Haynes manual suggest silicone dielectric grease for ignition module?

Bextreme04 said:

You can have a Thermal paste that is also dielectric(most are, but NOT all).

You can also have a dielectric grease that is not thermally conductive.

The DC-4 is not a good thermal conductor and is a silicone dielectric grease.
The Super Lube Heat Sink compound I linked above is a Silicone dielectric grease that has metal particles blended in to make it a good thermal conductor.

Click to expand...

^ I'm in this camp. As long as it's thermally conductive enough, it should work.

That makes me wonder what the thermal conductivity of the paste they used in the factory was? If the new stuff (thermal paste, dielectric grease, etc.) has the same thermal conductivity value (K measured in W/[m*K]) as it the factory thermal paste, then it shouldn't matter what the name on the tube, bottle, syringe says.

You guys know that thermal paste was not invented till the 2000s and computers got super fancy. Sure there was some other products out back then in the 90s but you had to have some big bucks to spend on a computer So technically speaking the manual is correct for the era of vehicle it was made for.

Dielectric grease was used or any grease really. Now recommended is thermal paste. I've used both. Don't matter usually the part is a POS and fails anyways.

Friend of mine's dad wires aircraft at the local airport with new electronics upgrades. I asked him about the DC-4 and he said they buy it by the case there. Sound like what I'll use to rewire my square.

Bextreme04 said:

Not necessarily. As I said before, they are simply characteristics. They are not mutually exclusive.

You can have a Thermal paste that is also dielectric(most are, but NOT all).

You can also have a dielectric grease that is not thermally conductive.

The DC-4 is not a good thermal conductor and is a silicone dielectric grease.
The Super Lube Heat Sink compound I linked above is a Silicone dielectric grease that has metal particles blended in to make it a good thermal conductor.

They are both silicone based dielectric greases, but only one of them is also a thermal paste.

Click to expand...

sorry about that, I took work experience at work to heart a bit. I'll make sure we don't have any DC-4 if it's got metal in it lol. Don't need someone grabbing the wrong tube by accident.

Working on medical equipment, more specifically, x-ray equipment we are very particular. The heavy duty cables that plug into the x-ray tube require dielectric grease....and there's 3 pins on each connector about 8mm apart. We're talking 60KV on each cable....so we don't like arcing at all lol. Price varies from $4,500 - $140,000 to replace an x-ray tube for a simple error in using the wrong product.

scrap--metal said:

^ I'm in this camp. As long as it's thermally conductive enough, it should work.

That makes me wonder what the thermal conductivity of the paste they used in the factory was? If the new stuff (thermal paste, dielectric grease, etc.) has the same thermal conductivity value (K measured in W/[m*K]) as it the factory thermal paste, then it shouldn't matter what the name on the tube, bottle, syringe says.

Click to expand...

This is a very good point.

Originalthor said:

You guys know that thermal paste was not invented till the 2000s and computers got super fancy. Sure there was some other products out back then in the 90s but you had to have some big bucks to spend on a computer So technically speaking the manual is correct for the era of vehicle it was made for.

Dielectric grease was used or any grease really. Now recommended is thermal paste. I've used both. Don't matter usually the part is a POS and fails anyways.

Click to expand...

I wondered about that, as I had no idea, I just new that pretty much the only place you could get it at was computer / electronics stores.

I think we have our answer right there.

The '78-'83 GM wiper delay modules I've taken apart have had white thermal paste in them, so it must have been around before the 00's.

I've always used dielectric grease and it's never let me down. A lot of modules even come with a little squeeze tube of it. Now with that said, I do agree that a thermal paste would be the proper material to use.

As a side note I always put a dab of the silicon grease on my spark plug wires. It keeps them from sticking to the plugs and or cap terminals.

Originalthor said:

You guys know that thermal paste was not invented till the 2000s and computers got super fancy. Sure there was some other products out back then in the 90s but you had to have some big bucks to spend on a computer So technically speaking the manual is correct for the era of vehicle it was made for.

Dielectric grease was used or any grease really. Now recommended is thermal paste. I've used both. Don't matter usually the part is a POS and fails anyways.

Click to expand...

I’m pretty sure it’s mentioned in the factory manual to use thermal paste. I’m sure the book says to use GM part number whatever, but whatever it’s called it’s a heat transfer paste.

Bosch LH2.4 fuel injection was used on dozens of European cars. One of the major components was a power stage that was bolted to an aluminum base on the inside of the fender with a nice layer of white thermal paste between them. It debuted in 1989.

Hugomartin said:

Would there be a specific ingredient to look for when buying thermal paste heat sink

Click to expand...

Arctic Silver is the best you can get.

True on the white paste but it was not technically thermal paste. Its just a thick silicone/grease white paste that has a higher melting point. And it worked. They needed to put it on the pmd's on the 6.5 turbo diesels lol.


Thermal paste some are still silicone/grease based but has metal oxides in it. The more expensive have fancy better oils, silvers, and what other crap they put in it to make it.

I use artic silver 3 i think it is on my computer projects. For fun I had a old computer and we tried tooth paste even. It worked. To a degree lol.

Truck defnitly seems to run better no stalling at stop lights and downhill . Very tight spot on the truck for that dern inition module. I appreciate the help.

I've experienced the same failures in the past. Always used the thermal paste, but still had failures with store brand modules. I stick with AC Delco because they tend to last longer. I still keep a spare in the glove box.
I found this interesting article:

It is true the conductive grease has a higher thermal conductivity coefficient than dielectric grease, but because the intended gap is so thin (microns), you can almost put anything in there and it will be much better than metal on metal. The best part of the thermal paste and even dielectric grease is they won't flow when hot and wash out. Little microscopic air pockets are the killer in electrical connections like this.

Whichever you use, dielectric grease or thermal paste, the key is to make it ultra thin. A thick layer of goo between the metal surfaces will create a high thermal resistance barrier and you'll cook the module, regardless of which one you use. Also, make sure mounting screws are tight, and definitely not stripped. Clamping pressure is needed to maintain the micro-gap. Just having the surfaces close together is not enough. High contact pressure needs to be maintained.

Hugomartin said:

So the Haynes is wrong?

Click to expand...

Absolutely!

On another note, GM modules were very reliable, but the same is (was?) true for MSD and even Accel. My truck's MSD module was installed sometime around Y2K. But today, who knows where any of them are manufactured, and to what standards? My experience with AC Delco electric/electronic parts has been good, even if most of them are made in Mexican plants. I suspect the AC Delco folks have higher quality standards than modules sold on eBay.

Originalthor said:

You guys know that thermal paste was not invented till the 2000s and computers got super fancy. Sure there was some other products out back then in the 90s but you had to have some big bucks to spend on a computer So technically speaking the manual is correct for the era of vehicle it was made for.

Dielectric grease was used or any grease really. Now recommended is thermal paste. I've used both. Don't matter usually the part is a POS and fails anyways.

Click to expand...

I used thermal thermal paste when I worked as an electronic technician in the 1970s. A common use on a variety of electronic equipment was for mounting a power transistor to a heat sink.

Something like this: