Author Topic: Back-up Light Switch adjustment  (Read 324 times)

Offline Allister

  • Posts: 5
  • Name: Julian GRANDCOLLOT
Back-up Light Switch adjustment
« on: October 02, 2017, 06:49:55 AM »
Hello,

I'm new in this forum. I'm French and I'm a classic cars specialist mechanic. I'm currently working on a 1964 Convertible Cadillac Deville. I need your help (I hope that you will understand my English !!).

The back-up lights switch on when the transmission shift lever position is between P and R, and switch off when the reverse gear is engaged. I removed the back-up light switch. It works perfectly. In the manual that I get, it's written that this switch should be installed with :
# : contact carrier to extreme counterclockwise position (it means extreme left side when you're seated on the driver seat).
# : transmission shift lever in Park.

But when the transmission shift lever is in Park position, the blade on inner shift tube is in the middle of the steering column lining up slot, and not on the left side as it should. So it's not possible to put the blade inside the carrier !! The only way to put the inner shift tube blade inside the back-up switch contact carrier is to move this one approximatively in the middle of the steering column lining up slot...

Anyway, start the car is not a problem, even if it's sometime needed to move the transmission shift lever beyond the Park position.

Does anyone get an idea please ?

Thanks a lot.

Allister

Offline chrisntam

  • Posts: 1279
  • Dallas, Texas
    • CLC Member
      CLC Member #29206
  • Name: C. Jessen
Re: Back-up Light Switch adjustment
« Reply #1 on: October 03, 2017, 06:48:47 AM »
I can't help with your problem, it sounds like you have the factory service manual.  I hope someone with a similar car will assist.

I suggest you update the title to include something like "1964 back up light switch adjustment question",  be sure to include the year model of the car, which may steer more people to your post.
1970 Deville Convertible  MTS 507
Dallas, Texas

Offline russ austin

  • Posts: 588
  • Name: Russ Austin
Re: Back-up Light Switch adjustment
« Reply #2 on: October 03, 2017, 08:28:15 AM »
Just use a volt meter and set it to the continuity check. Hook it up to the NSS on the starter circuit and adjust it till you get a beep on the volt meter.  You should get a beep on Park and Neutral.  Snug up the bolts and retest. Now test the back up lights.
R.Austin

Offline Allister

  • Posts: 5
  • Name: Julian GRANDCOLLOT
Re: Back-up Light Switch adjustment
« Reply #3 on: October 03, 2017, 12:40:53 PM »
Thanks for your replies.

Russ, I know that the Neutral and Back-up Lights switch works perfectly. I have tested it with the voltmeter last week. The problem looks like a wrong alignement between the contact carrier of the switch and the blade inside the inner steering column slot. This blade should be on the extreme left side into the slot when the shift transmission lever is on Park position, but it doesn't. It's in the middle of the slot.

Is it possible to adjust the alignement of this blade ?

Kind regards,

Julian

Offline russ austin

  • Posts: 588
  • Name: Russ Austin
Re: Back-up Light Switch adjustment
« Reply #4 on: October 03, 2017, 03:30:07 PM »
What is the 3 digit number on the back part (metal) of the NSS, and does the car have a tilt steering wheel. I will assume that the transmission is a TH400 as the shift pattern is PRNDDL  You may have the wrong NSS, as there are 4 versions to the 64.

The NSS is adjustable, so with the transmission in R, adjust the NSS so the back up lights come on.  There is no adjustment to the blade, only on the NSS.
R.Austin

Offline bcroe

  • Posts: 2057
    • CLC Member
      CLC Member #14630
Back-up Light Switch adjustment
« Reply #5 on: October 03, 2017, 03:56:34 PM »
For a TH400, the linkage between the steering column and the trans
is adjustable.  Make sure this is positioned correctly first, or it will
throw everything else off.  Bruce Roe

Offline Allister

  • Posts: 5
  • Name: Julian GRANDCOLLOT
Re: Back-up Light Switch adjustment
« Reply #6 on: October 04, 2017, 06:21:45 AM »
Hello Bruce and Russ,

The 3 digit number cast into the top metal part of the NSS is 653.

And to be honest, I don't know if the car has a tilt steering wheel ☺️ but I can check ! What is the way to know the transmission type ? Is there a digit number anywhere as for the NSS ?

I will try to adjust the NSS with the transmission in R and will let you know. I hope that I would be able to start the engine after this adjustment...

Bruce, what the procedure to adjust the linkage between the steering column and the transmission ?

Many thanks.

Julian

Offline russ austin

  • Posts: 588
  • Name: Russ Austin
Re: Back-up Light Switch adjustment
« Reply #7 on: October 04, 2017, 07:23:12 AM »
653 is the NSS for a tilt wheel TH400.   The TH400 has the shift pattern; PRNDDL   A Hydro Matic has the shift pattern; PNDDLR

The tilt column is bigger in diameter, so be sure that the column is a tilt column.
If all is correct, my money is on the adjustment of the NSS.
R.Austin

Offline Allister

  • Posts: 5
  • Name: Julian GRANDCOLLOT
Re: Back-up Light Switch adjustment
« Reply #8 on: October 04, 2017, 11:09:19 AM »
OK Russ. I will try your procedure and will let you know.

For information, my shift pattern is PRNDL...

Thanks again

Offline bcroe

  • Posts: 2057
    • CLC Member
      CLC Member #14630
Back-up Light Switch adjustment
« Reply #9 on: October 05, 2017, 07:55:14 PM »
Quote from: Allister
For information, my shift pattern is PRNDL...   

For a TH400, my basic approach is that when in D, everything in the linkage
should be centered.  The rod coming down to the trans arm should be at a
right angle.  From there check that the selector easily reaches the positions
at the ends.  If one end doesn't easily slip into position, check adjustment. 

One the linkage is good, some of my cars have a switch on the column that
can be adjusted for backup, maybe start as well.  Bruce Roe

Offline Allister

  • Posts: 5
  • Name: Julian GRANDCOLLOT
Re: Back-up Light Switch adjustment
« Reply #10 on: October 18, 2017, 01:25:06 PM »
Hi,

I tried the Russ procedure. The result is not too bad but not perfect.

As you can see on the video attached, there is play in the gear lever, even when the gear is engaged. There is probably the same play inside the NSS.

Any idea about the cause of this play ?

Thanks

Offline russ austin

  • Posts: 588
  • Name: Russ Austin
Re: Back-up Light Switch adjustment
« Reply #11 on: October 18, 2017, 09:59:21 PM »
That's a lot of play in the shift lever. You will need an assistant to look at the linkage at the base of the steering column. Maybe a bad rubber piece, or a loose linkage below.
R.Austin

 

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