I searched the message board for solutions to my problem, but couldnt find anything specific to my situation and could use some guidance. My stop lamps/brake lights dont light up when I press the brake pedal. I have tried the following:

1. Replaced all the bulbs and checked the wiring to the bulbs.

2. Checked the engine compartment for frayed or disconnected wires and didnt see anything obvious.

3. Checked the fuse with a circuit tester and it is working (power running through it and lights on both sides of the fuse).

4. Bought a new brake light switch and tested to see if the switch was the cause and it wasnt (the brake lights didnt light up when the new switch was connected).

Am I missing anything obvious (such as a relay or another switch in the trunk area)? I noticed there was another switch the brake pedal activates next to the brake light switch. Should I test this one?

I also wanted to see if anyone would be willing to share a wiring diagram for my vehicle? Thanks. I appreciate any help.

Tom
Modified by tommyg at 10:54 PM 6/29/2009

Your FSM (factory service manual) is available in our library at http://www.nicoclub.com/FSM/

If I remember correctly the '97 one is incomplete, but the '98 version should be very similar and help you out with this.

The other brake pedal switch is is for the cruise control. Other than that I don't have a lot of specific knowledge about the later Q45s.

Good luck!

Heath

Many thanks! After looking at the diagram it looks like it could possibly be the Stop and Tail Lamp Sensor, but I am having trouble finding the part. Can anyone tell me where it is located on the car and what the part number is? If anyone has a picture that would also be helpful. Thanks again.

According to your FSM it's in about the same place as the 90-96 Q45's. Look under the trunk trim below the trunk lock. It's adjacent to the trunk lock actuator. See page EL-422 of the 98 FSM.

I was able to repair mine by resoldering a couple of burnt solder joints. Follow the path of the pins, especially the ground, and see if there's evidence of solder melting or burning. They're about $90 new so it's worth the effort to try and repair the sensor.

http://www.nicoclub.com/FSM/Q4...l.pdf

Thanks. Opened up the Stop and Tail Light Sensor today and didnt see anything burnt out or damaged. Also, checked the connection with a circuit tester with the brake pedal down and didnt show any power.

Is it possible it could be a joint connector? Do those usually go bad? Also, what is the color of the wire I should test further up the line (sorry, this is my first time at this)? Thanks again for your help.

Tom

Modified by tommyg at 5:56 AM 7/1/2009
Modified by tommyg at 5:57 AM 7/1/2009

I'm helping a friend diagnose the same problem in a 1992 Q45 and found this thread in the archives. I was hoping the original poster or someone else may be able to offer some info if a solution was found!

In my friend's car, the center brake light will come on but the left and right tail brake lights don't come on (tail running lights are okay). Since the middle light activates, I'm assuming the switch should be okay? He told me all fuses are fine and all bulbs are new. My guess is to look wherever the signal splits to the 3 different lights but since I'm not familiar with Infinities, I don't know where that would be.

Thanks for any help! We're hoping to get this sorted out ASAP so he can make the drive from OH to visit me in MA in a couple weekends but that won't happen if he doesn't have brake lights!
Modified by zuren at 9:48 AM 3/18/2010

The CHMSL working, with the two main ones not is a telltale sign of a bad sensor. Check it for melting, etc... You may be able to resolder if it's not too far gone. If you have a pull-a-part style junk yard nearby, I find that these are almost never gone. Make sure you get the same type. 90-93 use a pink one, while the 94-96 uses a black one - they changed due to the change in current draw. 94-96 use only one bulb per side vs. 2 on the older ones.

Good luck!

Heath

Thanks for the reply Heath! You wouldn't happen to know the part number of that sensor would you?

I looked at the FSM link and see where it should be located (near the trunk latch - assuming that the "Stop and Tail Light Sensor" is in a similar spot as on a '98 Q45). I have tried searching online parts stores for that sensor and I'm not pulling up much.

Thank you again for the help!

Yes, it's in the same location. Remove the plastic finisher between the bumper and trunk compartment, and the trim below it.

The part number and pricing information from Infiniti of Scottsdale:Item Number 28425-60U00 MSRP $131.22 Price $98.41

Expensive little bugger! I would look in our classifieds forum for people parting out a 90-93 Q45, or if you can find a pull-a-part style junk yard it's probably still there. I rarely see them missing.

Good luck!

Heath

Thanks for the information!

Please correct me if I'm wrong, but we assumed that all this sensor does is feed information to the readout on the console so my friend bye-passed the sensor. The brake lights work again but the console reads "Tail Lights Inoperable" which he can live with. We'll look into getting a new unit but for the time being everything seems to be working.

Thanks again!