510 Rear window defroster wiring

[iceman510]

Hey all, I am putting back together a 73 510 that I bought as mostly a shell.  It was a race car for about 15 years, but I am putting it back on the street.  I have the rear defroster glass, and I have fixed the dash and taillight harnesses to put the wires back for the supply side.  Now I am looking for any advice on the ground side of the rear window.

 

Is there a specified location for the ground wire to attach to the body?  None of the manuals or the parts diagrams are that detailed.  I'm sure I can find a spot to work, but looking to do it as close to factory as I can, so if you have a picture or even a description of where it goes in a stock car, please help me out.  I have looked at a lot of build threads, but have not been able to spot this in any photos.

 

Thanks.

[datzenmike]

Possibly there was a ground wire in the harness for the lights, fuel sender and the defogger. Black is usually ground.

[iceman510]

Mike,

 

I don't see one, also, this is on the opposite side of the trunk.  I had the entire harness apart and had to add back the fuel sender and defroster power lines that had been cut out. There is no evidence of any harness going across under the parcel shelf to the left side.

[datzenmike]

Perhaps it just grounds to the body nearby. Didn't know the 510 had that option. Had it on my '76 B-210 but bought in Canada.

[iceman510]

Well...That is what I said in the first sentence of the 2nd paragraph.  I don't see an obvious screw location real near, so hoping someone with a car that has one can identify the stock location.

🤨

[thisismatt]

Does this help at all? Only old pic I could find

[iceman510]

Matt- thanks.  I have seen other pictures of this area, so I do have that figured out.  I put a nice new grommet there, but still need to put the headliner in.  I need to know where the other end of that wire should terminate.  I can't find any body ground location near there.  I did find one screw hole on the support under the left trunk hinge.  Might go there or possibly under the rear parcel shelf area.

[iceman510]

I have received some information from someone on the Realm that identified the defroster ground screw location.  It is in the rear shelf support on the left side under the trunk hinge.  Just have to make the ground wire and route in and I can start on the headliner.

[yenpit]

I think I have the factory rear defrost harness if you still need......??

 

TJ

[iceman510]

Can you text or email me a picture of it?  Pretty please? 😁

[yenpit]

14 hours ago, iceman510 said:

Can you text or email me a picture of it?  Pretty please? 😁

 

A picture of a wiring harness? 🧐  Problem is it is buried in a big box of harnesses, up on a pallet rack.  What are you "looking for"?

[iceman510]

Not really sure, confirmation I guess.  I don't at this point know what harness you could really be referencing.  The positive side is just a wire branching off the chassis/trunk harness (near the fuel filler) up the  C-pillar to the glass.  The other end "should" be just a wire from the glass grounding to the body.  I can easily replicate the ground end, and I have already repaired the branch to the positive end.  So I guess just curious what the "harness" would include, no real need.

 

Thanks.

[yenpit]

15 minutes ago, iceman510 said:

Not really sure, confirmation I guess.  I don't at this point know what harness you could really be referencing.  The positive side is just a wire branching off the chassis/trunk harness (near the fuel filler) up the  C-pillar to the glass.  The other end "should" be just a wire from the glass grounding to the body.  I can easily replicate the ground end, and I have already repaired the branch to the positive end.  So I guess just curious what the "harness" would include, no real need.

 

Thanks.

 

I stripped out a 1973 years ago, the car was out of Bay City, so it was rotted, repaired & rotted again!!  I have the OEM rear defrost "harness" in black vinyl wrapped tape.  Sure, it is likely only two wires, but it is factory correct.  I know I saw it (I label everything) last time I was digging thru that box.  If you have already made one, you should be good!

[iceman510]

Next time you come across it, think of me.  I  would still be curious to see it.  Getting first-hand info on how this is set up from the factory has been difficult.  It doesn't show in most build photos due to the location(s) in the c-pillar and under the rear deck.  Seems the two branches should be separate on opposite sides of the car, unless they are somehow joined together under that rear deck.  Factory manual wiring information is extremely generic.

 

Thanks.