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> 19mm Master Cylinder ground wire, oops
flipb
post Apr 15 2010, 07:29 PM
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My '74 has a 19mm Master Cylinder.

The dash warning light has been flashing incessantly - I disconnected it a while ago. Tonight I was busy breaking my horn mechanism in the steering wheel (IMG:style_emoticons/default/blink.gif) and I decided to try to reset the button on the MC to stop the flashing.

Here's the deal. With the car on the ground and a flashlight, I managed to find the reset button. Hit it, reconnected the warning light on the dash, and it now functions correctly. (stops when the parking brake is released)

However while I was reaching in there, I accidentally disconnected what looks like a Ground wire. I don't think I have any hope of finding where it connects without taking the car to a shop and getting it up on a lift, so...

What is the risk of driving it with the ground wire disconnected from the MC?

I don't think I've ever fixed something on this car without (IMG:style_emoticons/default/sheeplove.gif) something else. If it's not one thing, it's another. (Or as Freud put it: If it's not one thing, it's your mother.)
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dr914@autoatlanta.com
post Apr 15 2010, 07:43 PM
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early cars two prong switch late cars single prong switch. the factory figured out that the switch can ground through the master cylinder!

QUOTE(flipb @ Apr 15 2010, 06:29 PM) *

My '74 has a 19mm Master Cylinder.

The dash warning light has been flashing incessantly - I disconnected it a while ago. Tonight I was busy breaking my horn mechanism in the steering wheel (IMG:style_emoticons/default/blink.gif) and I decided to try to reset the button on the MC to stop the flashing.

Here's the deal. With the car on the ground and a flashlight, I managed to find the reset button. Hit it, reconnected the warning light on the dash, and it now functions correctly. (stops when the parking brake is released)

However while I was reaching in there, I accidentally disconnected what looks like a Ground wire. I don't think I have any hope of finding where it connects without taking the car to a shop and getting it up on a lift, so...

What is the risk of driving it with the ground wire disconnected from the MC?

I don't think I've ever fixed something on this car without (IMG:style_emoticons/default/sheeplove.gif) something else. If it's not one thing, it's another. (Or as Freud put it: If it's not one thing, it's your mother.)
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McMark
post Apr 15 2010, 07:47 PM
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The wiring harness has two connections. Let the other one dangle. It was already there, you just didn't notice it before.
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jt914-6
post Apr 15 2010, 07:47 PM
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Is the wire connected to the master cyl. switch brown with a yellow stripe? It should be connected to it if your switch has a reset button. On the orignal switch there were two wires. The "ground" you think you disconneted is solid brown and IS a ground, except with the one wire switch it is not used...connects to nothing....
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flipb
post Apr 15 2010, 08:04 PM
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You all overestimate me.

I actually did screw up, I think. See below.

It looks like the solid brown ground wire was clipped by a PO, presumably when the 19mm MC was installed. The brown/yellow stripe is the one I accidentally knocked loose.

Anybody have a good photo to show where it connects? Alternately, is the risk of driving just that I won't get a warning light if I lose hydraulic pressure?

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McMark
post Apr 15 2010, 10:11 PM
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Hooks onto that big white thing.


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Eric_Shea
post Apr 15 2010, 10:38 PM
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No, no, no...

It hooks on right here:
Attached Image

There should be a male spade on the back of the tie-rod end there. (IMG:style_emoticons/default/huh.gif)

Geez Mark... full of bad advice today aren't we? (IMG:style_emoticons/default/w00t.gif)
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McMark
post Apr 15 2010, 10:49 PM
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(IMG:style_emoticons/default/blink.gif)

What the heck you talkin' bout..........
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Eric_Shea
post Apr 15 2010, 10:50 PM
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(sorry... couldn't help myself) (IMG:style_emoticons/default/biggrin.gif)
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Dave_Darling
post Apr 15 2010, 11:41 PM
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The electrical connection is on the same thing that the reset button was on. Looks like that white thing in the pic is it, but I could be mistaken.

If you want to be sure, remove the gravel pan so you can get a good look at everything. Maybe put the front end up on jackstands (so we know it's a real 914!) so you can really get a look.

--DD
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McMark
post Apr 16 2010, 10:48 AM
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QUOTE(Eric_Shea @ Apr 15 2010, 09:50 PM) *

(sorry... couldn't help myself) (IMG:style_emoticons/default/biggrin.gif)

I'll be sure to bring my folding chair to WCR! (IMG:style_emoticons/default/chair.gif)
HINT: You'll be the blue guy!
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