Just purchased a 98 3500 4x4 for $3000 with 153000 miles. It had a pump put on at 100000 miles. It had been cuting off or not starting so he got rid of it. With it he gave me an extra PMD part # 34264. The one on the pump and all the ones I see for sale on the cooler kits are 34263. Are there any differences in these 2 pmd-s or are they interchangable. Both have a # 9 resistor.

Well i've never heard of 2 different types of pmd's but it could be just some sort of update. they should both work.

Off the to of my head, 34583 is the latest and is the one that we sell.

34264 is an older model, IIRC, 2nd generation.

I think the difference is only the 34583 have the limp mode while the 34264 will just stall and stop.

Maybe somebody else can confirm it.

at what point in time did the 34583 become stock equipment? or did it? would my 2000 have a limp home pmd or a stall and fail pmd?

If the PMD is good i'd say find a heatsink, weatherproof the entire setup, and mount it behind the front bumper.

Blue, in your case i'd invest in a remote setup for the PMD, since your backup vehicle isn't road worthy right now. I do see you've got the FSD setup, but where is it mounted?

34264 is an older model, IIRC, 2nd generation.

I think the difference is only the 34583 have the limp mode while the 34264 will just stall and stop.

Maybe somebody else can confirm it.

x2. When failing, the 34264 quits same as if you switch off and let you on the side of the road.
The 34583 will still give you some hope to be able to go back home with a good bottle of chilled water :p:

My cooler is located on the intake, as per PO. I do wish to move it ASAP but am too busy currently this weekend, it's a next weekend project for me to try and fix that issue, and also dive into the burb to check what went wrong, and see if i can't make it road worthy enough to be a back up. on the upside for the burb, it started up after 3 crank and glows the other day, smoked and missed and coughed like a son of a gun, but in the end she sounded as good as the day she blew up. i'm so proud of that old burb, and she brought a tear to my ear as she sputtered to life for me :P

need help just replaced my pmd and will not start now


1998 gmc 6.5

If the PMD is good i'd say find a heatsink, weatherproof the entire setup, and mount it behind the front bumper.

Blue, in your case i'd invest in a remote setup for the PMD, since your backup vehicle isn't road worthy right now. I do see you've got the FSD setup, but where is it mounted?

How do you weatherproof it

How do you weatherproof it

You need to use a non-silicone based sealant around the edges of the PMD where it meets the heatsink. You also have to seal the screw holes for mounting the PMD to the heatsink. A bead of sealant on top of each screw hole should suffice.

Jacob ------- Start a new thread

You need to use a non-silicone based sealant around the edges of the PMD where it meets the heatsink. You also have to seal the screw holes for mounting the PMD to the heatsink. A bead of sealant on top of each screw hole should suffice.

In another thread I asked about weatherproofing a PMD, and
I was told to use silicone - now you say non silicone - why?

In another thread I asked about weatherproofing a PMD, and
I was told to use silicone - now you say non silicone - why?


Silicone is acid based. If the sealant smells like vinegar its acid based. I wouldn't use it personally. I found this out after using silicone on my cab lights myself. The stuff really does reek like someone dropped a full bottle of vinegar and it broke.

In another thread I asked about weatherproofing a PMD, and
I was told to use silicone - now you say non silicone - why?

No acid should be around electrical devices. I can't think of any time acid & electronics get along other than batteries & look what happens in them;)

Right now it's a moot point, since the extension harness doesn't work,
but once cured, silicone is inert - prior to curing, it does give off
acetic acid type vapors. But it shouldn't get near the electronic
parts of the PMD, just need to seal the outside where it meets cooler.

I spent 40+ years in electronics and I assure you - We would never use the stuff. The acids will attack solder connections and copper traces. Just the nature of the beast.
It's not like you're dealing with a liquid, but rather fumes - They are really little and can sneak into about anywhere.

I spent 40+ years in electronics

40 years! Wow, so that IS your picture in the avatar,
thought it was just an antique photograph :D

That's Tesla in the avatar - He was much younger than I am now when that pic was taken :)

It was a joke :)

The permatex ultra black sealer is one I would recommend.Works awesome in everyway.

The permatex ultra black sealer is one I would recommend.Works awesome in everyway.
You would get that at auto parts store?