1964 Thunderbird Brake light issues

[Shadrack]

I would guess, based on information from 40birds, that connection there was an attempt at bypassing the brake switch relay. If you check continuity from those back to the green-red wire at the fuse box you may find it is the wire you are looking for. The other wire you have there probably goes to the brake light switch.

I have updated the sketch I drew and I hope this helps you a little bit.
View attachment 3887

First Steve....let me say....this is like PURE gold! Thank you so much for all this help!! I will check continuity on the wires ASAP.

I am trying to look at this and use it as a model:
https://www.macsautoparts.com/ford_...relay-harness-kit-1964.html?ndlvid=7b1-22eba8

It would seem I am missing a breaker - anyway to piggyback off another?

This page contains affiliate links for which I may be compensated. As an eBay Partner, and Amazon Associate I may be compensated if you make a purchase at no cost to you.

 

[Shadrack]

At first I didn't understand but now I think I do. You are referring to that open rectangular hole in the fuse box picture that nemesis posted. I guess there is supposed to be a 15A relay in that position and that it is for the brake light circuit. Then after reading what nemesis wrote in another post (#40) it sounds like someone tried to operate the brake light circuit by jumping from the starter solenoid with a 15A in-line blade fuse rather than from the fuse box.

Is it possible for something like this to work? My stop relay is new - it gave me back my taillights, but not break lights - and this fuse was in place then. Could I just have a bad switch? My master cyl looks like it has seen better days but still works.

 

[fordrodsteven]

Is it possible for something like this to work? My stop relay is new - it gave me back my taillights, but not break lights - and this fuse was in place then. Could I just have a bad switch? My master cyl looks like it has seen better days but still works.

Those hydraulic brake light switches are known to be prone to fail. You can check that by jumping the two leads at the switch together to see if it makes the brake lights work. I do not understand how changing a stop relay would make the tail lights work. Remember I said they are different circuits. The taillights will come on / off from the headlight switch. The four way flashers are a separate circuit. The brake lights are a separate circuit that feeds through the directional switch in the steering column. What exactly is this "stop relay" you say you replaced?

 

[64ZCODE]

Is it possible for something like this to work? My stop relay is new - it gave me back my taillights, but not break lights - and this fuse was in place then. Could I just have a bad switch? My master cyl looks like it has seen better days but still works.

You can test the switch for continuity while someone presses the brake pedal. And what Steven just said above.

 

[fordrodsteven]

You can test the switch for continuity while someone presses the brake pedal. And what Steven just said above.

X2

Nemesis.... Take your time, be patient and diligent. You will get it sorted!

 

[Shadrack]

Those hydraulic brake light switches are known to be prone to fail. You can check that by jumping the two leads at the switch together to see if it makes the brake lights work. I do not understand how changing a stop relay would make the tail lights work. Remember I said they are different circuits. The taillights will come on / off from the headlight switch. The four way flashers are a separate circuit. The brake lights are a separate circuit that feeds through the directional switch in the steering column. What exactly is this "stop relay" you say you replaced?

I got it from Larry's I think, the tail lights came to life as soon as I plugged it in, I cannot explain it - maybe dumb luck? coincidence. It had been several days since I had worked on the car.
https://www.larrystbird.com/product/relay-6366-top-64-stop-light/

This is the same one they say is needed for the brake lights - here is the harness and all that:
https://www.macsautoparts.com/ford_...relay-harness-kit-1964.html?ndlvid=7b1-22eba8

I am really wondering how my car has not caught fire or has learned to drive itself with all these hack jobs.

 

[Shadrack]

Those hydraulic brake light switches are known to be prone to fail. You can check that by jumping the two leads at the switch together to see if it makes the brake lights work. I do not understand how changing a stop relay would make the tail lights work. Remember I said they are different circuits. The taillights will come on / off from the headlight switch. The four way flashers are a separate circuit. The brake lights are a separate circuit that feeds through the directional switch in the steering column. What exactly is this "stop relay" you say you replaced?

So just, take a piece of wire or copper and go across the leads? I am so sorry guys - I am new to all of this and you have been so patience and kind. Sincerely, I appreciate it.

 

[Shadrack]

You can test the switch for continuity while someone presses the brake pedal. And what Steven just said above.

I will let you all know what I find. I am wondering, aren't there kits out there that use a sensor to detect pedal travel and hook into your brake system? I am sure, between all of us, we will get it sorted (a million thanks) but just wondering.

