Backup light & Upshift indicator switch - basic info, pinout

[TylerDurden]

I have an 85 MK2 with a 5-speed tranny. The reverse lights would not turn off, so I unplugged the switch until I got another.

I found the correct switch at AutohausAZ: PN 191919823.

The original switch had a pin stuck in the housing.

BrokeVW has a very good page on the subject, with pix.


I made this diagram for future reference. The switches are momentary, normally-open.



The replacement I got also has a problem - It seems the new switch is also prone to sticking, until it is worked quite a bit to loosen it up.  A pain, but electrical bits are not returnable. 

[CRSMP5]

make sure to add in a foglight relay between that and the harness to back up lights.. the bulbs melted the switch... the relay is cheap vs switch...

[8v-of-fury]

Absolutely, I have a 55w spot on my rear bumper as well as the two backup lights. I think if it were the stock setup it'd fry the switch.

Right now my R-lights are a toggle on the dash, which by the way passed an Ontario safety inspection twice.

[TylerDurden]

Good idea.

Even if the bulbs are low draw LED, the wires going to the back can get shorted, like they did in this case. 

[wolf_walker]

Those switches are cheap crap, the current replacements, but better than nothing.  I was able to take apart an original one and repair/reseal it.  One of my dream-020 features is the
early style switch.  I haven't burned one up since I started relaying them though.

[TylerDurden]

Ja, I'm not very impressed with the replacement switch I got.

I have the Rev and 5th buttons working well, but the neutral button is still sticking.

(Not that I care for the upshift light, but I prefer stuff to work the way it's intended to.)

[wolf_walker]

Doing better than me, I've never even seen an up-shift light still working on a diesel.
Not that I'm crying over the lack of, but I like stuff to work if it's present as well.
I take the brackets for the switches off my pumps to make myself feel better.

[fatmobile]

Most of the things I seem to relay are in the engine bay.
 Keeping wires from going through the firewall if they don't have to.
 
 But this wires goes through the cab on it's way to the back so when I finally did relay the reverse lights I used the spot for the fuel pump relay,
 on the fusebox.
 This was with a Rabbit but it had the same wimpy switch.
 The fuel pump relay spot still had all the wires hooked up,
 one fat wire heading toward the back Green/BLack?, even though the diesel doesn't use it.
 I moved it's place in the rear harness 10gray plug,
 the wire that used to go back to the lights now triggers the relay.

[vanbcguy]

Most of the things I seem to relay are in the engine bay.
 Keeping wires from going through the firewall if they don't have to.
 
 But this wires goes through the cab on it's way to the back so when I finally did relay the reverse lights I used the spot for the fuel pump relay,
 on the fusebox.
 This was with a Rabbit but it had the same wimpy switch.
 The fuel pump relay spot still had all the wires hooked up,
 one fat wire heading toward the back Green/BLack?, even though the diesel doesn't use it.
 I moved it's place in the rear harness 10gray plug,
 the wire that used to go back to the lights now triggers the relay.

Sweet idea. I gotta remember that one. My backup light switch is toast too, due to some water getting in to my old cracked tail light.

Never even thought about the fuel pump wiring already being there!

Sent from my HTC One X using Tapatalk 2

[TylerDurden]

Well, the new switch I got is a turkey. 

I believe the internal pins are supposed to get pushed in-between two springy metal tabs, then retract in a self-wiping manner when the cam is no longer depressing the buttons/plungers. The supposedly springy metal tabs are gripping the pins too tightly, keeping the connections closed.   

The pairs of springy tabs are seen in BrokeVW's picture: the lower left pair has marks where the pin pushes in, the lower right pair has heat damage.

http://www.brokevw.com/reverseswitch.html


Looks like I'll have to cut open the new switch and fix it. 

[TylerDurden]

The cover is easy to cut at the seam with a pocketknife.

The switch I got is slightly different from earlier versions:









The root of the problem... sharp edges and burrs on all the contacts prevent them from opening and closing smoothly inside the plastic channels.




I smoothed the edges with my pocketknife and the pins don't seem to get stuck anymore. YMMV.


I imagine the dealer gets $50-$100 for theirs, so I don't think I'll be getting one to dissect & compare.

[92EcoDiesel Jetta]

anyone have a 5 pin connector with a few inches of pig tails  to fit that switch? since swapping to an ACN I have lost my reverse lights because 2 pins went to 5 pins.

[fatmobile]

Most of the things I seem to relay are in the engine bay.
 Keeping wires from going through the firewall if they don't have to.
 
 But this wires goes through the cab on it's way to the back so when I finally did relay the reverse lights I used the spot for the fuel pump relay,
 on the fusebox.
 This was with a Rabbit but it had the same wimpy switch.
 The fuel pump relay spot still had all the wires hooked up,
 one fat wire heading toward the back Green/BLack?, even though the diesel doesn't use it.
 I moved it's place in the rear harness 10gray plug,
 the wire that used to go back to the lights now triggers the relay.

Don't believe everything this guys posts .
 He probably swapped a gasser fusebox into his diesel Rabbit at some point.
 Because my '84 Rabbit with the original wiring doesn't have a spot for a fuel pump relay, ha.
 
 I move the rad fan relay to the radiator shroud, like the Mk2s,.. actually snagged off a MK2 at the salvage yard if I can.
 So that space is open to use.
 With fused power, ground, a long wire heading through the firewall and another to connect to the rear harness.
 The left over fat rad fan wire going through the firewall can be used for a manual rad fan switch.