Well, I'm home after a problem-free 1,000 mile trip. I pulled the connector off the parking brake bracket and loosely supported it to another wire bundle with a couple wire ties. It is completely isolated from parking brake release vibration.

When you guys use dielectric grease on a connector, how much do you use? Is this a situation where less is more?

 

Confirmed that stupid wire harness attached to the parking brake is causing my problems also. I applied and released the brake a few times... wham gauges dead and all dummy lights are on, wrench symbol, engine overtemp, hill descent control fault, service advancetrac.

Truck would not restart.

Applied and released the brake a few more times with the key on and everything cleared up.

Thank you very much to everyone who figured this out!

 

Good to hear you confirmed and resolved the issue. Projectnitemare is the man in my book!

 

I've had my truck back from the dealership for about a week and driven it a couple hundred miles with more than a dozen starts with no problems. I still have my low tire pressure light on but will check into that when I get my next oil change/tire rotation. I also have my connector isolated from my parking brake assembly by use of a couple wire ties. I sure hope that resolves the issue and I begin to restore my shaken confidence in the truck. If the problem resurfaces, I will look into hard wiring across the connector whichever wire is related to the "engine overtemp" condition since I think that is the only one that will actually shut the truck down and cause the non-re-start. I hope ya'll are having the same success with your truck. Bandguy, the mechanic put the dielectric grease on mine, so I can help you there. Cya ya down the road.

 

All good so far. I'm so hopeful I spent a few hours washing, clay baring, polishing and waxing my truck. :-)

I have say don't understand the use of dielectric grease on a connector inside the vehicle which is dry since that grease is an insulator, not a conductor (as I thought).

 

I don't understand that either, I'm thinking you may have fixed the problem by just pulling the connector apart and putting it back together. It could be that it wasn't seated all the way or when you pushed on the wires you may have seated a pin that wasn't all the way in.

Denny

 

Yah the grease makes no sense to me either besides somehow possibly making the connection slightly tighter or less prone to vibration?

 

Might be, Denny. I think it is pretty clear that the vibration from the parking brake was causing a connection issue. Between isolating the connector from the vibration and releasing the parking brake with my foot on the parking brake pedal, I'm hoping it is a problem in the past.

 

Maybe Squisher. I had always thought dielectric Grease was a conductor from the way I've heard people describe filling connectors with it before putting them together.

 

I believe it's just to protect from moisture and contaminants. If it was conductive would it not short things out when applied liberally to multi-circuit connectors?

 

And there is my confusion because one mechanic told me it "improves conductivity".

Thanks.

 

Silicone-based Di-Electric greases are considered to be non-conductive in the low frequency and low-powered connections typically found in automotive applications. They react differently in high-power and/or high frequency electronic applications such as radar and other high-powered communications systems, and do conduct under unique circumstance that aren't encountered in a truck.

Most importantly, it protects the connection against moisture intrusion that could eventually cause corrosion and galling of the contact surfaces and raise the impedance of the connection to the point where the circuit fails.

There are conductive Di-Electric greases available that contain microscopic metal particles. (Similar to anti-seize compounds). These usually are not sold for automotive applications, and should never be used in multi-pin connectors like the subject of this thread.

In regular low voltage multiple-pin circuit connectors, such as automotive applications, flooding with a proper insulating grease of low-viscosity dielectric grease is perfectly acceptable unless the manufacturer recommends against it. The grease should have good stability and not contain metals in any form, and be specifically designed for use as a dielectric grease. This generally is a silicone dielectric grease, although some Teflon based greases are also acceptable.

In a multi-pin connector lubing the connections can make it easier to slide slide on/off e. If you flood the connector hole with the grease it does act to stabilize the connection against vibration to some extent, but the connector itself should be properly strain-reliefed/securely fastened down first as the primary line of protection against vibration.

 

Very informative post RWNJ. Thanks.

 

Hello all and thanks for the good info,
I read through a bunch of threads about problems with the 6.2.

Today mine starting knocking loudly. pulled over and checked oil, nothing...or at least nothing on the dip stick. so at least 2 qts low.
Truck was purchased new in July, currently has 6925 miles. dealer came a picked it up. I guess will know more soon.
I have been checking the computer for oil status. even today it read oil life 100%. Oil has not been changed since I purchased the truck. No signs of oil under the truck or coming from the exhaust. Needless to say, I am extremely disappointed.
dgwelsh

 

Have you checked the oil from the time you bought it.

Denny