M1008 Clutch Safety Start Switch Help

[AFC1]

Hey Guys- I am in the middle of restoring/modifying my 1986 M1008. I have removed the TH400/NP208 and am about to install a SM465/NP205 combo. I have finished installing the hydraulic pedals, slave, master cylinder, flywheel, bellhousing, etc. and have a quick question. Anybody ever do this swap and wire up a clutch safety switch? Does anyone have a M1008a1 or A2, A3 that originally came with the SM465? There is no neutral safety switch existing because of the gated automatic steering column. My truck's electrical system is mint and completely untouched and I really do not want to start hacking it all up, but on the other hand- I would be devastated if anything ever happened to my 2 1/2 year old daughter if this thing started in gear. Unfortunately, I am not the only driver. Any info or help would be greatly appreciated....thanks for your time.

 

[Warthog]

I have a 1990 Chevy Suburban with a stock SM465. The clutch switch is nice.

I'll see if I have some diagrams from the Burb.

The 1983 CUCVs had a neutral safety switch. The 1984 thru 1986 did not.

Here are the diagrams that show the switch and non-switch



You can tap into the yellow wire coming off the ignition switch which feeds the starter relay when the key is in the START position

 

[AFC1]

I have a 1990 Chevy Suburban with a stock SM465. The clutch switch is nice.

I believe you could use the wires from the neutral safety switch. Remove the wires from the neutral switch and "insert" a harness for the clutch switch. No wire cutting involved. Going off memory, the automatics used the shift position to close the circuit for the starter. Park and Neutral. It should work for the clutch being depressed.

I'll see if I have some diagrams from the Burb.

I had previously looked under the dash when I had my steering column down and I didn't see any neutral safety switch. I was told that there really was no neutral safety switch as found on the older model trucks, these steering columns were gated and that is how they would only start in park and neutral. I had neutral safety switches on my 83, 84, 75 trucks, but can't find one on my CUCV. I have a brand new GM clutch safety switch and compared the wiring to a civilian truck of the same year, and the wiring is different. I see the heavy purple wire on the CUCV, but no heavy yellow wire as found on the civilian truck. Also, it appears that the heavy purple wire on my M1008 is coming out of the harness which goes to the glow plugs- do not want to screw anything up. Let me know if you can find your diagrams. I really appreciate it.

 

[llong66]

Hello all, I know this is an old thread and I am researching the idea of a NV4500 swap. Since I am at just the research point, I was wondering, if the clutch pedal has a NSS on it, could you not just run a line, perhaps via a real to one of the wires on the starter relay, the one in the Doghead mod?

Thanks,
Greg

 

[Recovry4x4]

Depending on what year pedals you use, there is a place for a neutral safety switch. Wiring it through the doghead relay would be easy and effective.

 

[Skinny]

Even if you pedal assembly doesn't have it, you could drill it out and install a normally open or closed depending on where you put it momentary contact switch somewhere on the linkage or near the pedal arm itself. Just run the ground from the starter relay (no where on my relay does it say doghead) through the safety switch, then to ground. You could also run it to a sneaky Pete toggle switch as a make shift anti-theft device as long as the criminals can't bumpstart it.

 

[Warthog]

I updated the wiring diagrams for the 1983 and the later trucks. I had some incorrect info in the older thread.

You just need to put a switch in the yellow wire coming off the ignition switch. It supplies power to the starter relay when the key is in the START position