By the way, the battery, I bought a 72 series BIG dude, they were trying to sell me this one that had 500 cca....I was like, nope I want the big one🙂

 

[64ZCODE]

I will let you all know what I find. I am wondering, aren't there kits out there that use a sensor to detect pedal travel and hook into your brake system? I am sure, between all of us, we will get it sorted (a million thanks) but just wondering.

By the way, the battery, I bought a 72 series BIG dude, they were trying to sell me this one that had 500 cca....I was like, nope I want the big one🙂

Nothing like cold cranking amps🙂

 

[fordrodsteven]

So just, take a piece of wire or copper and go across the leads? I am so sorry guys - I am new to all of this and you have been so patience and kind. Sincerely, I appreciate it.

I frequently use paper clips. Just make sure they don't have the plastic coating on them. I have a box of paper clips in my automotive electrical tool box. Yes I have multiple tool boxes! LOL (house electrical, house plumbing, automotive electrical, auto body, automotive testing equipment, automotive brake tools)

 

[fordrodsteven]

I will let you all know what I find. I am wondering, aren't there kits out there that use a sensor to detect pedal travel and hook into your brake system? I am sure, between all of us, we will get it sorted (a million thanks) but just wondering.

Actually there is a mechanical brake light switch that mounts under the dash and hooks to the brake pedal. When you step on the brake pedal it actuates and lights up the brake lights. Mid-60's ford. Like a Galaxie, Fairlane, Mustang. I think there is even an aftermarket adaptable mechanical brake light switch available. Some guys use switches off of motorcycles also.

 

[Shadrack]

I frequently use paper clips. Just make sure they don't have the plastic coating on them. I have a box of paper clips in my automotive electrical tool box. Yes I have multiple tool boxes! LOL (house electrical, house plumbing, automotive electrical, auto body, automotive testing equipment, automotive brake tools)

Hey Steve!

I did stick a piece of copper in the boot that goes across the leads - I bridged the inside of the boot in other words. No one pressed the brake pedal because MAC's tech guy said just bridging the leads in the boot should trigger the light.

Should I bridge it again and press the brake pedal? I will say that when it was bridged the last time and it dropped on the fender it sparked and blew that 15amp fuse.

So, just to make sure, use the copper, bridge the inside of the boot (connector that goes on switch) and press the brake pedal?

I will let you all know how it goes. Thanks again - hoping we can get this all fixed up.

 

[fordrodsteven]

First Steve....let me say....this is like PURE gold! Thank you so much for all this help!! I will check continuity on the wires ASAP.

I am trying to look at this and use it as a model:
https://www.macsautoparts.com/ford_...relay-harness-kit-1964.html?ndlvid=7b1-22eba8

It would seem I am missing a breaker - anyway to piggyback off another?

In looking at the fuse box schematic I drew up I would say you could tap (piggyback) off of the 20A relay that feeds the horn/window/ seat. Very little chance you would ever actuate everything at once and overload that relay. I would probably also stick an in-line 15A fuse in the circuit because it was originally hooked to a 15A relay. Just make a small jumper (from the 20A relay) with a 15A in-line fuse and then connect it to the green red wire. But first test the wire to insure it is not improperly hooked up to anything else. Remember I said to check for continuity from that lug and out to the wire you have that is out under the hood in your other picture (post #28} (not the one that is connected to the starter solenoid but the other one)

 

[fordrodsteven]

Hey Steve!

I did stick a piece of copper in the boot that goes across the leads - I bridged the inside of the boot in other words. No one pressed the brake pedal because MAC's tech guy said just bridging the leads in the boot should trigger the light.

Should I bridge it again and press the brake pedal? I will say that when it was bridged the last time and it dropped on the fender it sparked and blew that 15amp fuse.

So, just to make sure, use the copper, bridge the inside of the boot (connector that goes on switch) and press the brake pedal?

I will let you all know how it goes. Thanks again - hoping we can get this all fixed up.

No need to step on the brake pedal for that connection you made. The bridge actually completes the circuit as if it sees pressure at the brake light switch. When you make that bridge the brake lights should go on (unless you have a blown fuse)

If you want to check the switch you have to do what 64zcode said earlier (post #46). You have someone depress the brake pedal and check for continuity across the two poles on the switch.

 

[Shadrack]

No need to step on the brake pedal for that connection you made. The bridge actually completes the circuit as if it sees pressure at the brake light switch. When you make that bridge the brake lights should go on (unless you have a blown fuse)

If you want to check the switch you have to do what 64zcode said earlier (post #46). You have someone depress the brake pedal and check for continuity across the two poles on the switch.

