Backup light / 1-4 issue

[secondchance]

Originally Posted by Paul Workman

Ho! Good ta know. Never thought of that. Neither of our Zs' backup lights work. (Yeah, I know... Raul Julia said it best

https://www.youtube.com/watch?v=wTVDpOaTGsc

Gumball ralley. I think I saw that movie in 1976.
I don?t remember why but developed a habit of leaving my manual cars in reverse just in case parking brake didn?t work right. After back up light switch failure, I changed the habit to 1st gear.

[Matt B]

Thanks for the helpful hints how to remove the switch. I pulled mine today within less then 15 minutes. It's the OEM Pollak switch.
I bench testet it and it works very well. It already engages when only 0.08" depressed (about 2mm) and reads around 0.4 ohm resistance. Resistance is stable through the entire travel of the switch.
When plugged to the harness and manually depressed all backup lamps go up. So clearly there are no electrical issues.

Nevertheless, putting the switch back in place, fully seated and with no additional washer, there is no backup lights in reverse gear...
Looks like an issue with engagement of the switch. I checked the shop manual but there seems to be no adjustment to the engagement pin. Also I could not detect any excessive wear.


By the way - happy easter

[secondchance]

Originally Posted by Matt B

Thanks for the helpful hints how to remove the switch. I pulled mine today within less then 15 minutes. It's the OEM Pollak switch.
I bench testet it and it works very well. It already engages when only 0.08" depressed (about 2mm) and reads around 0.4 ohm resistance. Resistance is stable through the entire travel of the switch.
When plugged to the harness and manually depressed all backup lamps go up. So clearly there are no electrical issues.

Nevertheless, putting the switch back in place, fully seated and with no additional washer, there is no backup lights in reverse gear...
Looks like an issue with engagement of the switch. I checked the shop manual but there seems to be no adjustment to the engagement pin. Also I could not detect any excessive wear.


By the way - happy easter

Send an email to Bill and see what he thinks.
billb@zfdoc.com
http://www.zfdoc.com/S6-40ShifterOptions.htm

[Matt B]

Thanks. I dropped him a message.

Today I checked the activation pin together with my mistress, an endoscope and a hex key. Result: moves nicely in and out even when counter-pressure (as much as was possible with a 1/2 ft long hex...) is applied. So, as long as the switch is properly seated (i.e. its tip touches the activation pin) everything should work. But doesnt... Hope Bill has a hint, I'm running out of ideas.

[ram_g]

Interesting. My OEM switch was haphazard when removed and tested - initially it seemed fine and I was in the same boat as you, but then when I played with it some more it quit working. Wonder if that's the same thing going on with yours.

BTW I sourced my replacement from Eckler's. It looked slightly different but screwed in and worked fine. I'm kicking myself that I didn't take a picture of old and new switches side by side.

[DRM500RUBYZR-1]

I trust you checked the bulbs?
If so; Then.
Replace the switch.

Marty

[Matt B]

I checked absolutely EVERYTHING. Manually engaging the switch (when removed from the transmission housing) turns on all lights as desired. So it's a mechanical issue.

My new Ecklers replacement is already on the way. Hope it will fix the issue. Just takes ages to get it here... And it didn't expect my OEM switch to actually work that fine when bench tested.

[Paul Workman]

[Matt B]

I meanwhile discovered that the switch pin is too far inside the transmission. Fully extended (with reverse gear engaged) it barely touches the backup light pin.

No answer by Bill so far. I will wait for the Ecklers switch but as long as it's not longer and thereby reaches further into the housing it won't help.
In that case I will squeeze a thin teflon disc between pin and switch to fill the gap. I'm sure that's gonna work BUT would prefer the know the reason. There must be a reason and I hope that no tranny internals are affected...

[ram_g]

Originally Posted by Matt B

In that case I will squeeze a thin teflon disc between pin and switch to fill the gap.

Finding it hard to visualize how that disc is going to stay in place, given that the switch contact point is a shiny/slippery ball bearing.