75 CJ-5 Brake Light Anomaly

Fletch8672 · 02-12-2009, 09:43 PM

Disclaimer:
I know it's probably been run into the ground and I've researched it on here before I asked but couldn't find anything pertaining to my problem. Therefore, "I'm sorry" in advance....

Problem: Brake Lights don't work when pushed in. All other lights & signals work (front & rear, high/low, hazards) but when I push the brake pedal... nothing. When the lights are off... no brakes. When I turn on the lights....no brakes.

I've changed all bulbs, checked/replaced all fuses, replaced hazard & turn signal relays and still nothing. I'm thinking the brake switch but I don't know where it's at nor can I find it. I can take pictures if that'll help and post them here.

Any & all help is GREATLY appreciated.

GreenCJDan · 02-12-2009, 09:58 PM

It does sound like the switch since the turn signals and the flashers work. The brake light switch on a 75 is located just north of the brake pedal. If you follow the pedal mechanism up you will see two wires coming out of a box connected to the pedal lever. These can be tested with a volt meter. The most common problem would be a lack of a good ground. See if you can find the switch, and see if the wires are connected properly, this is a good starting point

**Coiz** · 02-12-2009, 10:48 PM

This is from a 79 but I assume they are the same. When you press the pedal, the white plunger springs out connecting the contacts allowing current to flow to the lights. The entire switch screws in and out for adjustment. See if the plunger moves freely and it should have continuity with an ohm meter when extended.

Oily · 02-12-2009, 10:57 PM

Quote:

Originally Posted by GreenCJDan

If you follow the pedal mechanism up you will see two wires coming out of a box connected to the pedal lever. These can be tested with a volt meter. The most common problem would be a lack of a good ground.

No ground issues with this switch. It just allows the hot wire current to pass through.
As Coiz mentioned, it is adjustable.

only in a jeep cj · 02-12-2009, 11:15 PM

I think that on the 75 CJ, it was a pressure switch on the brake lever pivot pin (down and to the left of Coiz picure). 2 wires going to it.

CJ258 · 02-13-2009, 12:26 AM

My '74 has a really different switch. It attaches to the push rod and likes to flop around and swing downwards. I replaced it with an OEM unit from Kragen that failed a few months late. The one I have now is from NAPA and mount on the column with a lever on the brake pedal so that when depressed the switch lever activates the lights. I could get the plug out of the Master cylinder or I would have used the press. switch.

Fletch8672 · 02-13-2009, 11:53 AM

I checked the brake pedal, per Coiz's picture, but there was nothing that looked like that around the pedal, so I followed the pedal thru the firewall to the brake fluid reservoir.

Then the 2 hoses on the left of the reservoir to what I think is the brake switch

There are no other wires around or even long enough to reach down there.

incynr8 · 02-13-2009, 12:00 PM

the switch on the combination valve is for your brake warning light.

Oily · 02-14-2009, 07:44 AM

Did the brake lights ever work ?
The switch assembly may have come loose and is hanging. If not you may not have had one but, you should have the wires/plug for it. There would be two wires and you can make a connector and just plug one into the other to see if the brake lights work.

Fletch8672 · 02-14-2009, 06:32 PM

Still no lights and I've checked almost everything. I'll crawl under again tomorrow and check for hanging wires but I can't understand why there's no wire going to the brake switch?!?!~ Just puzzles me...

crusty75 · 02-14-2009, 07:13 PM

The switch on a 75 is located above the brake pedal, near the pivot under the dash. The switch is powered from the turn signal switch. Follow the wires from your turn signal switch under the dash until you come to the "pyramid connector". You will know it when you see it, it is a perfectly descriptive name.

If your switch is missing, go to NAPA and get a new one, they are about $15. you should find the power wire hanging loose somewhere from the pyramid connector, and the wire that leads back to the lights should be hanging near the brake pedal somewhere. Both wires use common spade connectors. After you get the switch installed, if the new switch doesn't work, pull the pyramid connector apart, and clean the corroded contacts. You should be good to go, providing you have good wiring at the rear of the jeep.

Edit to add: The switch looks nothing like the pic posted above, that is for a post 76 jeep. The switch looks like a small rectangular box, with two spade terminals. It slides over the pivot, and is held in place with a cotter pin. (or in my case, a finishing nail)

6leafclover · 02-14-2009, 08:18 PM

mine on the 74 looks like the one above on the pedal assembly except its mounted lower so that the pedal arm itself hits the switch, the one on the block with the brake lines is for the warning light and has nothing to do with brake lights in the rear just the light on the dash, i dont even have that switch on mine as the warning light was optional in 74 and maybe other years

mckenziemc · 04-02-2009, 09:03 AM

I have the exact same problem. I am 90% sure it is the Spartan turn signal switch on the steering collum. I have traced power from the brake light switch on the peddal assembly to the wiring harness that goes to the turnsignal switch and verified that power does not come back. I am looking for a source for the switch now. I will let you know what I find out.

Mike Romain · 04-02-2009, 09:18 AM

Quote:

Originally Posted by Fletch8672

Still no lights and I've checked almost everything. I'll crawl under again tomorrow and check for hanging wires but I can't understand why there's no wire going to the brake switch?!?!~ Just puzzles me...

When the wire in the combination/proportioning switch in that photo is disconnected, that implies the brakes failed so the previous owner disconnected the warning light so a cop wouldn't tow him or to sucker the poor next owner. That switch sets off a red light on the dash when the pressure isn't right or when there is a leak.

It looks like the wire harness piece to that safety switch is missing, I can see the connector in the first photo in the bottom right I think. From that connector there is an 18" piece that runs down to the switch.

As far as the brake light switch goes, I have to lay on my back and get really twisted up to even get a glimpse of mine...

mckenziemc · 04-02-2009, 09:27 AM

It is different on 74 and most 75 CJ's Unless his jeep has a GM steeringAcollum. In 76 AMC switched to a GM steering collum. So our (pre 76)brake lights go from the switch on the pedal set to the turnsignal switch which is a bolton/aftermarket made by spartan which combines and powers the brake lights and turn signals then from the turn signal switch the wires run to the tail/brake lights.