I 've had some clutch interlock problems getting my truck started,  I wiggle the switch on the clutch pedal shaft and the truck will start.  Today I went to start it, and nothing.  I wiggle the switch and then hop in to start it. No lights on dash, no odometer, Battery has plenty of juice, because I just drove it   I checked the instrument panel fuse, and its fine. 

I know my ECU harness had a few shorts, could that be the cause?

. 

Also, while we are on the topic, can I use an automatic engine wiring harness on a 5 speed truck?

 

I would really like to drive the truck instead of work on it all the time.

 

Appreciate any help folks can offer.

 

Thanks

 

If your clutch switch is causing problems why not fix it? It is a safety feature too. You can try for diagnostic purposes bypassing the clutch switch with a piece of wire and see if it starts. Far as "shorts" in your harness, that would cause fuses to blow or fires to start. Are you sure you don't have connection problems? I am not sure you can use an auto harness in your truck. Just remember, your truck went years without any problems with the harness and clutch switch so I would repair them back to factory or better.

Basically the clutch switch provides the ground or power to the starter solenoid relay. So I would suggest you fix the switch or replace it.

 

I would test all thee fuses under the hood with a ohm meter and verify the fuses all have 0 ohms of resistance. I've seen fuses crack and become a open circuit and not appear blown with the black burn on the window.

Could this be something under the dash?  I was trying to disconnect the clutch switch and then it was dead, no dash, no power, no wts light, etc.

I 've jiggled al of the wires connectors the parking brake, even checked the fuse panel under the hood.  For the dash to go completely dark, and the power windows work, and the headlights work,  is there a particular fuse of connector that would cause there to be no response from the ECM?

You might want to check the big plug just to left of the clutch pedal. There is a 10mm bolt in the center of it but I have seen them loose and have issues

Start with the battery.  Then check your leads.  Then move to the fuse block under the hood, then inside.  Somewhere in that loop, if you look at the factory diagram, you will likely find your issue... Be it fuse, relay, plug, etc.  Use a multimeter to check voltage, or one of the 12V lightbulb style lead testers. 

Edited October 12, 201410 yr by CSM

Ok, I installed a new battery, and that did not help.  I checked the relays under the hood and all ignition related had good continuity, or low resistance.  Also  I noticed the leads to the power distribution box from the alternator had 0 volts.   No power through the 140 A relay, but the headlights work(?).  Hron works, but not the radio.  I jiggled, looked for loose connection under the dash.,  this truck is dead, none of the dash lights work, Could it be the instrument cluster is bad?

 

 I checked the fuses by the parking brake.  the 10A cluster A had 12 volts, but cluster B had 0 volts, and no power to the wipers, radio. I I checked the ignition switch and the resistance was < 1 Ohm on pins 2 ands 7 for start. 

 

I've reached the point where I just want this truck to run so I can sell it.  Thanks for everyone who posted.

Edited October 18, 201410 yr by GSX455

So you have power on one side of the fuse but not the other

140 Amp fuse must be blown if there is no power on the other side. It's only the alternator fuse.

OK, It's the alternator fuse, but why would I have lights, horn, power windows?   What about the instrument cluster?  could that have gone bad, or had a bad connection?  I could remove and clean connections?  Or is it the alternator fuse?

 

Thanks

OK, It's the alternator fuse, but why would I have lights, horn, power windows?   What about the instrument cluster?  could that have gone bad, or had a bad connection?  I could remove and clean connections?  Or is it the alternator fuse?

 

Thanks

 

Because the other stuff are on a different fuse.

 

Instrument cluster you can test.

http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/30-interior/47-instrument-cluster-testing