1955 to 1962 Wiper Motor Ground Wire

[Richard M.]

I'm having issues with the reproduction Wiper Ground wires from LL and M&H. They supply a wire which is 14 3/4" long, and is too short to reach safely between the wiper motor mount screw and the right inner rear valve cover screw.

The GM part# is 3733145. It is also used for the '55-'57, however those attach to the cowl brace screw, IMO closer to the motor.

Is there a wire length spec for the 3733145 in anyone's possession? I found no help in my '29-'59 P&A Catalog.

Does anyone else have problems with these reproduction wire lengths? On the '58-'62's it seems it needs to be a few inches longer to keep clear of the hot ballast resistor and far enough under the ignition shielding on radio equipped cars.

Rich

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[Joe E.]

Re: 1955 to 1962 Wiper Motor Ground Wire

The wiper ground wire goes to the left inside valve cover rear screw.

[Mike E.]

Re: 1955 to 1962 Wiper Motor Ground Wire

Joe is right on!

[Richard M.]

Re: 1955 to 1962 Wiper Motor Ground Wire

Huh ??????? On a 58-62 it's the right VC. And the 57 AIm shows it to the cowl brace. What am I missing here?

I was kinda just lookin' for the wire length.

[Richard M.]

Re: 1955 to 1962 Wiper Motor Ground Wire

On 1958-1962, the radio ground wire also attaches to the right(pass side) VC along with the wiper ground wire. The main ground from the harness, Black/White-Tracer, goes on the left rear inner VC screw. Maybe that's the confusion?

The picture in the 1957 AIM Section 12 Sheet 6 shows clearly that the wiper ground mounts on the left(driver side) wiper mount screw and attaches to the cowl vent brace stud. I believe the inside gets it's ground from the main harness and connects to the brace internally. I've never torn a '56-'57 apart so I'm not sure, just reading my AIM.

The picture in my 1959 or 1961 or 1962 AIMs Section B Sheet 10 shows that the wiper ground mounts on the right(driver side) wiper mount plate arm screw and goes to the right(pass side) valve cover inner rear mount screw. The picture in the AIMs is shadowed witha carburetor and it's misleading. It looks like the left VC, but it is not, it's the right VC. pics below

So I believe I understand where it goes on the various years,

I'm looking for the wire length if anyone has a spec or their original still available to measure.

Thanks.....Rich

1961 Sec B Sh 10
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1957 Sec 12 Sh 6
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1957 Sec B Sh 7
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[Dan D.]

Re: 1955 to 1962 Wiper Motor Ground Wire

RE: I believe the inside gets it's ground from the main harness and connects to the brace internally. I've never torn a '56-'57 apart so I'm not sure, just reading my AIM.

Rich, I have dissected an old 57 harness, just to figure out just how the grounds are configured. In this case, it is amazing that it works at all. But here is how they did it:

The ground wire goes from the wiper motor mounting bracket to the cowl vent screw, just as you say and the AIM shows it as well. So wiper ground current passes through the cowl vent brace the lower dash reinforcement, where it is mixed with all the dash grounds. Underneath the light switch a harness ground wire attaches to the dash reinforcement plate. This wire then disappears into the harness. Inside the harness a crimp style butt connector connects 6 or more ground wires together. The splice is wrapped with the old friction tape to prevent chafing (this much they did right) and then over wrapped with the harness tape. There are several other splices in the harness where common wires are connected together (dash lights for instance). One of the ground wires of course is the left side rocker box ground. This wire and the tail light ground on the rear cross member are the only 2 places that I can find where the frame and engine are grounded. Battery ground has to be to the engine as that is where the battery cable is connected.

So the rocker box ground is it. The problem with it is cover gaskets compress, oil, grease, dirt all accumulate, and the screw can loosen. With steel covers you can add rust to the mix. All this makes for a real poor ground, but somehow it all works.

I was not aware that 58s and up used a right side ground, as 57 is the only year I am familiar with.

Just passing this around in case you are interested.

-Dan-

[Mike E.]

Re: 1955 to 1962 Wiper Motor Ground Wire

Rich,
You're correct--I was thinking of the radio ground wire that comes from the side of the radio to the left valve cover. I just looked at both of my 62 bow tie cars-they go to the right valve cover. They route right over the top of the ballast resistor. My best measurement is that they are slightly over "14. Neither is a reproduction. Hope that helps.
Mike

[Joe E.]

Re: 1955 to 1962 Wiper Motor Ground Wire

I looked at my 58 and it also has a ground to the right side cover, there are 2 black ground wires on the right side and 1 black wire on the left valve cover. The wire for the wiper is 18 in long and it goes up around the ballast resistor. This wire would be a reproduction from the mid 80`s. I have been working on a 56 lately and it is to the left side. Hope this will be of some help.Joe

[Richard M.]

Re: 1955 to 1962 Wiper Motor Ground Wire

Guys, This is all great info. Thanks.

Mike, I figured you knew that and must've been a hiccup about which VC. So.....wow, it's 14", just like the repro's made today. I usually make my own wiper ground wire, but this time I wanted to buy the "right one". I didn't ever realize it was designed that short. Hmmmm.

So I ran the 14+" repro across from the wiper ground mount screw to the right valve cover screw. It was so tight, and like you said, the only way to get it to fit is to run it directly over the ballast resistor! It's scarey there. I can picture the ballast getting hot and melting the wire, then the bare wire vibrates over the exposed hot leads of the ballast. Ouch. I don't like that.

Joe, okay, yes the 56-57 is on the left and now it's clear you were thinkin' of that one. The 58-62 has the 2 grounds(wiper/radio) on the right VC and the main harness ground on the left VC. Your 18" length makes more sense and was probably made longer then due to the IMO the "wrong" original length. Wrong but "correct" I guess. FYI, the 58-62 repro(and maybe the original) Radio Ground wire is actually, IMO, a bit too long. I've used the repros before and I have to tuck the slack inside the firewall area.

Dan, Yours is great info for me because I'm likley going to be restoring a '57 soon. I'll keep your info close by. Much appreciated and thanks for the detailed explanation.

Rich