# Automotive wiring harness



## rusty (Feb 10, 2011)

When I processed some O2 sensors some of the plugs on the wiring harness had gold plated pins, while some were plated with a silvery metal. I was going to check them for palladium but lost them in the move.

On the weekend found a bunch of fuel pumps that I'll check the connectors from instead.

I'm especially curious which metal has been used on the VDO board, which is for the fuel gauge sending unit.

My preliminary findings, the VDO board is ceramic and the swing arm from the sending unit has two contacts on it.


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## Barren Realms 007 (Feb 10, 2011)

That will be interesting to know.


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## rusty (Feb 10, 2011)

BINGO: The contacts on the sending unit are typically plated with silver-palladium to resist corrosion.

I have not found any information to support that the wiring harness plugs pins have been plated with palladium but it stands to reason they should be.


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## rusty (Feb 10, 2011)

My bet is the VDO board from the fuel pump sending unit is palladium, as the sulfur in the gasoline would react with silver.


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## Barren Realms 007 (Feb 10, 2011)

Could that be most of the plugs on the wireing harness?


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## rusty (Feb 10, 2011)

Barren Realms 007 said:


> Could that be most of the plugs on the wireing harness?



Barren-Reqalms007 some of the on-board computers have gold pins while some are silver looking, it only stands to reason the manufacture has opted to use palladium over gold to save a buck, it would not surprise me that the pins inside the plugs on the harness are plated with palladium.

Like I said earlier, I had a bunch of pins saved for testing but misplaced them last fall, then found a couple of dozen fuel pumps at the dump which tweaked my mind back to palladium.

I'm still a long way from doing any work inside this new shop, perhaps someone with a junker sitting in their backyard could test some pins and report back their findings.

Regards
Gill


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## rusty (Feb 17, 2011)

On board engine computers - various..


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## rusty (Feb 20, 2011)

Pulled all the pins from the on board engine computers, soaking in a dilute nitric acid.


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## Oz (Feb 20, 2011)

I am rather interested in seeing your results on this type of scrap Rusty. I have wondered about it because of hearing about rather high core values for vehicle brain boxes that did not make sense.


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## FrugalEE (Feb 20, 2011)

I don't see gold in any of the photos. Are you trying to recover Palladium.? It seems to me that some connectors that are not gold plated are going to have palladium or something else to take it's place. I found some good discussion on the forum stating you would be lucky to find 1 to 2% of newer boards having Pd and GSP states that Pd alone has a problem in that it draws plastic goo out of the air, so if used needs gold flash or something else over it. I applaud your going to the trouble to test for it. Please keep us informed.

FrugalEE


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## rusty (Feb 20, 2011)

This reaction is only from the pins I removed from the on-board engine computers.

I hate being between moves, some of my chems still at the other house and the driveway is snowed in with a large drift. As such I'm only able to do some preliminary tests.

Overnight the pins dissolved in dilute nitric acid leaving some white salts, some silver foils and some gold behind, washing in hot water had no effect on the salts.

There was no iron in this lot of pins, in my next test I poured the blue solution into some HCL to see if I would get a silver chloride precipitate, nothing showed up but the ratio of acids would now be ar and this turned green immediately.

Later I will add some copper to see if anything will precipitate out as to the silver foils left behind in the nitric we can only assume that it could possibly be platinum the gold foils speak for themselves.

Stannous swab shows brown indicating the presence of palladium.

Dropped in some heavy copper wire, instant black cloud from the green solution. 

Next to test the pins from the actual wiring harness. In a way I'm hoping they're not plated with palladium especially when I think of the many thousands of cars i put through the crusher.

Regards
rusty


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## rusty (Feb 20, 2011)

My next test, this lot of plugs removed from under the dash of a Ford XLT.

Edited February 22/2011, added picture of precipitate collecting on copper pipe.

Looks like it's conclusive that the auto manufacture is plating the male and female ends of the connectors used in the wiring harness.


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## rusty (Feb 20, 2011)

Hidden treasure, the plugs are from the electrical connection at the fuel tank for the electric pump.

