No brake warning light solid or flashing in 1973--help please Options

[914xr75]

It's me again. A couple weeks ago the World helped me with proper bleeding of my daughter Lilly's car. Now I am trying to get the brake warning light to work before the WCR. It has never worked in the past nine years, flashing or solid.

I am not good with electrical issues. I know how to check my battery with a freebie Harbor Freight dmm, but that's about it. So here are the details.....New 17mm ATE master. Brown with yellow stripe wire connected to the new master. I have pushed the reset button. Brakes are properly bled and there are no leaks.

The turn signals work properly. The flasher works. The seat belt warning light has never worked for 9 years. i checked that the bulb is good for the warning light. All the terminals at the bulb base are connected. I think there are 3 spade connections.

I didn't see a fuse listed for the switch. Someone in a previous post mentioned a diode near the warning light. I'm hoping there is an easy fix for this problem or I will have to take it to an auto electrician. The warning light doesn't work for the e-brake as wall.

Thanks in advance for any assistance. Sean

[infraredcalvin]

Do you have a brake light switch at the base of you brake pedal? I forget if this is a 914 or 911 thing…

If so, check that the little lever is aligned with the tab on the pedal and being actuated….

[cgnj]

Brake lights or brake warning light? Two different issues.
Brake lights see the post above.
Brake warning light connection on MC, switch on emergency brake handle assy

[dtmehall]

(IMG:style_emoticons/default/agree.gif)

[914xr75]

It's the brake warning light. Sorry about that. MC is new. No leaks. Would a bad e-brake switch completely stop the warning light from working? The warning light does not go on at all.

[jim_hoyland]

I just went through the brake warning light issue too:
Pull out the gauge , remove the bulb holder with bulb.
Test the bulb 1st, either in the socket out . I use a 9 volt battery.
Test the ground wire to the socket, with e brake on, you should see continuity. If you get continuity and the bulb is good, test the other wire for 12v. With one probe on chassis ground and the other on the green/black wire you should get 12v ( Ignition switch has to be on) If your turn signals work, you should see 12v

[914xr75]

That sounds like good information. I’ll give that a shot Jim. Thank you. Gotta pull the 9 V battery out of my smoke detector.

[jim_hoyland]

That sounds like good information. I’ll give that a shot Jim. Thank you. Gotta pull the 9 V battery out of my smoke detector.

I started out by removing the switch under the Ebrake handle:
Test the switch that it works, I cleaned mine while out
Test the ground wire that goes to the switch

[dtmehall]

replace it. the part is cheap, and it isn't very robust

[Puebloswatcop]

From the fuse block...Fuse 9 feeds power to the fasten seat belt light via a black wire through the ignition switch. It then feeds the parking brake circuit via a brown and white wire. it also feeds the brake warning light and yes there is a diode in that circuit.

The brake warning switch should have 2 wires, I believe one is ground (brown wire) and the other I believe is a brown/white wire.

It really comes down to checking the #9 fuse, seat belt light, parking brake switch, or brake warning light switch and the brake warning light bulb itself. If all of the switches are good and the bulb is good that really only leaves 2 things left, a bad diode, or a broken wire. Those 2 things aren't very likely, but these cars are over 50 years old, so I would never discount any possibility.

Let me know what you come up with. If it will help I can send you a wiring diagram.

[cgnj]

914xr75 If your brake warning light is @12'oclock, it may have two bulbs.
Tools required; Philips screwdriver, 27mm socket and wrench, pliers,HarborFreight Alligator clips, Harbor Freight Logic probe or continuity tester or DVM. I'm lazy. I use a Logic probe because it is the most efficient in this case. Download 914 Current Flow diagram here. 1974 914 current flow
Remove combo gauge from cluster. YouTube removing gauges

You are interested in K7-44 Brake Warning Bulb, F6-44 Brake Warning Switch (located on Master Cylinder), and F9-61 Parking Brake Switch.

I do not see any diodes in this circuit.

Pm me if you need anymore help.

[Spoke]

It's the brake warning light. Sorry about that. MC is new. No leaks. Would a bad e-brake switch completely stop the warning light from working? The warning light does not go on at all.

The warning switch on the MC and the ebrake switch are in parallel. If either one grounds out the warning light will come on.

The MC warning switch is difficult to test. Not sure if there's a way to make the warning switch close w/o screwing with the brake system to cause a fault. The reset button only resets the switch after a fault. A simple way to test the warning light is to short the 2 spades of the warning switch together and see if the light comes on. Does your MC switch have 2 spades or 1 spade?

For the ebrake switch, remove the switch and short the wire to the chassis. This should cause the warning light to light up (car is running). If it does light up, then your switch needs work.

[jim_hoyland]

When I removed the eBrake switch there’s was a fair amount of gunk under the mounting surface and the switch.
Took some Qtips and rubbing alcohl and got the crud up, then sanded the mounting hole area with the dremel.
Worked good and I no longer have to wiggle the eBrake handle down to extinguish the brake light… (IMG:style_emoticons/default/smile.gif)

[dtmehall]

where did that 'gunk' come from. my 73 was clean of 'gunk' when i replaced that switch.

do you have a hole in your wheel well?

[914xr75]

Thanks for all the info. I'm getting up early tomorrow to solve some mysteries.

[Spoke]

where did that 'gunk' come from. my 73 was clean of 'gunk' when i replaced that switch.

do you have a hole in your wheel well?

My switch was a mess too. Just dust residue, dirt and 40 years of wear and tear. The switches are open case and the contacts are open with the handle down allowing any debris and oxidation to get between the contacts.

[914xr75]

@jim hoyland @Puebloswatcop I still haven’t figured out how to summon people that have helped me out. Don’t know how to underline names. But anyways I went at it today. Put a 9volt battery to the bulb and it is good. I don’t have any continuity from the ground wire with the E brake on. Also did not get 12 V from the other wire connecting to the bulb. This would be with the ignition on.

The number 9 fuse is good. Cleaned and lightly sanded the contact for the handbrake switch. Went looking at the couple wire areas that have been touched by the po. The picture with the red wire I believe goes to the radio. The solid white and solid brown wire that end in female spade terminals, and is not connected. I do not know what that is.

I’m starting to think it’s my turn signal switch. My turn signals work, but when you turn them on and look at the indicator, both right and left indicators blink at the same time. This would be for right and left turns. One of the directions does not cancel itself out. Since it is Father’s Day, and I didn’t want to be in the garage all day long, this is all I have. Any ideas?

[914xr75]

[jim_hoyland]

Oops

[jim_hoyland]

“Put a 9volt battery to the bulb and it is good. I don’t have any continuity from the ground wire with the E brake on. Also did not get 12 V from the other wire connecting to the bulb. This would be with the ignition on.”

Try grounding the light to chassis with ignition on.