I HAVE RECENTLY BOUGHT A 1991 DODGE D350 DUALLY 2WD DIESEL - I BELIEVE MY CLUTCH INTERLOCK SWITCH IS ACTING UP -
2 QUESTIONS - 1ST WHERE IS THIS SWITCH LOCATED?
2ND IS THERE ANYWHERE ELSE THAN A DEALER TO BUY ONE OF THESE THINGS?
THANKS
RJS1

 

It is on the rod connecting the peddle to the master cylinder. Just take the plug off of the switch, put a jumper wire in the plug and forget about it. Don't depress the clutch when starting, your engine thrust bearing will thank you.

 

It sure will... That bearing depends on oil pressure, and speed to float the parts away from each other with the oil film. Neither of those things is available when you fire the engine with your foot on the clutch pedal. I have developed the habit of swinging the shifter back and forth across the neutral gates before hitting the starter.
cheers,
Douglas

 

Wow you learn something new everyday here lol. I always press the clutch in any stick vehicle cause I figured there were less parts that the starter had to turn that was. But what you guys pointed out makes a lot more sense.

 

Thanks - I don't want to sound dumb however when you say a jumper wire in the plug do you me connect the plug connectors together?
RJS1

 

Yes; bypass the clutch-switch.

You can also go about this a couple different ways.

One is to strip both wires an inch or so, twist them together, and tape/insulate, thus bypassing the switch.

Another is to dis-connect the wires from the clutch-switch, splice longer wires to them, and route these to a secret hidden switch that must be ON before the starter will work.

 

There is an OEM jumper that is usually found in the automatic under dash harness.
It's a green connector with a yellow looped wire.

Mark.

 

I just took a piece of wire ~2" long striped each end stick one end into the one side of the plug and stick the other end into the other plug. Basically what you want to do is connect each wire together on the truck side.

Also yes there are several engines out there that are very common for thrust bearing failure, and the one thing that is common with them all is manual transmissions having a clutch "safety" switch.

 

Thanks - This is my first diesel so a huge learning curve.
RJS1

 

The same reasoning applies to gas-burners as well.

 

What'll that do to the cruise control?

 

I bypassed the "safety" switch as soon as I got the truck. There are a couple of advantages to a stickshift that aren't usually mentioned in the stick-vs-auto discussions:
You can push-start it.
If the engine fails but the starter still works, you can use the starter to move the vehicle a short distance, maybe out of the intersection (or off the railroad track)
I never had to do either of these with my CTD, but I have done both with other vehicles. Of course, you can't do this with the "safety " switch in place.

 

Thanks guys

 

i ran my chutch switch to a old on the floor hi-low beam switch. so when i get in i step on it then start and then step on it again. it works real good

 

BRILLIANT !!!


And nobody would ever suspect.