electrical and ignition Accessing big rear defrost wire

[KFunk]

There's a big black/red wire that should control the rear defrost  that I'd like to tap into for fog lights (defroster long dead), and I'd rather not run another wire through the firewall all the way up by the cluster.  I'd like to tap in further downstream for less hassle/hacking.

This black/red wire is pretty heavy gauge.  It leaves the rear defrost switch, and goes into the giant bundle of wires near the steering column, and I can't figure out where it goes from there.  It does not go through the fuse panel (fuse is before the switch).  The two male tabs on the rear defrost have nothing connected to them, so I can't trace it from there.  ]

What route does it take back the rear defrost?  It doesn't go up the A-pillar, and I don't see any going under carpet.

[vinntagejoe]

I've got the same Q, waiting patiently for an answer ?

[harold]

The main wiring bundle to the rear runs along the left side of the car, in clips along the inner rocker panel.  It then runs under the rear seat, up along the wheel well and up through the hole into the trunk.  At the top of the wheel well, right before the harness enters the trunk, a red wire comes off and goes to a bullet connector, then to the black wire for the defroster. 

 

Probably not the answer you were looking for....

 

Harold

[KFunk]

12 minutes ago, harold said:

The main wiring bundle to the rear runs along the left side of the car, in clips along the inner rocker panel.  It then runs under the rear seat, up along the wheel well and up through the hole into the trunk.  At the top of the wheel well, right before the harness enters the trunk, a red wire comes off and goes to a bullet connector, then to the black wire for the defroster. 

 

Probably not the answer you were looking for....

 

Harold

 

All help is good help!

 

So, the defrost wire is solid red at that point, and the normal gauge?  I saw that bundle, but it didn't look like it contained the big black/red wire that I saw at the switch.  It must change at some point.  I'll pull it apart near the firewall soon and test the red wire and see its controlled by the switch.  

Edited April 25, 2016 by KFunk

[harold]

From the 76 wiring diagram:  Green/Blue wire comes from fuse 3 to rear defroster switch.  Red/black goes from switch back to rear connector (in picture).  I guess my picture doesn't show the black stripe.  

 

Harold

[KFunk]

1 hour ago, harold said:

From the 76 wiring diagram:  Green/Blue wire comes from fuse 3 to rear defroster switch.  Red/black goes from switch back to rear connector (in picture).  I guess my picture doesn't show the black stripe.  

 

Harold

 

I don't know, but I don't think that's the same gauge or color pattern as the one at the switch at all.  The one at the switch looks much thicker and is more like half black (not a tiny stripe).  

 

I have no idea why it's changed mid-way somewhere in the path, as I can't find where the red/black wire goes into any junction of any sort.  

 

Hopefully I can figure it out tonight.  I have very limited time I can spend in the garage due to other obligations, so thats why I'm trying to streamline this.  

[harold]

Ok,  I took out my wiring harness from the box it is stored in, and checked it out.  The heavy black/red wire goes directly from the female spade connector at the switch, through the bundle back to the connector (which is also a spade connection) behind the rear seat.    Hope that helps.

 

Harold

[KFunk]

Sweet, thanks for your help.  I'll tear open my bundle and cut it in when I can.

 

[KFunk]

woohoo, fog lights connected and switched on!  Just in time before the wife and baby make it home from a long trip.  

 

I pulled apart bundle that goes under sill, and there was the big black/red wire.  It's more like black with a thick red stripe.  There's a red with black stripe too, but its much smaller gauge.

I snipped it at the sill, then pulled it up thru the bundle near the steering column.  That gave me some slack to poke it through steering column hole, and then connected it to my fused relay.  Lights on now with a big pull switch.  Someday when I have time I'll swap it over to the other real fog light labeled position, but for now it'll just have to say rear defrost.  

[vinntagejoe]

get a photo up KFunk