Not another cruise control issue. Brake switch issue, any help welcomed

[LBEEMING]

Hi Team, thanks for taking the time to look at this thread! I have a weird issue, which I suspect is some sort of grounding issue. Bentley manual says between pin 6 and ground, there should be infinite resistance. I'm getting zero resistance. Thing is, the brake lights are working. With ignition on the brake lights will turn on and off, but pin 6 won't show infinite resistance. Any clues on this? Anyone had a similar experience. I'm wondering if maybe one of the brake switches is broken. Still need to check this. Thanks.

[ant7]

Infinite resistance means its open circuit, ie; no reading, hope this helps.

Originally Posted by LBEEMING

Hi Team, thanks for taking the time to look at this thread! I have a weird issue, which I suspect is some sort of grounding issue. Bentley manual says between pin 6 and ground, there should be infinite resistance. I'm getting zero resistance. Thing is, the brake lights are working. With ignition on the brake lights will turn on and off, but pin 6 won't show infinite resistance. Any clues on this? Anyone had a similar experience. I'm wondering if maybe one of the brake switches is broken. Still need to check this. Thanks.

[FrankM_]

Bentley is wrong since between pin6 and ground you have the brake lights (so a few ohms max) if the brakes are not depressed. The brake switch will pull pin 6 up to 12v and the internal relay on the CC unit will see 12v on both sides of its coil and disconnect.


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[LBEEMING]

Originally Posted by FrankM_

Bentley is wrong since between pin6 and ground you have the brake lights (so a few ohms max) if the brakes are not depressed. The brake switch will pull pin 6 up to 12v and the internal relay on the CC unit will see 12v on both sides of its coil and disconnect.


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Thank you! I looked at the wiring diagram and thought this exactly. I also know the Bentley manual is wrong about the clutch switch test, I just thought surely not wrong on two test procedures! Thanks!

[ant7]

Not having a copy of the Bentley manual I can't comment on what should be on the pins you mentioned, hence my original brief response, good that Frank was able to point out the mistake in the Manual, could have spent a lot more time chasing your tail on that one!

Originally Posted by LBEEMING

Thank you! I looked at the wiring diagram and thought this exactly. I also know the Bentley manual is wrong about the clutch switch test, I just thought surely not wrong on two test procedures! Thanks!