Author Topic: Brake lights stay on.  (Read 2815 times)

Jeremy Parrett

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Brake lights stay on.
« on: August 11, 2017, 01:36:33 PM »
Lots of rain last night.  This morning I noticed the brake lights on the Beaver marquis were on. I powered up ,aired up  , cycled the brakes and they wont go off even after I powered off .  The lenses are getting real hot.
I have replaced the relay in the electrical bay #4 .It was warm.  Brake lights are still on so I disconnected the power to the relay for now.
« Last Edit: August 11, 2017, 03:16:02 PM by Jeremy Parrett »

Steve Huber Co-Admin

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Re: Brake lights stay on.
« Reply #1 on: August 11, 2017, 05:01:57 PM »
Jeremy,
Check to see if there is 12v to the relay trigger by putting a volt meter across the wires to pins 85 and 86. If you see 12v the relay is being told to close so your problem is before the relay, maybe brake switch itself. If no 12v there, check pin 87. If 12v there, problem is between relay and brake lights. Based on what you said, I suspect problem is between brake switch and relay, but check to be sure.
Steve
Steve
2015-          07 Contessa Bayshore C9,  400 hp
2013-2015: 00 Marquis Tourmaline, C12, 425 hp
2005-2013: 01 Contessa Naples, 3126B, 330 hp

Joel Ashley

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Re: Brake lights stay on.
« Reply #2 on: August 11, 2017, 11:09:19 PM »
Steve, wouldn't it be easy for Jeremy to check the brake pedal switch as a first step?  I've oft read about loose, misaligned, or broken switches there, and it would seem easy enough to examine;  could be the switch is just stuck closed there for some reason.  Not sure rain intrusion to the lamps would short them out if no power was from the relay to begin with.

-Joel
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Steve Huber Co-Admin

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Re: Brake lights stay on.
« Reply #3 on: August 11, 2017, 11:18:46 PM »
Joel, Jeremy,
Yes he could. The other check he can make is again in the electrical bay. TB1-7 (in diagram I'm using) is "Brake Switch Out. It is the input signal to the  Brake Light relay (pin 85 or 86). It will have 12v on it all the time IF the brake switch is misaligned or if the Retarder relay (R7 in my diagram) is stuck.
Steve
Steve
2015-          07 Contessa Bayshore C9,  400 hp
2013-2015: 00 Marquis Tourmaline, C12, 425 hp
2005-2013: 01 Contessa Naples, 3126B, 330 hp
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Jeremy Parrett

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Re: Brake lights stay on.
« Reply #4 on: August 12, 2017, 04:26:57 AM »
Joel and Steve
Great info. I will get on my crawler armed with voltmeter and check the brake switch.  I did disconnect the wires individually but the brake lights stayed on ; will check relay as well.
Thanks,  will keep you posted.  Jeremy

David T. Richelderfer

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Re: Brake lights stay on.
« Reply #5 on: August 12, 2017, 11:46:21 AM »
Another possibility, albeit remote, is if you have a trailer brake controller like our coach has, then it may be causing your coach's brake lights to stay on.  Recently our coach's brake lights were on while it was parked in our driveway.  The brake lights were on probably 95% of the time and would intermittently go off for a few seconds every now and then.  Anyways, here'e a link to the thread I started a few weeks ago... with the conclusion to the issue.

http://beaveramb.org/forum/index.php/topic,6925.msg49422.html#msg49422
2004 Beaver Marquis Sapphire

I had a dream... then I lived it!

Jeremy Parrett

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Re: Brake lights stay on.
« Reply #6 on: August 13, 2017, 10:26:51 PM »
Hi David,
  I don't have a trailer brake controller .  Ah well.....I'll keep at it till we get to Maudlin Service in Daytona Beach on the 17th . Perhaps they can fix it while the service the drive axle disc brakes.  Jeremy