The one on the extreme left has been cracked open, if you look closely you will see an ic chip with some gold wires leading off of it. The second picture shows the gold traces better.


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## rusty (Feb 22, 2011)

Double post of the copper pipe used to precipitate the palladium used to plate the electrical pins and connectors used in automotive wiring harness.

The copper pipe clearly shows some of the precipitate from the small batch of plugs I removed from the Ford XLT truck from under the dash.

Makes sense since palladium is much more economical to use than gold or platinum that they would use palladium as a barrier for corrosion.

Your comments are welcome.


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## rusty (Mar 13, 2011)

We've been overlooking a valuable resource here, this would account for the palladium found on the automotive wiring harness connectors.

As soon as the snow is gone I'm going to pay a visit to my local scrap yard with a case of beer, pair of side cutters and a pail to collect all the connectors I can find.

Palladium alloyed with nickel is used as a connector plating in consumer electronics.


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## Malais (Mar 24, 2011)

Very nice post. I appreciate the information.


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## Peter_Griffin (Jun 23, 2011)

Much appreciated. Just started scraping my first car today, I'm sure if I spend the time learning to do the process you have shown it will make my new endeavor much more profitable and interesting.

A little fyi for anyone, probably has been discussed on this board prior, but airbag electrical connectors are gold plated. But remember to be safe, we shot off removed airbags during my auto-mechanics schooling and the force behind it is amazing.

I would love it if anyone could share more information about results from automotive connectors. Like which electrical series of connectors are worth pursuing, and which sensors/relays/switches contained gold or other PMs.

Thanks.


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## Sodbuster (Jun 23, 2011)

PG:
Somewhere here on the forum about a year ago someone posted that the hair fine wire in the Mass Airflow Sensor was a platinum wire. 
I can't say, mite look into it.

Ray


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## ProSmelter (Aug 8, 2011)

:shock: So, did we find out how much Palladium is present in the wiring connectors?? Just curious, dont wanna throw any out till I find out if its worth keepin!!! :shock:


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## tranqmorne (Aug 9, 2011)

I know very little about cars but i have seen on a "how its made" show that in the device that inflates the air bags there is a ball that is gold plated.. i think it acts as a ball valve for air but i could be wrong..


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## davetheman (Aug 9, 2011)

I have been collecting these connectors now instead of just sending them to the crusher. I have a few large boxes full of them and want to start getting the pins removed from the plastic housing.
Has anyone come up with a good method on getting these removed quickly?


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## Barren Realms 007 (Aug 9, 2011)

davetheman said:


> I have been collecting these connectors now instead of just sending them to the crusher. I have a few large boxes full of them and want to start getting the pins removed from the plastic housing.
> Has anyone come up with a good method on getting these removed quickly?



Try soaking them in some hot water and then see if you can pull the connectors out.


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## davetheman (Aug 9, 2011)

I soaked them in boiling water for 15 minutes or so. This made some of the pins pullable but some still did not want to move.

With 50+ Lbs of these connectors i am going to have to find a quicker method.

I think if i some how crush the connectors first then try pulling the pins i will have a much easier time.

Maybe if i put them in some sort of container on the hydrolic press...
I will share results.


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## rusty (Aug 9, 2011)

Some of the more critical connectors are going to be gold plated.

Curious if you tested any of the silvery pins with stannous to back up my claim.

Regards
Rusty


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## davetheman (Aug 9, 2011)

rusty said:


> Some of the more critical connectors are going to be gold plated.
> 
> Curious if you tested any of the silvery pins with stannous to back up my claim.
> 
> ...




I have not tested anything yet. I usually cut all the connectors off of the harness before scrapping anyway, I save the haness without connectors because i get better price for it without all the plastic. When i saw this posting i started saving the connectors instead of tossing them. I just recently found some time to pull some pins and hopefully soon i can try refining a few. I will be sure to share my results. 
By the way my connectors are coming from mostly european cars. Lots of Volkswagen and BMW.


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