wire nightmare

moneymaker44

moneymaker44

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Joined
Aug 7, 2006
Messages
666
Well it looks like i am going to have to put this thing in the shop.
i have searched every wire and tested until i am out of thoughts here.
this will be the first time in i don't know how long i have put a car in the shop for anything other than Tire's and once for a front end alignment.

Talk about fit to be tied *bdh* but i need my truck rolling again and i can not seem to find the wiring problem myself (i Sux as an eletrician LOL)
 
i was driving along and lost tach ,and no charging. and being an auto of coarse lost OD and lock up. traced wires and really found nothing i did find a few bare wires but nothing so far has fixed it. New ESS or CPS what ever you want to call it. and NEW PCM still no Tach and no charge problem i have bypassed the PCM and hooked a external regualator up but that does not help the trans just helps keep my batteries charged while i test stuff.
 
how about the ground wire for the tach? could be bad ground that was the case for my dads 95
 
Yea I was going to say that looking at any and all associated grounds in and around this area need to be looked at very closely. I have had all kinds of flukey problems with my 69 Scout with the wiring and most of it was related to poor grounds and RUST! Unfortunetly our beloved Dodge Cummins trucks are rotting away as we speak especially where I'm from in the North East!!
 
On the tach and charging issue.

Did you check the clearance between the tack pick up and the balancer?
The pick up can move. If it does you lose the signal.

Take a piece of paper. Fold it into quarters (so it is x4 thick), then slide it between the sensor and the balancer. That is the appropriate gap.
 
i thought i heard somewhere if you are having tach problems and charging problems, it usually the tach sensor. if it reads low rpm, the alternator will not turn on. test the sensor. unbolt it from the bracket and read the voltage with and without a piece of steel in front of the magnet. it should alternate between 0 and 5volts.
 
I use a playing card to set the clearance.
Check the crank sensor wires carefully. I found I had a cracked wire and couldn't tell from the outside of the wire. Soldered in some new wire and all was good.
 
thanks gents but it is a new sensor and been gapped every way under the sun from .050 factory to the old paper trick . i think my problem is a little deeper ! i have the voltage readings at the pcm when it is over the gap on the harmonic and the correct reading when it is on the harmonic . but still do not have a tach reading. gettig coolant sensor input to high ect. i have been tracing wires for days nothing makes the tach move. and no charge . something is shorted but what ? the black with blue tracer connects all the sensors and is the common between all of them but the PCM controls the ground for them ! i was thinking the clock spring could be bad but i can not keep throwing parts into this thing on a guess. so i will have it fixed probably cost me an A** load but when i am done i will post the fix for others .
 
I think it might be time to really get into it with your ohmeter and pay perticuler attention to the areas that are grounds. Do you have a factory service manual? If not I can help you out with the diagrams that you will need to tear into it deaper. Don't give up and go to the stealer just yet one at a time check each wire in the circuit until you get her done. Man I love a good chalange wish ytou were closer. Hmm just went back and read the part about the pcm providing the ground. Hmmm anyone have a spare Pcm to try??
 
man i wish i knew of a spare PCM ! this thing is driving me nuts.
oH it won't be the stealer i take it to there is a guy here in my area who can even flash the comp with updates if needed he is better than the dealer.
the dealers around here are the last ditch resort LOL.
 
did you just buy a PCM and install it? I did the same thing and had the same exact problems. so I put my old one back in. it ended up being another problem. but I heard when you put a new PCM in, that the dealership has to program it or something. maybe give them a call and ask the tech if they do that.
 
Check the main ground wire on the front right of the head. Behind the oil fill.
I know you recently have had the head off.
 
i will recheck that ground joe just to be sure ! but i am pretty sure i sanded it down but i will recheck it anyway. the PCM is not a blank it already has the VIN and miles in it and should work but i am about to send it back to see if it is any good.
 
well it is fixed. it turns out i found all the shorts. but before i stuck it in the shop i decided to send the pcm back to be rechecked . well turns out they sent me a 5.9 gasoline PCM . today the replacement came in and the truck is back up and rolling again
 
Holy Cow thats Nuts! After all that trouble shooting that is what the out come was! I would be happy you found it and pissed that about how it happened. But it's great you finally found it. I always tell my Boy's never give up on troubleshooting somthing mechanical theres always a reason that something is not working right!
 
yes but now it does not want to shift into 4th until about 60mph !
so i gotta look into that
 
Man That suckes! bad thig is I have the same problem! Tach is shuting off and comming back on and its draining my batteries! Has been a hit or miss thig for a while, but last night my batteries got so low the headlights shut off! Now the truck is dead and I had to catch a ride this morning. Hopefuly all these things you guys mentioned can help me figure this out, because 5 techs and a few mechanics cant!
 
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