade connector and a pigtail was spliced on the alternator wires to accommodate it.Your 94 should have a CS130 alternator, has external fan and a rectangular electrical connector, 4 pins with 2 wires.
Your 97 should have a CS130D alternator, has no external fan and an oval electrical connector, 4 pins with 2 wires.
Either truck could have an optional CS144 alternator, uses the same connector as the CS130.
Tach works the same with any of these alternators, I'm not sure about any others.
Thru 95 the tachs are calibrated for a 62mm alt. pulley.
1996-up they need the 57mm pulley, same as the gassers.
Hi Gladiator. There are 4 wires coming out of the harness. 2 go to the alternator. The alternator connector wires were connected to a white wire and a blue wire. The other 2 wires are black and brown.You will need to move the terms like in the drawing.
You do not need a resistor.
View attachment 655177
Hi G, For starters, I like your comment "There are 10 kinds of people in this world; Those who understand binary and those who don't. " Clever. I am bewildered with the truck. It was fleet owned and they clearly had no idea how to work on these. The 2 wire splices here go to the previous alternator. There are 2 white wires. The white wire at the top edge of the screen and brown wire go to a connector not plugged into anything. Any ideas?
The spade connector on the left went to the alternator which I have taken out. I have the right alternator now and the CS 130D pigtail. I just don't trust that the wires the old alternator were spliced to are the right ones. View attachment 656276
The brown wire and the upper white wire coming out of the harness go to the black connector which was just laying on top of the engine.What color are the wires on the black conn. you are holding?
Where do those wires go?
On your 97 there is a harness on the drivers side of the engine that runs
towards the front and has the temp sender conn., a/c compressor conns.,
the EVO conn. on the P/S pump, and the alternator inline connector.
Not the one that plugs into the alternator.
There is a short extension harness that goes from there to the alternator.
The reason was that the old CS144 alternator was an option and it uses the old style connector like the CS130 used. That made it easy to swap between the 2 different connectors.
Here is the short extension the CS130D uses.
View attachment 656277
I cannot believe I found the connector you are talking about. I started pulling on harnesses and it was tucked down under the AC unit not plugged into anything. Brown and white wires. The 4 wire harness in my picture goes back to the firewall and across the firewall to the driver's side and then down behind the fuse box. From there, I am not sure. So I can splice my CS 130D at this connector and my Alternator should work. You are the man.
It was some kind of service vehicle. It has a backup bell and may have had some equipment wired in. That may be why the old alternator was such a high amp one.
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