I did the bridge test and had no brake lights, so I am assuming a fault in the wiring. Somewhere - it's very odd. I think power is getting to it because when it touched the fender well it sparked and blew the 15amp fuse - I just didn't have any brake lights. I did not try a continuity test, I will have to do that see what happens. I am really starting to wonder what the heck they did to this car. It seems like it would have been easier to fix the selector and ignition instead of hacking it all up. I really appreciate the help guys! When I get some time I will go start to trace the wires - I think at this point I am going to consider running new wires - I just have to get the time and of course the knowledge - still unsure.

 

[fordrodsteven]

Have you checked the bulbs? Sometimes if a system gets shorted it can blow the filament in the bulb. They are supposed to be double filament bulbs. One filament is for taillights and the other (brighter larger) is for the brake/turn/emergency. I think the bulbs are part number 1157

 

[fordrodsteven]

I did the bridge test and had no brake lights, so I am assuming a fault in the wiring. Somewhere - it's very odd. I think power is getting to it because when it touched the fender well it sparked and blew the 15amp fuse - I just didn't have any brake lights. I did not try a continuity test, I will have to do that see what happens. I am really starting to wonder what the heck they did to this car. It seems like it would have been easier to fix the selector and ignition instead of hacking it all up. I really appreciate the help guys! When I get some time I will go start to trace the wires - I think at this point I am going to consider running new wires - I just have to get the time and of course the knowledge - still unsure.

When you start to trace wires I recommend stating at the connector near the steering column where the wires come together to feed up the column into the directional. There you can verify wires coming to the connector from the body harness. You can also check the circuit from the other half of the connector for proper function of the directional / brake light circuit. Just unplug the connector and we can work to figure out what is happening at each side of the connector. Wiring diagrams show which wires do what. Just use the multimeter (and test light) and check continuity of the different wires when the directional is in center position and when it is in up or down position. If that checks good then your issues are elsewhere and we will help you find them. You may be able to sort out what is at the connector coming from the body harness and narrow it down pretty quickly if the directional switch checks okay.

What do you still need working to pass that inspection?

 

[Shadrack]

Hey Steve,
Sounds like a solid plan, I will start getting after it ASAP. Thank you all so much - this is the last thing I need working to pass inspection, I have everything else sorted - much of it thanks to you all!! I think I am going to perform a continuity test between that hanging red/green wire near the fuse box and the boot that covers the switch. I suspect they are connected.

 

[fordrodsteven]

Hey Steve,
Sounds like a solid plan, I will start getting after it ASAP. Thank you all so much - this is the last thing I need working to pass inspection, I have everything else sorted - much of it thanks to you all!! I think I am going to perform a continuity test between that hanging red/green wire near the fuse box and the boot that covers the switch. I suspect they are connected.

I'm not too sure of that. I suspect that the wires out at the fender are the "go- around" for the brake lights. The reason I think they did it is because they could not find a replacement 15A relay for the fuse box. (That spot where the open hole is). They didn't think to make a tap off of the 20A relay as I suggested to you earlier. It would have been much quicker and cleaner.
Here's what I think you will find; the go around to get power for the brake lights is the wire that now feeds from the starter solenoid to that connection out at the fender. Then through the hydraulic brake light switch and back through the firewall to under the dash. Under the dash I think you will find the green wire that feeds into the connector going up to the steering column is cut and connected to the wire coming from that connection at the fender. I'm not 100% sure but I will probably have to go back and look at some of your pictures or ask you to give us a better idea of how things look at the fender and under the dash.

 

[fordrodsteven]

I did the bridge test and had no brake lights, so I am assuming a fault in the wiring. Somewhere - it's very odd. I think power is getting to it because when it touched the fender well it sparked and blew the 15amp fuse - I just didn't have any brake lights. .

I'm thinking you and I may have gotten wires confused. At this point please disregard post #61. Consider this:
I think the wire at the fender that had the 15A fuse in it is actually probably now the power line feeding to the brake light hydraulic switch. (or it could be for something else... at this point we really don't know) I may have even gotten it a little screwed up in my last post to you. I think if you bridge the two wires up at the fender (where the fuse was) all you are doing is eliminating a fuse and making a direct wire connection. I would say hook those wires at the fender back up with a fuse in there and then go to the plug (boot as you call it) right at the brake light switch and bridge that connection there. This is when your brake lights should come on. If the brake lights do not come on then there is still a wiring issue someplace that will have to be tracked down. I think we already covered how to check the brake light switch by checking continuity across the switch with the brake pedal depressed.