Changed wire harness now truck wont start

[driver1]

I have a 95 2500 6.5 and the wire harness was a mess, so i got a used one and replaced it. now my truck wont start. all it does is puff black smoke out the exhaust as it turns over. I replaced the glow plug relay and im replacing the turbo boost and the map sensors.. The service throttle soon light is on. any one know what might be the issue????

[trbankii]

First question would be whether the replacement harness was also a 95 2500. Second question would be whether you’re sure you reattached everything exactly.

[Dvldog8793]

Howdy
Verify that the harness was from the exact same year.
I think your year is the transition year from OBD1 so it could be that you got a newer harness and it is causing the problems.
The service throttle soon is due to the "fly-by-wire" foot control in the cab. It is a triple redundancy system. It normally means that you need to replace the foot control...$175 last time I bought one. BUT....with your new harness issue, I would get that verified first before you buy any more sensors or parts. Also verify and correct all your grounds. If you do a search for that on this sight you will get lots of info.

[driver1]

It is also from the same truck. and i do believe we hooked it up correctly.. i didn't have any dash lights come one with the hacked up harness but now i do . the throttle and check light are on. My concern is the engine might be a different year. but every plug is plugged in. I was told there is no tps but then why the throttle light on??

[Robyn]

The TPS is actually there, it's called pedal position sensor (Fly by wire/electronic throttle assembly)

The check engine and the service throttle light will be on until the engine is running.

The plugs on the wire harness are all proprietary and can only plug into one place on the engine, such as the map sensor, crank sensor, optical sensor harness, PMD and so forth.

Does you new harness have the exact same plugs as the old one ??

Does the glow plug relay cycle as it should ???

I have never seen a 6.5 puff black smoke while cranking.

This sounds like a glow system problem and the smoke is probably more gray/white.

Smoke means the engine is getting fuel, so the bottom line is that the glow plugs are not getting hot enough to allow the engine to fire.

Check to make sure you are getting 12v to the glow plugs and that the power is on long enough for the plugs to heat up.

If there is power to the plugs, then you need to yank some plugs and see if they are getting hot.

When working properly a good plug will turn red on the tip and the red will move up the element towards the middle.

Delco 60G plugs are the preferred plugs to use in the 6.5.

The stock plugs that came with your truck were likely tired, and several may have been dead already.

My bet is bad plugs

Good luck

Missy

[driver1]

Right gray white smoke. Ill check them thanks for leading me in the right direction......

[Robyn]

Yup

That means you got fuel, just need a bit of heat to light the fire is all.

Good luck

[phantom309]

i,m thinking you may have injector lines mixed up,..

or pump timing off,.

[Robyn]

Replacing the wiring harness will have nothing to do with the injector lines.

No mention of the lines being removed was ever made.

[sctrailrider]

I might be wrong here as I don't do electronic trucks.. but if everything was unplugged wouldn't the computer need to be relearned from scratch before things knew where they were...