simplysmn

OK go to start truck this Morning no charge and no tach and no speedo and no OD even thou OD is on switch then all of a sudden it will start charging and tach will bounce up .Even when it started working I never got OD . Is this CPS or am I looking at PCM? Everything was working Great other day . it did have a hickup the other day as I was getting off freeway it popped out of OD a couple times but went right back in . being that I have a spare PCM I am going to change that first and go from there . But Any Other Idea's ????

gyman98

Sounds like Cps wiring, the cps itself or ground issue. Check battery to frame, battery to engine and battery to body grounds. Also check engine to body and engine to frame

simplysmn

Yeah I think I fixed it my Switch for OD was shorted out some how I went to fire off truck and I saw a Puff of smoke from my switch area . I had a spare PCM and switch and changed both and truck run's fine but I am thinking more of a switch fried that caused it . Thank you Sir for the reply

NJTman

I just went through this.

Turned out to be a fusable link. If you look at this thread, you can see which link it was.

https://www.dieseltruckresource.com/...k-t317257.html

use your test light to see if power is on BOTH sides of the FL. if not, replace the FL and you're done (hopefully)

patdaly

Also check at the connector to the CPS, sometimes they get oil in there and will short out intermittently.

simplysmn

yep Fixed it Atleast so far anyway I changed out the Pot switch on my OD and thing's are back to Normal now .so far so good .
Thank's Guy's for the Help

simplysmn

Hey T truck is acting up and I just checked all fuse link's and everything is good Could it be CPS ? because the Tps is deleted and on a pot switch ? getting ready to do 400 miles on Monday and don't want this to mess up .

j_martin

POT, short for potentiometer, not a switch.

Most likely fault is in the CPS or it's wiring. There are 3 connectors between that and the PCM. One on top front of engine, a 10 pin connector under the intake manifold, and the connector on the PCM. When you messed with the pot, you probably molested the harness going over to the CPS. I'd clean the 3 pin connector on that.

I've found the best cleaner to be a product called DeoxIT. Radio Shack has it in small quantities at a bustard price. Guitar and music centers carry it in more normal measure.

simplysmn

the only thing I did was unplug tps and Plug in the new wiring .Funny thing is it has been flawless up untill I changed core support other day now it want's to bounce in and out of OD .and yes your right it is pot not switch sorry for the mix in typing .I looked in the sticky and it say's something about ASD relay I am going to check that first thing in Morning also along with CPS is there a way to test CPS ? I looked but didn't see anything in sticky thou .

j_martin

The suspect connector is right on top of the engine in front. The wires are in the same harness that feeds the TPS, so you may have moved it a bit. If the connection is intermittent, that could break the circuit. Check and clean that connector.

NJTman

When I swapped out my CPS a week or so back, in order to "test" to see if the one that I put in there last year went bad (which it didn't), I reused my original CPS to the truck. When I put the connectors back together, I realized that the little hoops (whatever they're called) that receive the pin side of the connector had opened up, and the connection wasn't very good. I used the Deoxit that I have a can of, and then after blowing it out with compressed air, I took very small needle nosed pliers and gently closed up those wire hoops in the connector so that when the male end was inserted, there would be a tight fit. You know, kind of like giving it an episiotomy and then fixing it...

simplysmn

Well so far ASD relay fixed it atleast today . I am going to drive some more and see how it goes .

MARF75

You mean like, the extra stitch?