1957 wiper motor and radio grounds

[Mark S.]

Motor mount ground straps were also present on very late 56s.

[Richard M.]

Rich,

My two cents on your ground questions:

1. 1957 did not have a ground wire from the valve covers and AFAIK neither did any 1956’s
2. Dash bottom brace ground wire was black
3. From the 1956-7 JRM 27. Courtesy Lights
   Will operate with ignition on or off. A plunger style remote switch in each door hinge pillar
   activates the lights when either door is opened. Also check for operation by turning light switch all the way counterclockwise.
4. Wiper ground wire is black
5. Motor Mount ground straps were only present on radio equipped 1957
6. Ground wire on accelerator rod to rear intake manifold bolt on top of spark plug wire bracket on non FI cars

Gary
....

Thanks Gary,

I'll fix my image of the dash brace wire to Black, not Black/White.

Earlier Dan stated the Black/White went to the valve cover, and that 1956 wiring diagram i posted shows it as "Engine Ground". I think it has to come from there.

If not, where would it attach?

Rich

[Richard M.]

Ok, I found a few threads to help learn about the Blk/Wt ground wire.

Dan D. talks about it below. He tore a harness apart to see how it's connected. The Blk/Wt wire (to the valve cover bolt) gets spliced with several other Black wires in the harness. One of them goes to the dash reinforcement. That one is Black.

https://www.forums.ncrs.org/forum/technical-discussion/97820-1955-to-1962-wiper-motor-ground-wire

This one has a photo from John H. of the Blk/Wt wire heading to the valve cover.

https://www.forums.ncrs.org/forum/technical-discussion/88541-ground-wire-on-1957-rewire

I'll post the photo here too. It's the Blk/Wt wire going in between the tach and speedo cables.
image.png
Rich

[Gary C.]

Rich,

There is NO ground wire to the valve covers.

Gary
....

[Rod K.]

1957 AIM shows 14ga B/W grd wire in schematic Sect 12, Sht 15, tied to horn grd et al ckts, just to left of Generator. Pictorially, Sect 12, Sht 6, ties to main eng harness just above dimmer switch & runs to L VC rear inner screw. Elec Ltd harness provides above.

[Richard M.]

Gary, Unsure of your statement, but I did some more research and I'm now convinced the ground went there.

Rod, thank you. I went back and reviewed the AIM Sec 12 Sheet 6 again. Yes, it certainly shows a wire to the valve cover, albeit it does not identify its color or purpose. Originally I thought that was not it. When tracing it back to the main harness grommet at the firewall, yes, it must be the heavy gauge Black/White wire.
Also notice a "Clip" is specified to be mounted with a screw at the firewall to capture the wire.

Here is my AIM Sec 12 Sheet 6 page with notes. I found some engine bay photos I'll post later.
BlackWhiteGround.jpg

[Gary C.]

best to check with Mike McCagh (14)