I just got my wire harness for the 91.5 Cummins and need to identify a couple of things. This is the under hood harness that goes around the engine bay on the fenders. Its for the ECU, firewall connector, head lights, etc.

I have two green/red wires that come out near the ECU harness and have spade connectors on their ends. These wires are aprox 14 gauge and they have no tape or loom on them.

I have a 4 wire flat connector also near the ECU harness. It has a blue weather seal asket and its wire colors are:black, blue/red, green/red, biege/red

The last connector is a five wire funny shaped unit. It is near the drivers side firewall and comes out of the harsness right by grid heater wires. The wire colors on it are: blue (two thicker ones in the same slot), pink, light green, black/grey

If some one could identify what these wire are for and what they plug into that would be a great help. I have included a couple low quality pics to help. Thanks.

 

I think the 5 pin is also left unused on my truck. Dont know bout the others.

 

the 2 green red wires are the horn wires
and the others may be for cruise control

 

I vote cruise, too. Got the same unused plug and no cruise.

 

Any one know about the 4pin connector then? My truck has power inside the cab now but I have no ignition power. I thought maybe I was missing a relay. I have power locks, parklights, headlights, interior light all working but nothing that works off the ignition. So no heater, radio, turn sigals, starter, etc. Any ideas?

 

the 4 pin i would think is the cruise and the 5 pin it looks like a relay goes there but i would look and make sure you have all the wires on the battery and make sure your grounds are good..

 

The funny shaped one that is by itself in the first pic is the computer diagnostic port. For hooking a scanner up to read trouble codes and things like that.

 

Correct. I have a scanner I bought at a yard sale that hooks up there. I use it mostly for setting idle speed, but I have also used it for adjusting the TPS on auto trucks and for looking at the air temp in the manifold.

As was said, the 4 wire plug is for the cruise servo.

The other plugs are for the horns.