It's the simple things

[FOR MUD]

That get you. I've been having a problem with my 05 2500HD going into reduced power mode and throwing throttle body codes. Long story short, after many months of checking wires, connectors, grounds....Replacement of throttle bodies, parts of wire harnesses, control modules, adding more grounds only to have the problem come back after a couple of hundred miles. It got so frustrating at one point I was seriously thinking about running it into a tree and collecting the insurance.
But not being one to give up on things.....I gave up and let it sit.
It sat there and sat there....Every time I saw it it just pissed me off more.
Then one day I saw a thread some place on line about elec problems....And it all came to me.......Dielectric grease!!!!!
It will cut down or stop low voltage current....Now I smeared it on ever one of the connectors on this truck that I messed with thinking I was doing some thing good....Nope just making thing worst.
Clean everyone of them out with elec cleaner and the problem is gone.
I've used this stuff for 20+ years on all kind of connectors with out a problem. But with the wire being so small these days, it doesn't take much to make them lose contact...Especially at the connectors.

So to sum it all up....Dielectric grease = The devil.

 

[nvrenuf]

LOL I hear ya.

Once upon a time I had a holy grail '91 crew cab, while I had it the 4l80e died so I had it professionally rebuilt. Shortly after getting the truck back I started having problems with it sporadically going into some sort of "limp mode" (per trans shop, no codes) where it was shifting oddly and the converter lock up was staying on all the time. Naturally, I took it right back to the shop and to their credit they tried hard to fix it for 2 months - 2 computers, shift solenoids, checking and rechecking the harness, pulled the pan tons of times, etc. Ultimately they gave up and suggested taking it to the dealer and if it was their fault they'd cover the cost. Since the problem was intermittent I didn't go to the dealer right away. While changing the air filter I found an injector wire pinched between the throttle body and air cleaner housing, I think I did it during a tune up. After moving the wire the problem was gone forever.

 

[scpaul]

Mud, I worked with electronics for 33+ years and mostly with wires as small as 28 Ga. and possibly smaller. The small wires that you are talking about most likely carried a signal more so than power. Being that small, they couldn't have carried any amperage to speak of. The signal is readable by voltage (almost always very low) and/or resistance. The small connectors tend to oxidize and cause false or no signals and drive things crazy. Plugging them together and un-plugging them a few times usually cleans them, if you still have problems you may need to put new pins or sockets in the connectors. You should put "Conductive Grease" in the connectors when clean so they can't get any oxygen and oxidize. Conductive grease is not really conductive, it's called that because of what it's used for. I tell you this because if the parts guy doesn't know what you need, he might give you a graphite grease which will simi-conduct some and can cause problems similar to what you had. Usually the grease that you want will be translucent and the graphite that you don't want is usually grey to black. You can check with a meter set to the highest/lowest resistance (which ever way you want to say it) and check a string of grease 1/4" long. If the connector never got warm (70* +/-) from friction, resistance or surrounding temp. you could use petroleum jelly temporarily in a bind.

You could also have a broken wire, usually at a connector, that could be changing resistance or opening the circuit.

Good luck, I don't envy you one bit. I used to hate this type of svc. call because you couldn't be sure weather you fixed it or if it will come back.

Good Night, Paul

P.S. If there's anything else that I might be able to help with, just message or e-mail me.

 

[FOR MUD]

Mud, I worked with electronics for 33+ years and mostly with wires as small as 28 Ga. and possibly smaller. The small wires that you are talking about most likely carried a signal more so than power. Being that small, they couldn't have carried any amperage to speak of. The signal is readable by voltage (almost always very low) and/or resistance. The small connectors tend to oxidize and cause false or no signals and drive things crazy. Plugging them together and un-plugging them a few times usually cleans them, if you still have problems you may need to put new pins or sockets in the connectors. You should put "Conductive Grease" in the connectors when clean so they can't get any oxygen and oxidize. Conductive grease is not really conductive, it's called that because of what it's used for. I tell you this because if the parts guy doesn't know what you need, he might give you a graphite grease which will simi-conduct some and can cause problems similar to what you had. Usually the grease that you want will be translucent and the graphite that you don't want is usually grey to black. You can check with a meter set to the highest/lowest resistance (which ever way you want to say it) and check a string of grease 1/4" long. If the connector never got warm (70* +/-) from friction, resistance or surrounding temp. you could use petroleum jelly temporarily in a bind.

You could also have a broken wire, usually at a connector, that could be changing resistance or opening the circuit.

Good luck, I don't envy you one bit. I used to hate this type of svc. call because you couldn't be sure weather you fixed it or if it will come back.

Good Night, Paul

P.S. If there's anything else that I might be able to help with, just message or e-mail me.

Thanks for the reply. So far ( I know I just doomed myself ) the problem is fixed by me removing the grease. From what I've read most of the time it's the throttle body or connector or one of the wire going to it that causes this problem. I had replaced the body which had a new connector on it and two feet of the wire harness going to it and it had a new connector. I had ohm checked every wire in the system a couple of times, yanked and pulled every wire in the engine bay to the cab hoping for a chafed wire or something lose.
I probable spent two hours looking at wire diagram to see what else is connected to this system.
And in the end, I'm convinced I caused the problem with this grease I put on the TB connector when I checked it the first time.

I should really invest in a weatherpact connector kit.

 

[scpaul]

Hopefully you have got it and that's the end of it. If it should come back, I've got a couple of other tricks that might help find it.

Have a good one, Paul