I mean what is that for what would I been doing man I am new to all this

---AutoMerged DoublePost---

And also new problem this morning I drove to school parked and went to class came out an hour later got in truck it cranked fine I backed up maybe 25 feet and it shut off??? I tried to crank it again like three times and it would not crank it would turn over but not fire I waited fifteen minutes tried again and it fired up its done this twice now any suggestions

 

Ok
The OPS relay mod is done to take the srain off of the oil pressure switch-when the engine is running the OPS is what activates and powers the diesel lift pump.

The OPS is not built heavy enough to carry that load for long term-the relay mod is done so that the OPS still activates the LP but the relay npow carrys all the load amps instead of the OPS having to.

The stalling is a symptom of a failing PMD but could also be many other tihings.

 

OK so am I just changing wires around or adding a relay

 

Adding 2 relays There is a schematic for the relay mod here : OPS wiring 6.5 TD - Diesel Place : Chevrolet and GMC Diesel Truck Forums

I talked to angelofishes from ebay. He is now selling the Dorman Made in China PMD's. He said he has sold over 100 with the lifetime warrnty and none have come back yet.

You can buy Dorman's from Autozone also. If you need one fast. you will have to come up with something for a heat sink and extension cable if you cannot wait to order

 

2 relays are not required if you follow the diagram I posted earlier.

An additional modification can be added where you wire in parrallel a starter bump button or momentary switch between pins 87 and 30 of the relay and route it to a convienient underhood location so that you can just push it when you need to bleed a new fuel filter.

Also you have to verify that the LP is currently working-if not the relay will not help,lift pumps and OPS's fail.

 

OK thanks guys now can u explain what a heat sink is my pdm looks like a little black box

 

Just get on ebay and type in 6.5 TD in the search and you will see PMD's,heatsinks on the first page.When you move the PMD off the IP you mount the new one to (aluminum block)heat sink to help pull heat from the PMD.

 

That explains so much my pmd does not have a heat sync its in front bumper do I need it since its mounted therw

 

The PMD MUST be fastened to an aluminum heatsink with heat transfer paste/pad between them.

The PMD generates heat when it operates and that heat has to be radiated away from the PMD to prevent it from melting down.

There are many different designs of heatsink,if your PMD is bolted to the bumper with a 5/16" or 3/8" bolt then it does have a heatsink attatched to it-the PMD fasteners that screw it to the IP in the stock location or a heatsink for a remote mount are very small.

 

Um mine is screwed into plastic it was like this when I bought it