# Blinking brake dash light on 1990 3500



## Alaska Boss (Oct 8, 2005)

The brake light in the dash (gage cluster) of my 1990 Chevy 3500 has just started blinking,... I've had a number of Chevys now, & thought I had seen it all, but have never seen this before... didn't even know that the brake light could blink, and my shop manual doesn't say anything about it,... so, anyone know what sets the brake light off to blinking? Thanks :waving:


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## 92XT (Nov 30, 2007)

Do you use your parking brake frequently? 
If so , it may not be dis engaged all the way.
just enough for the light to blink.


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## LBZ_Dan (Feb 21, 2007)

Does your truck have anti-lock brakes? If there is a black box next to the master cylinder, then it does. These trucks had the Kelsey-Hayes RWAL system. They used the brake light in the dash to warn you of a fault in the system. It would flash codes with the brake light. Try this website, has some good info about the system: http://www.aa1car.com/library/abs_kelseyhayes_rwal.htm Hope this helps you.


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## Alaska Boss (Oct 8, 2005)

92XT;457710 said:


> Do you use your parking brake frequently?
> If so , it may not be dis engaged all the way.
> just enough for the light to blink.


Ahhhhh,.. nope, that's not it.....


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## Alaska Boss (Oct 8, 2005)

LBZ_Dan;457776 said:


> Does your truck have anti-lock brakes? If there is a black box next to the master cylinder, then it does. These trucks had the Kelsey-Hayes RWAL system. They used the brake light in the dash to warn you of a fault in the system. It would flash codes with the brake light. Try this website, has some good info about the system: http://www.aa1car.com/library/abs_kelseyhayes_rwal.htm Hope this helps you.


Thanks Dan,... that article had some good info about the brake systems in these earlier trucks. My brakes work fine & nothing has changed in that way,... (pedal pressure, etc), but something must have happened somewhere to trigger the brake dash-light system, to make it flash all day long without stopping. I have an OBD I scanner (pre-'96) somewhere, but I had thought those just pulled codes from the "service engine" light code system,... maybe that will tell me something. Thanks again.


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## Gmgbo (Jan 18, 2005)

Mine comes on like once a year. I unhook the battery and then pull the 2 wire harnesses that connect to the black box near the master cylinder, wait like 1 minute, and then hook it all back up. The light stays off for a year usually. Hope that helps.


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