Brake light switch install behind booster on a 68 1600

[Dionk]

Greetings everyone

I’m installing a pedal box, brake booster and pedestal from a later model 2002 on my 1968 1600 (see picture).

can anyone offer some advice on how to wire the brake light switch.
 

I’m looking through my old pictures to see if I can find where the switch was originally located. 

im also contemplating dissecting  the wiring harnesses on my 71 2002 parts car to figure this out.  

[AustrianVespaGuy]

I want to say there's a hole in the rear cross member of the booster bracket that positions the brake light switch directly behind where the pedal bellcrank linkage meets the booster pushrod.  Probably a threaded hole and then a locknut so that the switch position is adjustable.  If it's a later booster bracket than I'd be pretty confident that it should definitely be there and hopefully fairly obvious to spot based on that description, so good luck, looks great so far!

[Dionk]

Thanks - I definitely see the location for mounting the switch on the pedestal. See picture. 
 

I also included a picture of the switch on my parts car. The wires run into that covered bundle that goes into the fire wall.

 

Once I install  the the switch on the pedestal where do I connect the two wires? 
 

this is the part that’s perplexing me.

Edited December 18, 2019 by Dionk
Typo

[02Les]

If your 1600-2 originally had a single remote booster, then the switch was in the end of the master cylinder. The wires for it may be hiding up towards the battery tray.

[Dionk]

My own Mystery solved.

 

I found my owners handbook. Wiring diagrams for both the 1600 and the 2002 are included.

 

GN-RT on the 68 1600 is green and red leaving the brake switch and it goes back to each brake light.

 

SW-GN black and green comes into the switch from the fuse.

 

I did a continuity test to verify. (All good).

 

It seems the difference from the 71 2002 and the 68 1600 that the 68 1600 wires seem to have have multiple connections (jumpers) while the 71 simply has the two wires (one into the switch and one out).

 

i include a picture of the 68 1600 wires which are also bundled with a brown wire (not sure about that one yet).

 

So I’m all set...I think. ?

[Dionk]

4 minutes ago, 02Les said:

a single remote booster

Yes - it did only have a single remote booster...I found them. trying to figure out the one brown wire still though.

[zinz]

Brown is always ground

[Dionk]

45 minutes ago, zinz said:

Brown is always ground

Thanks Ed.

 

Would anyone know why it would be bundled with the brake switch wires with electrical tape. I don't see the BR in the diagram releated to the Brake light switch. Its BR-SW (brown with a black stripe) looking for it now in the diagram.. 

 

Seems it may be the wire from the flasher indicator/parking light/ and washer switch to the delay relay.

Edited December 18, 2019 by Dionk
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[Mike Self]

There are two kinds of brake light switches commonly used:   one is hydraulically activated by the pressure generated inside the braking system, the other is mechanical, generally a normally-on switch.  Look at your original master cylinder to see if it incorporates a threaded, hexagonal metal object with two terminals on it.  If so, that's the original hydraulic brake light switch--and if I'm reading the parts book correctly, that's what is in your car. 

 

Later cars, including the one from which you scavenged the booster and its bracket, have a mechanical switch previously described to you.  If you're retaining the original M/C, simply reconnect the wires to the original switch.  If you're going with a dual M/C, from the bundle of wires you pictured, choose the one that is hot only with the ignition on, and is controlled by the fuse that serves the brake lights.  That wire should go on one terminal of the new mechanical switch, and the brown wire (doublecheck to make sure it's the ground, but it should be as brown wires are "always" grounds on an '02) should go on the other switch terminal.  The switch doesn't care which terminal is + and which is -.  Adjust the switch so the plunger is fully extended when the brake pedal is pressed, tape the others out of the way and you're done.

 

mike

[tahoedon]

My Feb 68 1600 had a fitting between the master cylinder and the remote booster.  Two brake lines entered and exited this fitting.  If there was a pressure difference from the tandem master cylinder a piece inside would slide to one side and push a plunger to light the brake warning light on the     gauge cluster.  There was also a hydraulic brake switch on each side of this fitting to light up the brake lights.  Attached is a drawing of this and the wiring diagram for a US 1600.

[Dionk]

2 hours ago, mike said:

one is hydraulically activated by the pressure generated inside the braking system, the other is mechanical, generally a normally-on switch.  Look at your original master cylinder to see if it incorporates a threaded, hexagonal metal object with two terminals on it.  If so, that's the original hydraulic brake light switch--and if I'm reading the parts book correctly, that's what is in your car. 

See picture - I think this is where the wires were connected. This junction has been removed. 

[Mike Self]

4 hours ago, Dionk said:

See picture - I think this is where the wires were connected. This junction has been removed

I think the two switches in your picture are in fact the two brake light switches described in Don's posting immediately above yours.  Easy way to tell--connect a voltmeter across the two terminals and step on the brakes.  If the voltmeter registers, there are the wires you need for the new installation.  Pick one set, and tape up/insulate the other.

 

mike 

[RoccoGilroy]

Im cleaning up the wiring in my early 68 1600 and I too am stumped on the Brown/Black wire that is bundled with the Green/Red and Green/Black… I snipped off the little piggy back on the Green/Red and Green/Black as it’s never going back to the original braking system. I plugged them in and the brake switch works properly so I’ve been happy with it but I I’m still puzzled about the brown and black wire. I’d hate to tape it up and find out later that it’s important for something. Can’t imagine what… Only Brown/Black wires I see on the diagram are the door buzzers and door dome light switches. 🤷‍♂️ 

[jimk]

The only Br/Blk wire I can locate on the wiring diagram is for the windshield washer pump.  From the pump it traces back to the fuse.

[RoccoGilroy]

Ok for any of you out there keeping score. Or for any of you poor bastards out there like me with an early 1600…

 

I couldn’t leave well enough alone so I traced the Brown/Black wire all the way to it’s origin. It originates in the #5 position of the 12 pole plug that connects to the instrument cluster. When I look at my wiring diagram the #5 pin on the plug leads to an unknown and on my diagram unlabeled spot. And it says it’s Brown/Blue… 

 

Maybe my manual doesn’t have the true 68 1600 diagram and it’s for the later 1600’s with the later style brake system. These remote servo cars are weird… 

 

Can someone tell me what the stuff circled in red is on the diagram? That’s where the #5 pin traces to from what I can tell.