No brake lights

[JeffAS]

I have read some of the other thread about this problem, but I am not having any lock, I have running and turnsingles but no brake lights, one of the other thread said to check the brake switch by the airpack, but I can not find any switch

 

[Ferroequinologist]

It is a round pressure switch, with two wires. There are two types- the old hydraulic type, and the newer air type.

If you need one in a hurry, you can rob the one from behind the dash, attached to the air shift control (if the truck is air shift) all that one is for is to turn on the indicator light.

 

[Ferroequinologist]

It will look like one of these-

 

[JeffAS]

Where are they located at I found some wires that are unplugged right under the master clyinder but there is no round pressure switch, would someone have removed it and just put a plug in its place

 

[G-Force]

Maybe thats why you don't have brake lights.
Tie the two wires together and see if your brake lights go on.
But first check them with an ohm meter to see if one shows continuity to ground with the switch off. Then check if one has voltage with the switch on.

 

[JeffAS]

From the looks of the wire and plug it looks like it is the black switch in your Photo, where can you pick one of those up

 

[clinto]

The wires going in and out will be circuit #75 I think.

 

[JeffAS]

Is this where it should be

 

[WillWagner]

Yup, supposed to be there. Saturn has the air side conversion kits. Get one, they are mo better.

 

[JeffAS]

Do you have the info on that conversion kit, part number, would like to see some photo's

 

[WillWagner]

http://saturnsurplus.com/m35/5025.jpg

It will be on the 1st page under M35 and labeled "brake switch upgrade kit"

Here's the place,

Saturn Surplus --> Saturn Surplus on the Web!

 

[BlizzardX23]

Maybe thats why you don't have brake lights.
Tie the two wires together and see if your brake lights go on.
But first check them with an ohm meter to see if one shows continuity to ground with the switch off. Then check if one has voltage with the switch on.

Neither of mine show continuity to ground with switch off

I dont know who did this hack job on the wires before I got the truck...but geez!!!

..so, I should have continuity to ground with switch off? I know they are hot when the switch is on, because I had my lights on when I got under the truck and traced the wires down to that spot, when I moved them, they grounded out lol...made me jump

 

[G-Force]

One should be hot with the switch on. The other should show continuity to ground through the bulbs. If you are feeling brave touch them together with the switch on. If you get a real BIG spark its a dead short. If you get a small spark, have someone look at your brake lights to see if they go on. I wouldn't leave them hooked together unless you are sure that the brake lights come on. If there is a short and you leave the wires hooked up lets say to crawl from under the truck to see if your brake lights are on you could fry the wire in the harness,

 

[BlizzardX23]

OK...so, with my problem (pic posted above)....all I need, to fix my break light wires and break system is this??

http://saturnsurplus.com/m35/5025.jpg

 

[Yohan]

I bought the upgrade above and I still don't have brake lights! I just need more time to figure it out. And warmer weather, yeah... warmer weather...

You should get the upgrade anyway, whether you get lights or not afterwards.

 

[dabtl]

I bought the upgrade above and I still don't have brake lights! I just need more time to figure it out. And warmer weather, yeah... warmer weather...

You should get the upgrade anyway, whether you get lights or not afterwards.

Grounds. Check the grounds and look for wiring shorts.

On the second deuce I changed out every lock washer for new ones, from Grainger, and wire brushed the rust from the area around the new bolts I installed also. Very dependable lights now.

 

[rrrr]

I had the same problem. Check the 3 pole light switch. Make sure the connector on the back is tight. Also make sure the connector on the turn signal and flasher box under the hood is also tight. Took me forever to figure out that two loose connectors made my brake lights intermittent. GOOD LUCK.

The brake light wiring runs through these three units !

 

[Yohan]

I had the same problem. Check the 3 pole light switch. Make sure the connector on the back is tight. Also make sure the connector on the turn signal and flasher box under the hood is also tight. Took me forever to figure out that two loose connectors made my brake lights intermittent. GOOD LUCK.

The brake light wiring runs through these three units !

I pulled my switch and checked all the contacts with my meter per an article I found on here and all was good. My signals are still intermittent after pulling the blinker lever and cleaning the contact with the steering column. I think my brakes are a ground issue, though. I've searched all of the threads for ideas for fixes, just need the time and weather to start the process. Thanks for all of the help!

John

 

[dabtl]

I pulled my switch and checked all the contacts with my meter per an article I found on here and all was good. My signals are still intermittent after pulling the blinker lever and cleaning the contact with the steering column. I think my brakes are a ground issue, though. I've searched all of the threads for ideas for fixes, just need the time and weather to start the process. Thanks for all of the help!

John

Each brake light and signal light is grounded at the base of the light fixture, whether on the fender or at the rear, by the mounting bolts. They rust. The inside/outside star washers rust. Get new mounting bolts, clean the bolt sockets also, and new inside/outside star washers to install after wire brushing the mounting surfaces. If they still act up, you have either worn wiring or loose connections between the junctions.

 

[Yohan]

Thank you, dabtl. I will check all of these. Maybe it's just me, but it always seems that after the truck has run a while, the turn signals will work??? I'll be checking these grounds and seeing what I can find.

Would the flasher/turn signal box under the hood have any affect on the brake lights? Sounds like yours may have...