Datsun Roadster Forum-311s.org

Hey everyone!

Excited to be here. My name is John and I am 27 years old, just starting to get into cars. Well I have always been interested in cars but never had one of my own to work on...but now I do.

My father and I have recently started to fix up his 1968 Roadster 1600. The car is running beautifully but we can not get the rear brake lights to work. Our mechanic informed us that the Rear Chasis Wiring Harness would need to be replaced. We, nor the mechanic, can seem to find this part anywhere! We would love to get the car inspected so we could get it on the road ASAP. Any and all help on this issue would be greatly appreciated.

Thanks everyone!

Welcome,

Post some pics of your project. We have a fellow on board whom makes new harnesses. Curtis is the man and if isn't too busy I am sure he will be glad to help.

Steve

Try Curtis Marsten: cvmarsten@w-link.net

www.datsunparts.com

Thanks for the guidance! I added some photos of the car.

Do all the other lights work: headlights, front & rear turn signals, front parking lights, rear tail lights?

They did get all of the front lights running, but there was previous repair done to both the lh/rh rear brake light pigtails. They found some of the plugs unplugged and then they found out why, with the plugs plugged in the brake lights stay on consistently. They did look at them and got some of the issues to work, but the brake lights still are staying on and they suggest replacing the rear wiring harness that runs back to the rear lights. The turn singles and radio all work well.

Could just be the brake light switch. Worth a check. Cheaper than a harness.

S

Sounds more like a brake light switch, as Steve mentioned. It's connected to the brake pedal arm.

S Allen wrote: Thu Jun 16, 2022 2:47 pm Could just be the brake light switch. Worth a check. Cheaper than a harness.

S

GeoffM wrote: Fri Jun 17, 2022 12:44 pm Sounds more like a brake light switch, as Steve mentioned. It's connected to the brake pedal arm.

x3. It's possible the previous pigtail repairs weren't done properly, and I would like to think the electrician/mechanic checked the brake switch, but you should still double-check that first.

If the electrician/mechanic is unfamiliar with roadsters, they would look at the brake line junction block and the elec connection on it and think that brake lites are controlled by brake line pressure. (like many are)
But, the is the S-brake switch (I think) and they are controlled by a physical switch mounted vertical on the pedal arm, with a rubber disk which actuates the plunger switch. If the rubber disk wears out or falls off, both brake lites stop functioning.

If your mechanic can’t fix something as simple as the brake lights on a roadster then it might be time to look for a new mechanic

True, though the "constant hot - switched ground" on the headlights on later cars has confounded me to no end.
Since blinkers and rear brake lights all go thru the blinker switch (correct?) it is always a good idea to give it a good cleaning. (same with Emergency flasher switch)

FergO2k wrote: Tue Jun 21, 2022 8:06 am True, though the "constant hot - switched ground" on the headlights on later cars has confounded me to no end.
Since blinkers and rear brake lights all go thru the blinker switch (correct?) it is always a good idea to give it a good cleaning. (same with Emergency flasher switch)

The ground Neg is the hot ...or both are
DC current flows from neg to positive, is pulled into the pos batt terminal

I recently had a similar issue. Mine was the Brake lights would not turn on. I replaced the Brake switch and it fixed it. maybe try it because it's cheaper than a new wiring harness

Hey everyone - thank you all for the feedback. The mechanic said he did in fact replace the switch with a universal switch. Should I try an original Datsun switch? Or do you not think this would make a difference?