I have a 1995 3/4 ton 2500 4x4 with the 4L80E transmission. It had lots of mud packed around the transmission and transfer case, so I worked on cleaning that out.

There is one wiring connector, with two wires going into it (one black and one red, I think), that is not connected to anything. The two wires are in about a six inch long black sleeve that comes out of the larger wiring harness. It is hanging down beside the driver's side of the transmission. Nearby there is a 4 wire connector and about a 10 wire connector that are connected to a black plastic thing that fastens to the side of the transmission. In addition, there is wiring that connets to a roundthing that goes into the side of the tranny. Other wires, all connected, run back to the transfer case.

But I can't find where this two wire connector is supposed to hook up. It must have been disconnected for some time, and the transmission and transfer case seem to work OK.

Does anyone out there know this transmission well enough to know what these wires are for? Thanks in advance.

 

it has 2 speed sensors on the drivers side of the tranny...2 wires each...sounds like one of those...

 

Thanks for the reply, Argon. You probably are right that the wires are for a speed sensor.

Is it possible that this unit does not have any speed sensors in the usual locations? At both locations on the drivers side of the tranny where the speed sensors usually would go, there is a thin metal sleeve about one inch long and 3/4 inch across. The sleeves are closed on top and open at the face and bottom. But there doesn't seem to be any place in those sleeves to plug in the wire connector.

Since it is a 4x4, the rear speed sensor may be on the transfer case. But should it not at least have a front speed sensor at the usual spot?

The puzzling thing also is that the transmission seems to work perfectly. That doesn't seem likely if a speed sensor was not hooked up, does it?

Any further ideas or info will be appreciated.

 

I had another look under there and discovered that the location for the front speed sensor does have a spot to plug in the connector. Done! I'm assuming that the rear sensor is at the transfer case, which explains why there is no rear sensor installed on the tranny.

What I still don't understand is why the transmission seemed to work perfectly without the front speed sensor connected. What should the symptoms be if the front sensor is not connected?

 

on that 95..you'd set a code,but not neceassarily a ses lite..

the tranny would go to a default mode...pre-determined shifts