Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => Technical / Authenticity => Topic started by: danjarrett1 on January 02, 2018, 11:27:01 PM

Title: 74 Eldorado Reverse light issue
Post by: danjarrett1 on January 02, 2018, 11:27:01 PM
Having a problem with me reverse lights staying on while in drive. I know there is a neutral switch that usually controls the position of the switch so it only energizes the back up lights when it’s in reverse. I understand that the neutral switch is attached to the steering column as opposed to being mounted on or near the transmission. Can anyone tell me how much of a problem it is to adjust or replace the switch? Do I need to remove steering column?
Title: Re: 74 Eldorado Reverse light issue
Post by: The Tassie Devil(le) on January 03, 2018, 12:00:15 AM
The NSS switch is on top of the steering column, in the passenger compartment, just rearward of the firewall, and can be seen by laying on the floor, and looking.

It has the Automatic Park Brake Release coming out of the "back" of it, towards the firewall, where you will see a couple of rubber vacuum hoses, and the opposite side of it, towards the steering wheel, is the wiring plugs, for the Neutral Safety wire, and the reversing light wiring.

These switches can become broken by over use of ones' foot, kicking around under the dash, but rarely can that happen whilst driving normally.

In many cases of the switch breaking, people have been known to put in a jumper wire in the two Purple Wires, so that the engine will crank in any gear, but someone could have put a jumper cable between the Reverse Light plug.

Bruce. >:D

Title: Re: 74 Eldorado Reverse light issue
Post by: danjarrett1 on January 03, 2018, 12:04:55 AM
Sounds reasonable, I’ll look into it!   I don’t think a jumper wire which would allow a start in any gear shift position is wise. Is there any adjustment to it to allow for linkage position relative to the shifter securely in the reverse position?
Title: Re: 74 Eldorado Reverse light issue
Post by: danjarrett1 on January 03, 2018, 12:11:18 AM
I guess what I’m really trying to determine is “what triggers”the lights to come on? Surely it has to do with shifter position or linkage
Title: Re: 74 Eldorado Reverse light issue
Post by: The Tassie Devil(le) on January 03, 2018, 12:13:16 AM
When one adjusts the reversing light switch, one is automatically adjusting the Neutral Start Switch.

If the car will not crank in R, D 2 and 1, but will in P and N, then the NSS is adjusted correctly.

Might pay to try yours and see if it will crank in the gears.   But, be careful.

Bruce. >:D
Title: Re: 74 Eldorado Reverse light issue
Post by: danjarrett1 on January 03, 2018, 12:23:50 AM
That’s a good idea! I suppose the triggering is internal in the switch, it either energizes the back up lights when it’s supposed to or it doesn’t. Thought there might be a way to adjust the switch position to engage the  “energize reverse lights”position on the NSS.
Title: Re: 74 Eldorado Reverse light issue
Post by: The Tassie Devil(le) on January 03, 2018, 12:47:32 AM
No, try to do that, and the switch will break.

When you see the switch, you will understand what I an talking about.

Bruce. >:D
Title: Re: 74 Eldorado Reverse light issue
Post by: 69Deville on January 03, 2018, 02:02:01 AM
Quote from: danjarrett1 on January 03, 2018, 12:23:50 AM
That’s a good idea! I suppose the triggering is internal in the switch, it either energizes the back up lights when it’s supposed to or it doesn’t. Thought there might be a way to adjust the switch position to engage the  “energize reverse lights”position on the NSS.

On my 69, I have loosened the bolt holding the NSS to the steering column and slightly rotated it to get the light to come on. Just barely loosen the bolt enough to turn the NSS. If it's right, the car only starts in P or N and the lights turn on in R.
Title: Re: 74 Eldorado Reverse light issue
Post by: danjarrett1 on January 03, 2018, 08:45:17 AM
Thank you gentlemen! I’ll give it w whirl. The Eldorado is in the shipmfor new top and carpet just now, it’ll be a month before I have it back probably. Will report my findings when I get her home and look into it.
Title: Re: 74 Eldorado Reverse light issue
Post by: 35-709 on January 03, 2018, 10:10:09 AM
While you're waiting to get the car back, do yourself a huge favor and get the shop manual.  The neutral safety switch, its location and adjustment are all in there.  As well as, by the way, the hot water control valve you mentioned in another thread.

