1956 Parking Brake Dash light

Discussions related to braking systems.
PMCCTX
Posts: 46
Joined: Thu Apr 07, 2016 1:25 pm

1956 Parking Brake Dash light

Post by PMCCTX » Fri Jul 12, 2019 12:47 pm

Noticed that this indicator light stays illuminated, regardless of the brake being engaged or not. Assuming it's a contact point or switch, and ideas before I start digging? Also worth nothing that I believe the TL has stopped functioning, so curious if these two could be possibly related?

Howard56
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Joined: Mon Dec 24, 2012 11:35 am

Re: 1956 Parking Brake Dash light

Post by Howard56 » Fri Jul 12, 2019 1:51 pm

In the engine compt at the very end of the emergency brake ratchet mechanism is a round switch held by a bracket screwed to the ratchet mechanism. When the brake is released and handle is all the way toward the dash the ratchet end is moved so it pushes on the switch plunger and opens the light circuit. A small amount of movement of the handle outward moves the end of the ratchet away from the switch plunger and turns on the light. The bracket is only mounted at one end and space is very tight in that area so possibly the bracket has been caught or bent and the switch plunger no longer makes contact with the ratchet mechanism and is always out.

On the TL, do the brake lights work? The brake light switch going bad is the most frequent cause of no TL. Next is a blown fuse. There are two fuses in the same area as the emergency brake switch and while I can't remember where the emergency brake power comes from offhand, doubt the problems are related electrically since the emergency light works. Mechanically, there could have been something that was caught by the mechanism and maybe moved the switch or did something to a fuse. If that is all good could something have moved the on/off switch under the dash to off or a wire been pulled out of the switch.
Attachments
IMG_2317.jpg

PMCCTX
Posts: 46
Joined: Thu Apr 07, 2016 1:25 pm

Re: 1956 Parking Brake Dash light

Post by PMCCTX » Fri Jul 12, 2019 4:54 pm

Thanks Howard. The parking brake light was an easy fix, as I found the switch was out of alignment with the bracket.
The rear brake lights work fine. Going to check the fuses as I suspect, and hope that's the culprit.

PMCCTX
Posts: 46
Joined: Thu Apr 07, 2016 1:25 pm

Re: 1956 Parking Brake Dash light

Post by PMCCTX » Fri Jul 12, 2019 5:09 pm

Well since I have brake lights, I assume the fuses in the red and purple wires are both good. I checked the 2 green wires running to the under dash switch and they don't appear to be loose. Any ideas what to do next? Hopeful I can avoid having to open the TL control box.

Howard56
Posts: 1140
Joined: Mon Dec 24, 2012 11:35 am

Re: 1956 Parking Brake Dash light

Post by Howard56 » Fri Jul 12, 2019 6:07 pm

I think you will need to crawl under but you could get a meter and test the lt green wire at the on/off switch and if it is good then crawl under to check the lt green wire at the control switch middle terminal. If no power at the on/off or control sw then you need to trace the light green wire back to the brake switch to find the failure. It could be the brake sw is working at the Normally open contact but not the Normally closed which the TL uses -- or maybe not have a good connection at the plug lt green wire. If you have power at the center terminal of control sw the wiring, brake switch, and on/off sw are good.

Next test is use a small jumper wire and ground one end. Touch the other end to the pink or yellow wire next to center lt green to energize a direction solenoid. The motor should start to move as soon as the pink or yellow is touched. If it does, limit switches, solenoids and motor are good which leaves only the control sw. Oxidation of the contacts inside have been previous issues even on NOS switches because of old age or just sitting on the shelf.

If the motor does not move with grounding the pink or yellow wire then ground the blue or orange wire but only long enough to verify the motor moves since that test will bypass the limit switches. If either side fails to move with the pink or yellow test but does with blue or orange there is most likely a broken wire at the soldered connection at the base of that limit switch. If it fails to move with blue or orange then a bad connection at the solenoid or the solenoid or a wire to the motor or the motor itself.
Attachments
56 with manual TL switch.jpg

PMCCTX
Posts: 46
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Re: 1956 Parking Brake Dash light

Post by PMCCTX » Sat Aug 03, 2019 1:38 pm

Ok, finally received the headlight switch removal tool. After sliding the headlight switch back, my investigation revealed that there was a brown wire (red arrow) that was disconnected. There are TWO open plugs on the switch. (Green arrows) - I suspect that the switch is fine (headlamps and interior lighting works), so which female does the brown wire go into?

Also, still working on the TL. I have the blower unit out and found a green wire that was not plugged in. It appears that it was running somewhere below the exhaust manifold. Could this be the culprit to my TL woes?
HeadlightSwitch.JPEG
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TLwire.jpg

Howard56
Posts: 1140
Joined: Mon Dec 24, 2012 11:35 am

Re: 1956 Parking Brake Dash light

Post by Howard56 » Sat Aug 03, 2019 2:14 pm

The light green wire that is part of the TL in the engine compt starts at the brake light switch and goes into the loom where it travels inside to the on/off switch under the dash. Out of the switch and thru an inline connector where I believe it goes into another loom and down to the TL control switch.

There is another light green wire in the engine compt which I believe is a single loose wire and is part of the AC. That comes from the power relay under the dash and goes to the compressor clutch.

You didn't post a photo of the headlight switch but here is a photo showing terminal designations. There is a tan wire which is part of the courtesy lights and that may be the one you see. It goes on the end terminal labeled for courtesy light and turns the lights on when the knob is turned all the way to the left. If you have a two door, those have a small jumper assy on that terminal so more than one tan wire can plug in.
Attachments
headlight sw 55-6.jpg
Last edited by Howard56 on Sat Aug 03, 2019 2:23 pm, edited 1 time in total.

PMCCTX
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Joined: Thu Apr 07, 2016 1:25 pm

Re: 1956 Parking Brake Dash light

Post by PMCCTX » Sat Aug 03, 2019 2:23 pm

HeadlightSwitch.JPEG
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Howard56
Posts: 1140
Joined: Mon Dec 24, 2012 11:35 am

Re: 1956 Parking Brake Dash light

Post by Howard56 » Sat Aug 03, 2019 2:25 pm

The tan wire pulled out of the small inline connector which is part of the tan jumper on the courtesy light terminal.

PMCCTX
Posts: 46
Joined: Thu Apr 07, 2016 1:25 pm

Re: 1956 Parking Brake Dash light

Post by PMCCTX » Sat Aug 03, 2019 2:28 pm

So the green arrow in the center, correct?

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