brake light came on in my 88 k1500 but why?

[RetroC10Sport]

I have the OBD 1 GM cable for my laptop to check SES and ABS codes...But it does you no good here, huh....

 

[RetroC10Sport]

It's the brake and abs lights on? If so, pull the abs fuse and the brake light should go off.

 

[Swims350]

It's the newer body style not the squarebody style as for abs I don't think it's just called rear wheel anti lock. I think abs is all four or newer style. I don't know what the light says whether it's abs or brake I think it's brake only, but the e brake is unplugged since it would come on after I cut the cable sine the pedal wouldn't stay up.

I can jump the terminals with a wire and read the codes via the light, gonna do that tomorrow.

 

[HotRodPC]

Ahhh OK, was thinking you were talking about K5 or Burb.

 

[Swims350]

nah that's why I put it in the other vehicles section. It's an 88 k1500 1/2 ton short bed reg. cab 350 tbi th350 trans(I put in) was 700r4 and np241 t-case, 3.42 gears, small tires, no lift, SOB hit the ds and ran, it's dirty. LOL.

 

[HotRodPC]

I'm probably smokin crack then to even think about helping on this one. I know some about those models and even less about the 4x4 models. But I am fairly certain if its Rear ABS Only, the wheel sensor is a ring insdie the rear end on the carrier to the best of my recallection. But you are saying your Brake light is on, not the ABS light. There should only be 2 things that operate your brake light. The E brake and the lower pedal travel which is usually in the prop valve even then. It just located in a differant spot on the 88 up. It could also come on in succesion with another light and could be part of a code too. Have you checked your E brake switch to make sure its not defective. I'd think disconnecting the E brake cables would make more sag in that pedal and that might bring it on? I'd check the switch at the E brake if the brakes are working good.

 

[davbell22602]

Well let know if it works or not Swims350.

 

[Swims350]

yea the e brake pedal did bring it on awhile back after I cut the cables but I unplugged that a long time ago and it stopped. every part of the rwal or rear wheel antilocks only throws a code thanks to dave's write up, so I gotta go pull some codes and see what comes up.

 

[Swims350]

well I got a 10 count 9 quick flashes and the last was a long one.

brake lamp circuit. great lol another electrical issue. I was hoping for a bad dump valve and throw the junk away LOL.

Well guess I better see if the lights are working for the brake lights or if something got messed up down below and fuses.

 

[jake wells]

Mine was on all the time in my 78. I changed the proportioning valve and master cylinder.

Since the light usually indicates you have internal issues with those two items usually the problem is leak down.

happens with new vehicles even. Ever since i changed mine the light went off and my brakes are better than ever!

just changed those items it worked for me

 

[crazy4offroad]

Weak pedal in comination with the brake light suggests to me a bubble in the system that may have worked its way to the proportion valve. For ***** and grins try unplugging the prop valve wire and see if it goes off.

 

[HotRodPC]

Or, simply bleed the brakes. Bleeding the brakes, will allow the prop valve to reset itself. Apparently there is a vavle or piston in the prop vavle, that when you bleed your brakes, it alllows it to move. When it moves, and you are done bleeding, it supposed to go back to its home position and it might shut the light off.

 

[Swims350]

It was the brake light or lamp circuit, and the pressure and pedal feel hgas been the same since I put the new calipers and wheel cylinders on. I did it enough I know there was no air in the system.

Someone had said there were 3 stages to these new lights and they are completely right, the brightest stage is the e brake or something with it or the pedal,

the 2nd brightest is the prop valve and pressure,

3rd. like mine is the anti lock crap and is the dimmest and mine sure is.

I need to try and adjust the brake light switch and if not that, then change it.

 

[HotRodPC]

yeah, the info I am giving is directly related to square body and NON ABS systems. I know on a truck I had, the brakes were all new, front and rear, all was wonderful. And the brake light was on. Someone told me to bleed the brakes again, so the prop vavle would swing and reset itself. So I did and sure enough the light went off. Just needed for the prop vavle piston or vavle to move in the cylinder and it shut the light off.

 

[89Suburban]

It was the brake light or lamp circuit, and the pressure and pedal feel hgas been the same since I put the new calipers and wheel cylinders on. I did it enough I know there was no air in the system.

Someone had said there were 3 stages to these new lights and they are completely right, the brightest stage is the e brake or something with it or the pedal,

the 2nd brightest is the prop valve and pressure,

3rd. like mine is the anti lock crap and is the dimmest and mine sure is.

I need to try and adjust the brake light switch and if not that, then change it.

No ****? The actual dummy light has different brightnesses for different issues? Damn, that's good to know. I never heard of that but that could really help with troubleshootin.