Nissan 720 brake lights

[jamesh]

Hi all,

 

I’ve glanced around at various posts related to this but can’t seem to figure it out, it’s raining here today so I can’t do much at this moment, but plan to get to it afterward.

 

the switch checks out OK. I just tested continuity with and without depressing the little button.

 

i was getting bizarre voltage readings at the switch terminals, less than 12v but fluctuating quite a bit from 4-9v.

 

i was curious as to how all of this is wired up. The white wire from the fusible link, tied to the pos terminal runs to the upper part of the fuse panel (inside, drivers side)and seems to power several things, one of which includes “stop lamps” - which has the yellow/red wire in that position.

 

maybe I’m asking an electrical 101 question, but where does this yellow/red wire go from here?  I think my manual shows it going straight to the brake switch. Could I run a new wire from fuse panel to brake switch? Anyone else run into something like this before?

 

It seems like the problem is likely as this wire is on its way to the switch. Since the yellow/blue gets its voltage after the switch, I assume all downstream wiring is OK. 

 

 

[datzenmike]

Might be better if you also describe what the problem is. What's it doing or not doing?

 

White from fusible link to fuse 8 through 13. Fuse 12 is 15 amp, Yellow/Red out to stop lamp switch, Yellow/Blue out to 10 pin connector under passenger seat, becomes Yellow/Red out through floor along frame harness to round 6 pin connector at tail light harness, to both brake lights.

[jamesh]

Sorry, no brake lights! 

All other lights, turn signals, etc completely fine.

[datzenmike]

 

 

Do the 4 way flashers work??? they are also on same fuse. Fuse 12 or 3rd one in from the far right side. Swap the 15 amp fuse with another beside it, see if it acts any different.

[jamesh]

Ok, so I started the truck and turned on the four-way switch. I noticed that from the inside only one of the turn signal flashers was flicking on and off, so I straightened out the wheel and gave it a light tap and both turn signal flashers were blinking on and off. Shimmed the brake pedal and voila, the lights are back.

 

what gives? Does the signal go to the steering column before going to the brake switch?

[datzenmike]

The 4 way flasher and the brake light only share the same fuse. By turning on the 4 way flasher you are only proving that the common fuse is OK. There is no connection between them other than they get power from the same fuse.

 

The brake light switch is normally open. It closes contact when the pedal is used. The switch  has a lock nut and screws in or out. Adjust so that the lights are out when the pedal is up. I don't know what you shimmed.

[jamesh]

Used a 4x4 to shim the brake pedal to the floor (actuating the switch) so that I could walk to the rear of the vehicle and see what was going on...