Ok they other day I was out and about. When I would come to a stop the "Check Rear Lights"
came on. Not every time but more times than not. I checked to see and it appeared the tail/
brakes lights were working. Fast forward to yesterday I go out to the car and turn the key, nothing.
No click or anything. I checked voltage of the battery and was 12.87, Put it on my charger for a while
then moved to the starting position and still nothing. I tried to shift the car into neutral, but it will not
shift out of park. I also noticed while pushing on the brake there were no lights. Key on or not. The
battery is a year old and we drive it a couple times a week. So my question is saying the battery is not
the issue does it sound possible that it could be the brake light switch? Is there any way to check this?
Any help greatly appreciated. I searched and couldn't find a definitive answer.
Larney

 

I get intermittent amber light and warning "check rear lights" when I apply the brakes on my 2001 XJR. But I have never had an issue with starting like you describe. I haven't dug into it yet, but it has absolutely not affected my car's usability at all.

Even if the brake switch was failed I can't imagine why it would basically kill power to the car, which is what I think you're describing. I would check all of your main power items, start with remove, clean and reinstall both batery cables and the main relays which I think are forward of the battery in the battery compartment.

 

Check the power stud on the 'False-Bulkhead' and look for overheating and/or loose connection.
That is the B+ to the Starter and Alt.

Check the earth connections to the lamp bulb holders.
Look for 'burnt' terminals in the connector area.

 

Pardon my stupidity, where would the "false" bulkhead be?
I was leaning toward brake light switch since there are no brake
lights when depressed, and it won't shift out of park.

 

The brake light switch is cheap and would probably be the first thing I would check.
I know that other members have had the shifter locked by a faulty brake switch.

 

Sorry, I thought you were having a NO START issue.(read it wrong)

 

No I have both. No start and can't shift out of park. Also no brake lights.
HOWEVER I just went outside to make sure all my rear lights/turn signals
worked. It started right up. Damn... I will back track a little. The day the warning
lights were coming on it was raining pretty heavy and I was out in it. So now I
wonder if maybe something got wet and just needed to dry out for a few days(
78 here yesterday and about the same today). Great won't this be fun to track and fix.
Maybe it's just a sunny day car. lol.
Larney

 

Did you check the battery power stud on the right 'false bulkhead'?
Just aft of the RH damper/spring tower there is a fiber 'bulkhead' with a copper stud for power transfer to the starter/alternator. (LARGE WIRES)