New FSD: No start and short to ground

[AVO]

I have replaced the PMD with a relocation kit.
But it won’t start if the PMD touches chassis/ground.

If I isolate the PMD the vehicle starts right up.

I have tried with both the extension harness and short OEM harness, no difference.

If I try to ground the PMD directly to the negative pole of the battery it shorts and sparks.

Have anyone else had this issue?
Have I gotten a bad PMD?

 

[dbrannon79]

Welcome to the forum @AVO

It's very possible the PMD is faulty. what brand or where did you purchase it from? can you re-connect the old one (make sure it's mounted to the IP or a heatsink) and try it?

 

[dbrannon79]

if the old PMD is no longer functional you can use a multi-meter by connecting the PMD to the harness then key on engine off. use the meter to probe the heatsink and ground. look at the meter and see if you see voltage. then do the same with the old PMD. it sounds like the new PMD is possibly shorted internally

Note: always keep a spare PMD in the glove box. some of us opt to mount a second PMD on a heatkink next to the one in use. use a dummy plug in it to keep the road grime out. when one fails on the road, just pull over and swap the harness with the dummy plug, back on the road in seconds. Optimal remote location is inside the hole on the front bumper with the heatsink fins facing forward to catch wind as you travel down the road.

 

[AVO]

Thanks for the swift replies!

It starts just fine with the old FSD/PMD.
Both before and after the attempted relocate.

I suspect the new box has a manufacturer error.
The new box is made by Dorman

 

[dbrannon79]

Yup sounds like a dud. take it back and get an exchange. for the $$ I would spend the extra and get one from Flight Systems with a lifetime warranty. keep a spare to run and when the new one fails have them replace it no questions asked!

Most auto parts stores question the crap out of you on exchanges especially on electronic items and will only give you a one time replacement for your "limited lifetime warranty"

Oh and don't forget there is a resistor inside the connector on the PMD. I moved mine inside the extension harness connector up by the IP. That way I don't ever have to worry about it again!

 

[dbrannon79]

The resistor is not supplied with new PMD's it's something you have to use a small pick and remove.

 

[AVO]

Unfortunately in Sweden we have a limited availability of parts on stock in country
I’ll see if I can get a refund and order from NA.
Would probably be the best option.

If anyone knows of a dealer who ships to Europe it would be much appreciated!

I have a set of resistors on hand.
So that’s no worries.
But good idea to move it into the original harness

 

[dbrannon79]

Check with Leroy Diesel or Quadstar tuning. they might work something out to ship to you. Leroy is a supporting vendor here on the forum, Chris for @Twisted Steel Performance might also be able to help, he is also a supporting vendor here too. all are good guys.

 

[AVO]

Thanks!
I’ll try to get a refund

 

[MrMarty51]

Thanks!
I’ll try to get a refund

Dorman is warranted for life.
Take it back and exchange it for a new one.
I have a Dorman on My truck and also a Stanadyne.
Both are mounted to their own relocation kits with the unused harness end on stand bye beside the injection pump.
On my Dorman unit, first and second ones I tried, on the highway, cruise control set and the truck engine would give a little hickup and disengage the cruise control, took back that FSD unit and exchanged it for another new one. Three tries and finally got one that works.
By all means, order in a flight systems PMD, but, if it were Me ordering it, i would get it with the relocation kit then You can have the Dorman unit or the flight system on standby at the IP ready to go.
Just also order a PMD harness plug, fill the wire end of it with a good RTV sealant, let it dry thoroughly then plug it into the harness to keep dirt and moisture out og the plug.