Brake Lights

Nick, the first area I would look at is the plug where the tail light wires connect to the center body.  The first question is if the plug is connected. The second thing to check is to make sure that all of the male and female metal connections are in place.  It is fairly common for these  metal connections to break off.  The likely culprit is the #3 female pin connector.  If this is the problem, new individual pins or receptacles can be orders and replaced.  

If this isn't the issue, I would do a power check at the chassis plug to see if you are getting power to female pin #3.  If you are getting power there, you should check the rear harness.  If you are not getting power there, I believe their is a mechanical switch near the brake pedal that could be out of alignment or could have failed.  I don't have a good picture of that area.

Charley

You can see in this picture what it looks like when one of the female receptacles is missing (in position #5)

Charley,

Thank you for the fast response! I am checking power at the chassis plug (and thanks to the wiring diagram provided under the resource library) I am not getting any power to pin 3. The pins appear to be in good shape. The thing I am confused about is the location of the brake light switch? I am looking near the pedal box area/FR/RR masters and cannot find a mechanical brake light switch????

Thanks,

Nic H

Charley,

Quick update, I was able to find the hydraulic brake light switch in front of the LR wheel and I think with the help of my dad pressing the pedal we were able to determine the switch is bad. I attached a picture for future reference for people to know where the brake light switch is (it might be different for different yrs/cars). My finger is pointing to the switch.

Thank you,

Nic H

Thanks for the update Nic.   I am glad to hear that you got it sorted out.  I should have remembered about the switch being there.  I have been working on a Prosport lately so I guess I was thinking about that.  Here is a diagram that shows where that switch is.  It is too late to help you, but perhaps others will benefit from it. 🙂

Charley

Thanks for sharing this post, it really helped me identify the issue with my own brake lights today!

I've attached a closer image of the hydraulic brake light switch, which others may find helpful.

Cheers,
Tom

I’m not sure if it’s because my bias is set to far to the front and this switch is on the back but I have to push fairly hard on the brakes to activate the brake lights. 

I had that switch go bad multiple times on SR3's... When brake lights don't work it's the first item I look at these days... Sorry I did not see the thread earlier to help on locating it.

Regarding pressure, it should come on quite early when pressing brake pedal (I'd imagine 5 bar or less) which is really not much of a pressure on the pedal... First thing I would recommend is to bleed the rear brake circuit, if you have air in there, pressure could build less quickly than front causing the switch to close later. Next thing, once you've bled both front and read, if you have brake pressure sensors fitted, I'd check the pressures and correct balance to set it as per factory dry recommendation (55% Front bias) then see if the switch works better. If still no joy then I'd replace the switch. 🙂