As a matter of fact, here is a deal I would jump on for both the shop manual and the Fisher Body Manual, neither of which I would want to be without when working on my car --- or trying to show someone unfamiliar with older Cadillacs what to do.

https://www.ebay.com/itm/1974-CADILLAC-COUPE-SEDAN-DEVILLE-ELDORADO-FLEETWOOD-FACTORY-SERVICE-MANUAL-SHOP/292363749122?hash=item44123cc702:g:EpoAAOSwe09Z7owj&vxp=mtr
Title: Re: 74 Eldorado Reverse light issue
Post by: danjarrett1 on January 03, 2018, 12:27:15 PM
Thank you! I do have the shop manual but could not find specific info on adjustment of the switch or where the vacuum line from the heater valve goes....it might be I one of the schematics provided and I have not check them yet. I just received the fisher body manual yesterday. The body manual is a bit of a disappointment however, it includes , in a very general way, everything from a 1974 Chevy Vega to a Cadillac Eldorado. Are there fisher body manuals specific to the Cadillac in 74?
Title: Re: 74 Eldorado Reverse light issue
Post by: The Tassie Devil(le) on January 03, 2018, 04:56:24 PM
Are there specific Body Manuals for Cadillac?   No.   The Fisher Body Manual covers every body made under the Fisher name for each year.

Bruce. >:D
Title: Re: 74 Eldorado Reverse light issue
Post by: 35-709 on January 03, 2018, 08:59:33 PM
I do not have a '74 manual but I do have a '73.  Using the '73 manual as an example, on page 11 of the INDEX at the back of the manual, under "N", you will see Neutral Switch & Back-Light Switch: and the adjustment procedure on page 12-36 and secondly, the R&I (Removal & Installation) on page 12-38.  You will probably find the R&I page most helpful. 

If the adjustment is correct for the Park and Neutral starting positions (or made to be so), the back-up light "on" position will be correct.  All of this assuming the wiring is hooked up correctly.  There is also a vacuum line to and from the neutral safety switch which releases the emergency brake when you move the gearshift lever out of Park --- assuming you have the emergency brake on of course.   ;D
Title: Re: 74 Eldorado Reverse light issue
Post by: danjarrett1 on January 03, 2018, 09:47:50 PM
I’ll look for that in my 74 manual, thank you for the research. Will also confirm vacuum line secure to the NSS..
Title: Re: 74 Eldorado Reverse light issue
Post by: The Tassie Devil(le) on January 03, 2018, 09:49:26 PM
Did your Auto Park Brake Release work before?

Bruce. >:D
Title: Re: 74 Eldorado Reverse light issue
Post by: danjarrett1 on January 04, 2018, 12:02:11 AM
Honestly, I just purchased this car a few months ago and have yet to deploy the emergency brake. I understand that the vacuum ports on the NSS trigger E brake release....just haven’t confirmed it yet. Unfortunately, the car is in the upholstery shop for the next month getting a new black top and rear glass and carpet.
Title: Re: 74 Eldorado Reverse light issue
Post by: TJ Hopland on January 08, 2018, 09:24:05 AM
The main body of the switch assembly that clamps to the steering column is some sort of cast metal.  The electrical part is plastic and is held to the metal body with a couple little metal tabs that can be really brittle.   If its one of the ones you just can't find replacements for I have been able to find a way to use zip ties to hold them together.       
Title: Re: 74 Eldorado Reverse light issue
Post by: 35-709 on January 08, 2018, 09:38:25 AM
Yes, I've had these apart before.  The tabs that hold them together are pot metal and very easily broken.  Seems to me that Cadillac Tim rebuilds these but not sure.  Cadillac Tim's number is 864-348-3209.