Question about 1988 Oldsmobile Ninety Eight

1 Answer

I have a 1988 olds 98 regency brougham and my backup lights not working I need help with checking the safety neutral switch which wires to check for power and counity

Posted by Ethan Doby on

  • Ethan Doby Nov 15, 2016

    Gm called it a twilight sentinel switch the colors are brown black white and green I took a picture I don't know how to upload it



1 Answer

jack layton

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • Oldsmobile Master
  • 5,308 Answers

This is an old diagram I found, hope the wire colors are correct?The dark blue wire carries voltage to position switch for back up lamps. When in reverse the lite green wire carries voltage to back up lamps and the black wire is ground.
I have a 1988 olds 98 regency brougham and my back - 26350649-grmmnbevmth1gpeu1cszi4fd-4-0.jpg

Posted on Nov 11, 2016

  • 16 more comments 
  • Ethan Doby Nov 12, 2016

    Thank you which wire am I checking for power and which wire do I check for continuity

  • jack layton
    jack layton Nov 12, 2016

    Check the dark blue wire first, key on.

  • Ethan Doby Nov 13, 2016

    The dark blue wire has 12 volts I check it with my test light with the key in the on postion now what do I do next

  • jack layton
    jack layton Nov 13, 2016

    Check the lite green wire for voltage with tranny in reverse. Have a helper sitting in the vehicle with foot on the brake and parking brake set. Remember, safety is your responsibility.

  • Ethan Doby Nov 13, 2016

    that wire don't have power is the car in the on postion if so it has no power

  • jack layton
    jack layton Nov 13, 2016

    Start the vehicle, put tranny in reverse. Remember to use safety precautions I mentioned. If that wire isn't hot, I think the position sensor is faulty.

  • jack layton
    jack layton Nov 13, 2016

    You could even use jumper wire to by pass position switch, on the proper color wires, If the back-up lamps work, the problem is the position switch.

  • Ethan Doby Nov 13, 2016

    Yeah I think your right that wire has no power another thing the black tube that the the wires comes out of there's a vacuum line and when you look up a new switch I don't see it

  • jack layton
    jack layton Nov 13, 2016

    The vac line may go to tranny not position switch? My info on your vehicle year, isn't very good.

  • Ethan Doby Nov 13, 2016

    Oh so do the vacuum line comes out of the black tube

  • jack layton
    jack layton Nov 13, 2016

    w/o being able to look at it, I have no idea. Sorry

  • Ethan Doby Nov 13, 2016

    that's kool I'm look at it real good before I remove the switch. I Have another thing my instrument cluster lights don't come on and the ashtray light

  • Ethan Doby Nov 13, 2016

    I'm really grateful for you helping me

  • Ethan Doby Nov 14, 2016

    That's the thing park lights work but cluster lights don't come on and the ashtray light don't come on

  • jack layton
    jack layton Nov 14, 2016

    I'd have to track wiring off headlamp switch or wiring at instrument cluster. I don't have wire colors or wiring diagrams for that. Sorry

  • Ethan Doby Nov 15, 2016

    This is the dimmer switch let me know if you need more pictures

  • Ethan Doby Nov 21, 2016

    Jack r u still helping me

  • Ethan Doby Nov 23, 2016

    can anybody help me please



Add Your Answer


Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Fuse diagram for delta Oldsmobile 88 royal brougham 1988

I have be unable to locate a diagram for free, however the owners manual is available on eBay, here is the link to the auction site. 1988 ORIGINAL OLDSMOBILE OLDS DELTA 88 98 REGENCY OWNERS MANUAL SERVICE...

Jan 19, 2017 | Oldsmobile Cars & Trucks

1 Answer

Where is the blend door actuator on a 88 olds 98 regency brougham and what does it look like

The system in your car is all vacuum controlled so the first this you need to do is locate the main vacuum source under the hood. It is normally located on the passenger side near the firewall. You may see a plastic ball shaped canister or it could be square. Make sure that device has vacuum going to it from the engine

Sep 03, 2016 | 1988 Oldsmobile Ninety Eight

1 Answer

1971 ford f100 pickup neutral safety switch wiring color code

Ford Neutral Safety Switch; Ford Reverse Light Switch; Backup Light Switch.

The Neutral Safety Switch wires in my 1971 Ford F100 are orange with a blue stripe.
The Reverse, or Backup Light Switch wires are black with a red stripe.

There are two sets of two wires across this combined neutral safety and backup light switch, for a total of 4 wires. Photos are at the end of this post.

The switch for the 1971 Ford F100 pickup truck is the same as in many other years and models. For details, including parts numbers, see the following quote from an expert at Ford Truck Enthusiasts:

The neutral switch also controls the backup lights, and is the same 1967/77.

C7TZ-7A247-A .. Neutral/Backup Switch (Motorcraft SW-600)

There is no separate backup light switch..except on 1967/68 F350's.

