Another brake light problem

[dgs]

I've read the two recent posts on no brake lights and I'm still stumped. Here's the deal:

- Running lights work fine.
- Turn signals work fine.
- No brake lights.
- Good brakes adn MC is full.
- If I short a screwdriver across the switch terminals on the master cylinder with the wires connected, I get brake lights.
- If I pull the wires and put a nail in each socket and touch the nails together, I get brake lights.

So, that means I've got power to the switch and good connections to the switch. This would lead me to replace the switch, but I did that in 2002 with a brand new NAPA unit. (The NAPA guy said this switch was used for nearly every Ford from about 1940 to 1980!) The brakes lights were working fine after I put the switch in, I'm not sure when they quit.

I tried pulling the switch and filling it with brake fluid (although I just poured it in, I didn't have a syringe) adn that didn't help eitehr. Is there a way to bleed the system at the master cylinder? I di re-do the MC, all wheel cylinders and rubber lines back in 2002, perhaps there's a connection?

I'm stumped, any ideas?

[Alexander]

RE: Another brake light problem

Master cylinders can be bleed on a bench, but I do not think that air in the system is a problem here, since you have good working brakes. Either your brake switch has gone bad or there is an obstruction in the port for the brake switch.

Alexander
1959 Hardtop
1960 Golde Top

[JohnG]

RE: Another brake light problem

sounds like your switch died!

You can bench test it with some compressed air. Put a multimeter across the two leads - they should be open in Resistance mode. Apply air pressure into the hole where brake fluid would go. If it remains open (infinite resistance) then it's dead.

Personally, I keep a spare one around. I had two of them die on my motorcycle in the space of a year (identical setup)

I have heard, but not verified, that DOT 5 can cause one to die that was previously used with DOT 3.

John

[dgs]

RE: Another brake light problem

No DOT 5, I'm using DOT 3-4. I have the old switch, I'll try that one and check the port. The switch was less than $8, so I'll get a new one if that doesn't work. Seems odd that the switch would quit, but oh well.

Thanks.

[roadpatrol]

RE: Another brake light problem

Hi,
Did the brake lights work before you replaced the M/C? It is possible to bleed the M/C on the car, as a matter of fact I had to bleed mine to get it working, you just pump and hold, then crack the line at the M/C .after you get all the air then it would be a good idea to bleed the rest while you are at it. You might even be able to bleed the switch the same way. Hope this helps


Rick
60 Hardtop
Front Brakes
12.6 Volts

[Guest]

RE: Another brake light problem

Definatley sounds like the switch as you are getting good power to where you need it,. i have heard of these things going out at any time and sometimes jus for sitting around
m

[tarps3]

RE: Another brake light problem

I thought my switch had gone bad once, but as it turns out, the 90-degree push on connectors (the electrical plugs to the switch) were just worn. They weren't tight enough on the posts to provide a consistent contact.

I squeezed them slightly with some pliers, pushed them back on, and have had no problems since.

it's worth a try..

[dgs]

RE: Another brake light problem

It was the switch. $4.99 from Autozone and I've got lights again.

Thanks all.