You can't see me stopping - The 1947 - Present Chevrolet & GMC Truck Message Board Network

WB72 · 06-21-2011, 01:15 AM

My Brake lights just quit working.

Is there an easy, one man way to determine the part that is defective?

Brake switch
Proportioning Valve

Are these are the only things that I will have to check? What is the proceedure of checking them? Test light? Is it just that easy?

If the proportioning valve is defective, will I get any power to the brake switch?

Autoblueprint · 06-21-2011, 01:38 AM

Quote:

Originally Posted by WB72

My Brake lights just quit working.

Always check the fuse(s) first. If ok, then test for power in / out at brake light switch with test light ( check switch fore / aft adjustment too ). If switch powers ok, and adjustment ok, then problem is somewhere in harness from switch to bulb. Check bulbs first.

Problem most likely is a bad fuse or brake light switch.

Tx Firefighter · 06-21-2011, 05:13 AM

Prop valve has nothing to do with your brake lights.

The stop light switch that activates the brakes is under the dash on the pedal cluster.

eagleuh1 · 06-21-2011, 07:13 AM

Check fuse, check bulbs, check ground wires at back,Check harness at back is plugged in , no cuts in wires, check break pedal switch connector is plugged in good. Check that the pedal pushes on the little pin in the switch to turn on the lights.

Longhorn Man · 06-21-2011, 08:48 AM

check the parking lights, if they work, the fuse is fine
check turn signals, if they work, the bulbs are fine, as are the wires going the length of the truck.
check the switch. 2 wires, orange and white. Full time power on one wire, power on the other when the pedal is depressed
Everything tests ok so far, then you will 99% chance need a turn signal switch.
To check this, have an assistand looking at the tail lights, or you can back up to a wall/garage door at night and watch them in the mirrors. Engine on or off, key on or off, it doesn't matter. Hold the brake pedal down, notice if the brake lights are out. LIGHTLY wiggle the turn signal lever up, and then down, forward and back. If the brake lights come on at any point, then go get a turn signal switch.

gcburdic · 06-21-2011, 10:16 AM

Nice easy info there LHM!!! Thanks

WB72 · 06-21-2011, 10:23 AM

All great info, I will get working on it.

To confirm, the brake lights are the only thing that doesnt work, the signals do work, could there still be an issue with the turn signal switch?

coop34 · 06-21-2011, 11:52 AM

I just recently had a similar problem and replaced my turn signal switch just last night and the problem is gone. Check everything that longhorn suggestion and if they all checkout, get yourself a new turn signal switch.

ChevLoRay · 06-21-2011, 02:30 PM

Since your brake lights are the only thing not working, it would seem that the grounding for those bulbs is good.

But, for anyone who may have a problem with bulbs not working correctly, or all, just add checking your ground wire connections to LonghornMans' post.

Electricity is like water, it will seek the path of least resistance. If a path for a circuit can be made through another circuit, you'll have dim bulbs when it should be bright...or off, or it will work when it shouldn't....like the right side working when it should be the left...or both working when it should only be one working.

VA72C10 · 06-21-2011, 03:07 PM

Great info as usual from LHM...and I also agree with ChevLoRay on grounding. My bulb cups were loose in the rear of my 70. When the brake lights didn't work, I went back and went to loosen the lense and when I touched the screw the light came on. I turned off the lights, undid it all, cleaned connections, and reattached (tightly) and everything worked fine.
Also, there are ground straps between the body and frame and engine and frame and many times they can cause electrical issues that are hard to diagnose....

406 Q-ship · 06-21-2011, 04:50 PM

Quote:

Originally Posted by WB72

All great info, I will get working on it.

To confirm, the brake lights are the only thing that doesnt work, the signals do work, could there still be an issue with the turn signal switch?

Yes it still can be the turn signal switch. If you have power going in and out of the stop light switch on the pedal, the wire from the stop lamp switch to the steering column is not broken, and the turn signals work .....then you have a bad turn signal switch.

bosco200 · 06-21-2011, 04:52 PM

Its finally happen....someone ran out of brake light fluid.

eagleuh1 · 06-21-2011, 04:55 PM

Good info to know LongHorn Man. Hey, did you see the nice longhorn in my Petit Jean post. Sorry for the thread hijack WB72

fastwillie 696969 · 06-21-2011, 04:57 PM

Quote:

Originally Posted by Tx Firefighter

Prop valve has nothing to do with your brake lights.