Neutral switch location 1967/77:

The plastic half moon shaped neutral safety switch mounts on the outside lower portion of the steering column (NOT on the transmission!).

It's activated by an inverted Y shaped lever that snaps on the shift tube

D0TZ-7B097-B .. Lever, Neutral Switch Actuator = From FTE sponsor DIRECT FORD PARTS: Ford suggested retail price: $18.72 / FTE member net: $13.23.

The switch is also still available from Ford, but the website is down so I can't post the list & net prices. .

1978 is the FIRST year the F100/350's have the neutral switch mounted on the transmission. __________________

Bill // Retired Ford Parts Manager // SoCal Chapter member // Part Number Research: 1928/2001 FoMoCo vehicles.

Driver side of the neutral / reverse switch showing the travel slot for the switch arm, the return tensioning spring, and the arm.

The front, steering wheel side of the neutral / reverse switch after removal from the steering column. The switch's two functions are actuated when the lever in the column moves the switch lever shown here to different positions as gears are selected.

The neutral switch is installed on the steering column near the firewall, with 5/8" bolts into the steering column (visible hole) and down column from a rectangular opening in the column housing. The actuating lever for the switch is attached to the gear shift shaft inside the housing; the lever is visibly protruding from the opening in this image.

Back of neutral / reverse switch, showing the wiring attachments. Black with red stripe is the backup light wiring, Orange with blue stripe is the neutral safety switch, it prevents starting in gears other than neutral & park.

Aug 03, 2010 | Ford F-100 Cars & Trucks

2 Answers

Bronco wont start 88 ford bronco just replaced tranny and now won't start. i've hooked everything back up but one of the wires to the transfer case bc i broke the plug in. any ideas why it wont start...

The neutral safety switch is located on the side of the transmission and it is usually attached behind the shifter linkage and it is secured with two small bolts that can be loosened up to allow for adjustment of the neutral safety switch.

To adjust the neutral safety switch place the transmission into neutral, (block the tires) there is a notch or and indent marker on the housing of the neutral safety switch that should be lined up with a line on the face of the collar that is around the shifter detent shaft, and if they are not in alignment then loosen the two bolts that secure the neutral safety switch and then turn the neutral safety switch until they are aligned and then tighten the securing bolts to the neutral safety switch, and then test the starter. If the starter fails to engage then either the neutral safety switch is faulty, the neutral safety switch has been by-passed all this time and the by-pass (I will usually find things like a paper clip shoved into the vehicles wire connector with electrical tape around it) has fallen out of the wire connector from the vehicle wiring harness, or the battery just went dead. if you have the neutral safety switch from the old transmission still available try using it to test the neutral safety circuit. I have provided you with an image to help assist you adjust the neutral safety switch.


Jun 20, 2010 | 1988 Ford Bronco

2 Answers

Starter has power to it but has some problem from the key to the starter Does this model have a relay or something?

Check the neutral safety switch,if it is o k,then replace the ignition switch,Not the key cylinder,but the electrical part.

Jan 23, 2010 | 1991 Oldsmobile Ninety Eight Regency

2 Answers

Need to locate backup light switch on 1988 chevy 1500

I had the same problem. My backup lights wouldn't come on in when I put the auto. trans. shifter into the Reverse position. They WOULD come on briefly as I moved the shifter from Park position into Reverse, but would go off again when the shifter reached the Reverse detent. I got the solution from the Haynes service manual, in which the relevant switch is referred to as something like the neutral safety switch. Check on top of the steering column close to the firewall. Set the parking brake, then move the auto. trans. shifter into Neutral position. Get under the dash and rotate the neutral safety switch clockwise as far as it will go. Then move the shifter into the Park position, and your switch should be set. If the backup lights don't come on now when the shifter is put into Reverse position with the ignition switch 'on', there may be another problem.

Feb 10, 2009 | 1988 Chevrolet C1500

2 Answers

My Backup (revers) lights dont light up.Fuses & lights not burt.

As far as your back up lights....check the neutral safety switch. This was a BIG problem on the 98-99 Cadillacs.

On the heated'll have to check for voltage at the harness where it connects to the seat(s) if you can do this.

Nov 18, 2008 | 1998 Cadillac Seville

2 Answers

1990 Olds 98 Regency Brougham - Programming Keyless Entry

Same car same problem, but I found the plug w/two wires behind the glove box. It is on a brace on the left hand side, has a clip holding it there. Lift up on the clip and it slides off.
I jumpered those two wires, the door locks did not cycle as was in the instructions and remote still doesn't work.
Sounds to me like I'm missing power from somewhere, but where?
Hope you find your wires and they work for you.

Nov 10, 2008 | 1990 Oldsmobile Regency

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

183 people viewed this question

Ask a Question

Usually answered in minutes!

Top Oldsmobile Experts


Level 3 Expert

85239 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22485 Answers

Jeffrey Turcotte
Jeffrey Turcotte

Level 3 Expert

8984 Answers

Are you an Oldsmobile Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides