1951 Buick Won't Start . . . normally

[longneckgoosie]

So, I've got a 1951 Buick with the 263.

It will start fine if I short across the starter, but won't otherwise. I dismantled and cleaned the accelerator switch, and tested it, it works fine. I'm not really sure where to go next.

I'm guessing it is one of three things:

1. Neutral Switch
2. Starter Relay
3. Wiring (God forbid!)

Where should I look next?

Can I jump across the Neutral Switch to eliminate that as the culprit?
How do I test the starter relay?
Is there something obvious I am missing or forgetting?

Thanks,
v/r
Stephen

['51 Special]

STEPHEN-
I have the same car, but wih a stick shift. So no neutral switch.
I don't see why you couldn't junp the neutral switch to verify that is (or isn't) the problem. If that doesn't identify the problem, I would search for bad connections. (I assume there is no shorted wire in the circuit, or you should have lost a fuse. and that the ignition is working if the car starts when you short accross the starter.) The '52 book on this website has a usable wiring diagram if you lack a manual. ('51s and '52s are identical except for trim superficialities.)
'51 Special

[bob k. mando]

the 1952 Shop Manual should be helpful:
http://www.teambuick.com/reference/l...shop/index.php

[longneckgoosie]

So, I jumped across the neutral safety switch, and it started right up. I guess that tells me what's wrong.

The bad news is I got on ebay and they start around $100!


Does anybody know of a better (cheaper) source for the neutral safety switch for the '51?


Or, has anybody had any success rehabbing one of these switches?


Any help or advice would be greatly appreciated.

[LONG]

make sure it is not just adjustment. may be able to clean up contacts or find a used one.

[longneckgoosie]

<facepalm> Adjustment! Why didn't I think of that? Thanks for pointing out the obvious. I'll just have to go look that procedure up. My beautiful wife has class tonight, so brake switch, and then neutral safety switch adjustment and/or cleaning definitely sounds like a plan.

Thanks,
Gooser

[longneckgoosie]

So I farted around with the beast last night.

I attempted to adjust the neutral safety switch, to no avail. So took it off and threw a multimeter to it. It was showing 1 (no continuity) in any position. I actuated the arm and I realized that it goes all the way around. I tested (with the multimeter) for resistance all the way around the sweep of the arm. I noticed that approximately 180° from where it ought to activate, it would sometimes show a number for resistance (∴ continuity). I then attempted to mount the switch backwards, with the arm in the normal position, but with the body of the switch rotated 180° from the normal position. Unfortunately the mounting flanges are not symmetrical. So back to brainstorming I went.

I remember my father teaching me that sometimes the contacts inside of a switch can be "cleaned" by activating the switch multiple times while power is disconnected from the switch. I figured, why not. The replacement switch is over $100, and this one isn't working now.

So, I rotated the arm 100 times in a clockwise direction, then 100 times in a counterclockwise direction. I figured that oughtta be enough to wear the gook off the contacts inside the switch to a point where it is once again a brass-on-brass connection. (Making assumptions here--the switch is sealed, and I have no idea what it actually looks like inside.)

It worked! I re-mounted the switch in its original position and the old girl fired right up with just a quick couple of tugs on the accelerator linkage.

Awww Yeah. Saved a hundred bucks. :Thumbsup:

Then I started into the brakelight switch project. Couldn't figure out what was wrong with that. Switch tested fine, (though logically backwards, to me, at least,) with a multimeter and the lights seemed to be working fine (tail-lights, etc.) Checked the fuses and the brakelight fuse was out. 14A? What the heck kind of number is 14A? Went to AutoZone, bought a pack of 15A fuses that turned out to be too long for the holders in the fusebox, went back to AutoZone and bought a variety pack of shorter fuses, they're still sitting in the cupholder of my Jeep as it was dark by then and my lovely assistant and I had grown disinterested in further frustration. Hopefully back at it tonight though.

Thank you everybody for the help.

v/r
Gooser