Back up lights on 56 Crown Vic

[Woodie UK]

Just noticed the back up lights on my 56 Crown Vic are not working...they may not been working when I first bought the car 12 months ago..never looked until now, Doh!

There doesn't seem to be any power at the switch and I can't find any wiring diagram in the handbook or shop manual. Has anybody ever located an appropriate wiring diagram? Can't find any trace of any fuses!!!

Also, I can't find a replacement sw (in case I need on) listed in any of the normal suppliers catalogs. Anybody got any ideas?
Colin

[miker98038]

Larry’s shows the switch for the manual trans, possibly the auto uses the neutral safety switch. I’m a west coast guy so I use Larry’s but there got to be someone closer to you.

Here’s the link to the pass car catalog.

https://www.larrystbird.com/wp-conte...-passenger.pdf

[fordrodsteven]

I would think that a back up light switch would be common to most all Ford products of the era. Possibly try looking at a Thunderbird switch in one of those supplier catalogs to see if it looks like what you want.

[fordrodsteven]

Mac's Auto parts lists a switch for standard shift transmission and it lists a different switch for automatic transmission.

[5851a]

Not sure on Crown years but I seem to remember something about reverse light power coming through park lamp or headlamp, so they only work when lights are on. May be on earlier cars, or I'm thinking of another make.

[fordrodsteven]

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Originally Posted by 5851a

Not sure on Crown years but I seem to remember something about reverse light power coming through park lamp or headlamp, so they only work when lights are on. May be on earlier cars, or I'm thinking of another make.

I think this is true for all the fords of those years. The thinking was you don't really need the lights to go on unless it was dark enough to have your headlights on. The designers of the time didn't think in terms of letting other people know you were backing up. Their thought was you will need to be able to see when it's dark.

[fordrodsteven]

Also, I just looked at one of the Thunderbird web sites and it shows the (automatic transmission) neutral safety start switch has two wires coming out of it that turn on the back up lights.

[fordrodsteven]

I pulled this from one of the Thunderbird sites:
well, i don't know exactly on a manual tranny, but on a an automatic, it is located with the floor shift assembly--you can get to it under the car, drivers side....it also incorporates the back-up lights switch - so you have 4 wires going to it--the two blue wires are the neutral start function--there is no start in 'PARK'---just neutral - but you can now buy one (for $10 more than a stock replacement) that has been modified internally to start in park or neutral..all the big t-bird venders have them in stock---($110.00 and $120.00)....make sure you have voltage to the switch with the key on....and you have not melted any wires cause they are close to the exhaust pipes.....two white wires are for the back-up lamps AND the switch is ADJUSTABLE---make sure it has not fallen out of adjustment......ed mlynek

[KULTULZ]

See If This Works- https://norwalkkiwanis.org/images/19...agrams-classic

AT or ST?

[Herman Munster]

The neutral safety switch, b7az-7a247-a, that is for 55-57 cars is also listed as a backup light switch.

[paul2748]

Turn the parking lights or the headlights on and then put it into reverse. The backup lights work through the headlight switch and the switch needs to be pulled out.

[KULTULZ]

Here is what tripped me up. The thread is discussing FORD, not BIRD.

One of the maladies of getting old is diminished reading comprehension...

Originally Posted by Woodie UK

Just noticed the back up lights on my 56 Crown Vic are not working...they may not been working when I first bought the car 12 months ago..never looked until now, Doh!

There doesn't seem to be any power at the switch and I can't find any wiring diagram in the handbook or shop manual. Has anybody ever located an appropriate wiring diagram? Can't find any trace of any fuses!!!

Also, I can't find a replacement sw (in case I need on) listed in any of the normal suppliers catalogs. Anybody got any ideas?

Colin

Originally Posted by Herman Munster

The neutral safety switch, b7az-7a247-a, that is for 55-57 cars is also listed as a backup light switch.

Again, thank you for catching this. I just hope it was caught before it caused someone to buy something that won't work...

[Grumpy Rick]

Recently installed a new neutral safety switch on my '55 T-BIRD (Fordomatic). Found it had no factory wiring for back up lights, apparently it was an option. You might check yours.

The lights were installed on the car at some point, but never hooked up. No factory wires in the trunk either. Rewired to make it work.

BTW, I used the modified switch to start in park. Works good.

[Woodie UK]

Some great answers and responses...thanks guys
Checked the backup lights with the parking/headlights on, ign on, car in R (it's an auto)..but still nothing.

There doesn't seem to be any power going in or out of the Neutral Safety sw so going to get a new one +new wires and hope that works.
Thanks again
Colin

[fordrodsteven]

Originally Posted by Woodie UK

There doesn't seem to be any power going in or out of the Neutral Safety sw so going to get a new one +new wires and hope that works.
Thanks again
Colin

If there is no power coming out but there is power going in then I would change the switch.
If there is no power, as you say, "in or out" I would look for a problem from the source of power to the switch. You can also do a quick check to see if the wiring from the switch to the lights is functional by jumping power directly to the wire at the switch. Disconnect the wire that goes to the lights and jump to that. I would make a jumper that utilizes an in-line fuse for the test. You could also use that jumper to connect to the power in side of the switch to verify if the switch works and to check the nadjustment of the switch.

[dmsfrr]

Originally Posted by Woodie UK

...There doesn't seem to be any power going in or out of the Neutral Safety sw ...

Originally Posted by fordrodsteven

... If there is no power, as you say, "in or out" I would look for a problem from the source of power to the switch....

The red/blue wire from the "S" terminal of the Ign key switch should provide power to the neutral safety switch, but only when the ignition switch is held in the Start position.

If the NSS really isn't getting any power the starter solenoid and starter shouldn't function either.

Because the car starts you'd think that's all working fine, except...
if the car can start in gear the NSS is bad, out of adjustment or a previous owner bypassed it with a connection directly from the Ign switch to the starter solenoid. (like a certain red car in my garage)
.

[junkyardjeff]

Back up lights were optional.my 55 never came with with them from the factory and are wired to the light switch and only come on when the lights are on. I am thinking about hooking them up to the accessory side of the ignition switch.

[Herman Munster]

Sounds like you need to get a wiring diagram before you start tossing parts. You then should check the switch for continuity in the Reverse selection with a multi-meter.

[rotorwrench]

Ford was poor about putting good wiring diagrams in their overhaul and shop manuals. What makes it worse is the accessory option factor. The wiring instructions came in the kit and may have not been included in any original wiring diagrams. The diagrams I found for 1956 on line don't show them on the main diagram.

It would be simple enough though. The power may come off the light switch or directly off the main buss circuit breaker then on to the reverse light switch. A single wire likely feeds back with the harness to the trunk where it would split for the two reverse lights. Some diagrams available have the accessory diagrams separate but some don't have them at all

[Herman Munster]

I was thinking about the electrical assembly manual that was released for 1956.