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Old 01-18-2014, 11:10 AM   #262
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Join Date: Jan 2005
Location: Kalamazoo, Michigan
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Re: I suck at reading wiring diagrams..

Originally Posted by Steve-W View Post
Last night I was hooking up the wiring for the gauge cluster and I have a few questions.

in the EZ wiring manual it says there is a white wire called "brake switch" that connects to the steering column wires. first question is why?

The brake switch and the brake lights are powered by the always hot, orange wire, from the fuse panel, so the brakes will work when the engine is not running or the key is off.
The brake lights share the same wires with the turn signals lights, so the brake wires have to come through the turn signal switch. In order to do this, the brake lights need a source of power from the brake switch, and this is where the white wire comes in. It runs from the brake switch to the column connector and up to the turn signal switch.
If you look at the red square in your first post you can see the white wire running from the brake switch up to the column connector.

Also the brake light is designed to cut out when the turn signal is selected for the left or right side. Otherwise the brake lights would be on all the time while stopped and turning at a red light. In order to do this the brake lights have to go through the turn signal switch.

and secondly where does it end up? because it is among my cab wiring, but isn't mentioned anywhere else in the manual. SEE ABOVE

thirdly I'm confused because of the name: I have ofcourse the brake switch near the pedal who engaged the break lights when braking. but I also have the switch in my brake power distributor which turns on the warning light in the dash in case of a brake failure..(atleast I guess thats what it's for)

any help would be highly appreciated!

The brake warning light wire is a tan wire that runs from the brake proportioning valve to the gauge cluster plug and it is the ground side of the warning light. When the brake fluid gets low or a pressure variance occurs between the front and rear brakes the switch inside the BPV will ground and turn on the light in the cluster. You can check this by grounding the wire with the key on and watching the light . It should come on when you turn the ignition switch to start also. The factory wired it this way in order to test the light.
What else you got..........

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74 corvette convertible
1965 Harley sportster
1995 Harley wide glide

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