The stop light switch that activates the brakes is under the dash on the pedal cluster.

good knowledge tx

WB72 · 06-22-2011, 08:30 AM

Thanks all. Gonna get a new switch. That should clear up the issue.
Posted via Mobile Device

06-21-2011, 01:15 AM	#1
WB72 Before and After Join Date: Feb 2000 Location: Leduc, Alberta CANADA Posts: 632	You can't see me stopping My Brake lights just quit working. Is there an easy, one man way to determine the part that is defective? Brake switch Proportioning Valve Are these are the only things that I will have to check? What is the proceedure of checking them? Test light? Is it just that easy? If the proportioning valve is defective, will I get any power to the brake switch? __________________ Not Grandpa's C-20 anymore... 383 Stroker 425HP, 485Ft/Lbs Lowered 3.5" Front / 5" Rear 66,000 miles. Alberta, CANADA

06-21-2011, 05:13 AM	#3
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: You can't see me stopping Prop valve has nothing to do with your brake lights. The stop light switch that activates the brakes is under the dash on the pedal cluster. __________________ I'm on the Instagram- @Gearhead_Kevin

06-21-2011, 07:13 AM	#4
eagleuh1 Registered User Join Date: Jul 2009 Location: Russellville, Arkansas Posts: 1,699	Re: You can't see me stopping Check fuse, check bulbs, check ground wires at back,Check harness at back is plugged in , no cuts in wires, check break pedal switch connector is plugged in good. Check that the pedal pushes on the little pin in the switch to turn on the lights.

06-21-2011, 08:48 AM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: You can't see me stopping check the parking lights, if they work, the fuse is fine check turn signals, if they work, the bulbs are fine, as are the wires going the length of the truck. check the switch. 2 wires, orange and white. Full time power on one wire, power on the other when the pedal is depressed Everything tests ok so far, then you will 99% chance need a turn signal switch. To check this, have an assistand looking at the tail lights, or you can back up to a wall/garage door at night and watch them in the mirrors. Engine on or off, key on or off, it doesn't matter. Hold the brake pedal down, notice if the brake lights are out. LIGHTLY wiggle the turn signal lever up, and then down, forward and back. If the brake lights come on at any point, then go get a turn signal switch.

06-21-2011, 10:16 AM	#6
gcburdic Restoration Virgin! Join Date: Jan 2008 Location: Huntersville, NC Posts: 8,298	Re: You can't see me stopping Nice easy info there LHM!!! Thanks __________________ Geoff with a G 1968 Chevy C10 SWB The Mistress 1972 Custom Deluxe C20 Suburban A Suburban Named Isabella 1966 Ford Mustang Mama's High School Graduation Present

06-21-2011, 10:23 AM	#7
WB72 Before and After Join Date: Feb 2000 Location: Leduc, Alberta CANADA Posts: 632	Re: You can't see me stopping All great info, I will get working on it. To confirm, the brake lights are the only thing that doesnt work, the signals do work, could there still be an issue with the turn signal switch? __________________ Not Grandpa's C-20 anymore... 383 Stroker 425HP, 485Ft/Lbs Lowered 3.5" Front / 5" Rear 66,000 miles. Alberta, CANADA

06-21-2011, 11:52 AM	#8
coop34 Registered User Join Date: Sep 2009 Location: Visalia, CA Posts: 247	Re: You can't see me stopping I just recently had a similar problem and replaced my turn signal switch just last night and the problem is gone. Check everything that longhorn suggestion and if they all checkout, get yourself a new turn signal switch.

06-21-2011, 02:30 PM	#9
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Re: You can't see me stopping Since your brake lights are the only thing not working, it would seem that the grounding for those bulbs is good. But, for anyone who may have a problem with bulbs not working correctly, or all, just add checking your ground wire connections to LonghornMans' post. Electricity is like water, it will seek the path of least resistance. If a path for a circuit can be made through another circuit, you'll have dim bulbs when it should be bright...or off, or it will work when it shouldn't....like the right side working when it should be the left...or both working when it should only be one working. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

06-21-2011, 03:07 PM	#10
VA72C10 VA72C10 Join Date: Mar 2008 Location: Midlothian, VA Posts: 25,269	Re: You can't see me stopping Great info as usual from LHM...and I also agree with ChevLoRay on grounding. My bulb cups were loose in the rear of my 70. When the brake lights didn't work, I went back and went to loosen the lense and when I touched the screw the light came on. I turned off the lights, undid it all, cleaned connections, and reattached (tightly) and everything worked fine. Also, there are ground straps between the body and frame and engine and frame and many times they can cause electrical issues that are hard to diagnose.... __________________ Looking for a 67-72 swb or blazer project in or around VA.

06-21-2011, 04:52 PM	#12
bosco200 Registered User Join Date: Dec 2009 Location: Ste. Genevieve, MO Posts: 526	Re: You can't see me stopping Its finally happen....someone ran out of brake light fluid.

06-21-2011, 04:55 PM	#13
eagleuh1 Registered User Join Date: Jul 2009 Location: Russellville, Arkansas Posts: 1,699	Re: You can't see me stopping Good info to know LongHorn Man. Hey, did you see the nice longhorn in my Petit Jean post. Sorry for the thread hijack WB72

06-22-2011, 08:30 AM	#15
WB72 Before and After Join Date: Feb 2000 Location: Leduc, Alberta CANADA Posts: 632	Re: You can't see me stopping Thanks all. Gonna get a new switch. That should clear up the issue. Posted via Mobile Device __________________ Not Grandpa's C-20 anymore... 383 Stroker 425HP, 485Ft/Lbs Lowered 3.5" Front / 5" Rear 66,000 miles. Alberta, CANADA



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