Frustration!

[Neilnaz]

I decided to investigate why the reverse lights on my car do not work.

I removed the bulbs and checked that they were OK - check
Jacked up car and investigated the wiring - pair of wires not connected to the reverse switch - aha progress
Checked whether I could see the reverse light switch - check
Shorted the wires together turned on ignition and put car in reverse - reverse lights on - aha progress
Now to connect wires to reverse switch - very stubby wires sticking out of switch - got one wire out but the other is cut off so snug there is nothing to get hold of

So, having established that if I removed the switch I will lose some of gearbox oil, I will await gearbox oil change time and get the switch out to remove the wire and connect things up.

Blinking frustrating!!!

[timmy2]

Did either of the terminals that are soldered on the end of each wire and insert into the switch come out with one of the wires? You may have more digging to do...
The old original terminals are a poor design with the wire soldered at the tip of the terminal with the wire passing through it first, compared to the newer ones that have a soldering post on the back.
Part number for the new style is 91161290701 @ $6.50 each, you need 2.

[Neilnaz]

Thanks Timmy, the one wire that came out did come out with the terminal. I have no way of getting the other one out unless I have the switch out on the bench and I think I will be able to dig bits out and possibly use a hand drill. I have terminals already attached to the wires awaiting connection. The worst case is that I will need a new switch.

It will get sorted out but just not for little while.

Cheers, Neil

[gamin]

Friend of mine had the same problem. Turned out to be a pin in the trans that wears on the end becoming too short to make proper contact. He made his own replacement pin. I think that there are threads on this subject so search may be your friend.

[Norm01]

You can remove the switch with next to no oil loss. I've had mine out several times to make a pin, you might loose a tea spoon of oil.

[McLaren-TAG]

Originally Posted by Norm01

You can remove the switch with next to no oil loss. I've had mine out several times to make a pin, you might loose a tea spoon of oil.

^^ Agreed. A quarter cup if it's leaning forward on the stands. If the car is tilting slightly rearwards, you'll lose next to nothing.

The rules of general physics apply when working on cars.

[JoeC]

Check the black fuse connector on the left side in the engine bay. Mine was cracked and the pins were not contacting. ordered a new kit 91161211305 and all was good.
Solved some other electrical issues also.

Joe

[Bob Kontak]

Originally Posted by gamin

Friend of mine had the same problem. Turned out to be a pin in the trans that wears on the end becoming too short to make proper contact. He made his own replacement pin. I think that there are threads on this subject so search may be your friend.

Before doing that I would just put the car in reverse and see if there is continuity between the two female sockets in the switch. If so, switch works. If not, pull switch, bench test it and go from there.

I think PP sells an aftermarket that is relatively inexpensive.

Given a wire was off, it's probably just those connectors from hell.

Push pin can be a problem right after a trans rebuild. I don't know if new parts are a little fatter/thinner but the reverse detent/pin thingie cannot reach the "on" engagement. Longer pin required and you make it out of the shank of a drill bit. German drill bit only.

[DRACO A5OG]

Originally Posted by McLaren-TAG

^^ Agreed. A quarter cup if it's leaning forward on the stands. If the car is tilting slightly rearwards, you'll lose next to nothing.

The rules of general physics apply when working on cars.

+2, just did this. I was preparing to lose some oil but none came out.

Thinking is was my broken wire connector like you.

I had to use a needle nose plyer to get my broken connector out and re-soldered it back on and heat shrunk the two. Yes, extremely tight space but possible.

It turned out the switch was bad. OHMs read "OL" when I placed it in reverse. After removal. I verified it was bad, put a DVM on it, stuck a pick tool in the plunger, still "OL" = BAD switch. Just for my knowledge, I decided to lubed the heck out of it, working the plunger and finally got it to read OHMs 000.1 but it was inconsistent as it was on my car.

Post a pic, maybe we can figure it out.

[Neilnaz]

Thanks all for the advice about oil loss or lack of it. I had read one of the threads that mentioned oil loss and concluded removal would result in an Exon Valdez type incident. I will test that the switch actually does short/open before going further (thanks for that Bob).

If it does test OK I will remove the whole switch and dig out the remains of the wire terminal and get it all sorted - hopefully.

Wish me luck!

[Neilnaz]

I bit the bullet and jacked the car up so that I could safely work under it
I removed the reverse switch
The gearbox oil started to come out but I was expecting some loss as per people's comments
Mmmm 2 litres came out - I won't be driving anywhere until that is re-filled. I isn't the end of the world as I don't know when the gearbox oil was refreshed so I will drain the rest and refill.

This was probably because the car was higher at the back than the front by a small amount...

After I had cleared up spillage and got back to it I fished out the terminal that has been stuck in the end of the switch. I have both of them to re-use.



I checked to see whether the metal rod was in place and it was not. So I had to research what size it should be - approx. 60mm seemed to be the consensus. I made a selection:



I then tried each one until I got working reverse lights:



I had to extend the wiring to the switch and used heat-shrink to keep things tidy:



After all that I tidied everything away. Sometimes this car fights me all the way! Obviously the reverse lights have not worked on this car for a long time given wiring nd the rod were missing.

I will research filling the gearbox oil and do that as soon as I can get hold of some Kendal or Swepco.... (I don't want to start a debate!)

Cheers, Neil

[pete3799]

You need to change the location of your trans. ground strap too. It needs to connect to the chassis not the trans. brace that it's going to now.

[DRACO A5OG]

2 Litres? Wait, did you jack up the front or the rear?

+1 re-locate ground strap.

[Neilnaz]

I will relocate the ground strap while I am there - thanks for that.

I jacked up front and rear with all 4 corners on axle stands - I realise in hindsight that jacking up the front would have enabled me to keep all the oil in but I wouldn't easily be able to get under and work on the gearbox (etc.)

Again thanks for your advice.

Cheers, Neil

[DRACO A5OG]

Oh my, well, we live and learn

Good job on making the push pin. That it just awesome!

Take care Brother Neil,

Jim

[Bob Kontak]

Originally Posted by pete3799

You need to change the location of your trans. ground strap too. It needs to connect to the chassis not the trans. brace that it's going to now.

I don't know the older chassis but on my 81 there is a ground lug welded into the body sort of near the reverse switch.

[Bob Kontak]

Originally Posted by Neilnaz

What the eff are these made of?

Is that plumbing solder?

I tol' you drill shank.

That 911 is going to pack a sad.

Hi, I'm Neil. (crowd says "Hi Neil) Here is what I used to use for push pin stock.

[Neilnaz]

That made me laugh Bob - those are not made of Plumbers solder or Swiss Cheese but Steel rod. I think I will make use of a drill bit as you suggest but at least I know the length of the rod required now.

Cheers, Neil

[Neilnaz]

Bob, to make you feel better I have made a replacement rod from a screwdriver shaft (cut down with a dremel) which will be stronger than the installed rod and have put it in the switch - all is working as it should.

I purchased an oil pumping device to assist in re-filling the gearbox and will pick up the gearbox oil tomorrow so the car will be back on the road tomorrow evening - yay!

Cheers, Neil

[cmonref]

In an earlier thread, this was resolved to 59.3mm length of 5/32" drill bit with one end somewhat tapered and rounded. He also used a rubber plug (3/4 x 9/16 x 1") from Lowes to limit the oil loss to 3-4 oz of oil. But if you're gonna change the oil anyway ...

As I recall, the conclusion is that the need for a longer switch actuator was the result of some action during a transmission rebuild.