2004 xjr 115k miles

Beginning with the park brake warning, my radio display goes on and off and sometimes keeps playing,. Warning lights include transmission, fault, park brake + ongoing suspension fault. Sometime momentary loss of power
and tranny in limp mode. Usually a restart fixes but sometime after turning off, trying to start by twisting key results in silence. I had the front bumper ground inspected and cleaned. Any thoughts?

 

Load test your battery. Also, how old is the battery?

Also check standing voltage 10 mins after shutdown. Anything under 12.6V is no bueno...

 

Thanks, first thing I checked. The battery is fresh and voltage is perfect.
This begian after brakes and rotors - wonder if a brake sensor could cause this - e brake warning light frost to display.
sometimes no warning lights just radio freak out
or wiper

it's a freak show

 

Download the Electrical guide from this forum.

It shows positions of earths (grounds) which could be the problem.

How do the wipers behave?

If they come on for no reason suggest double check earths behind h'light.

 

the wipers participate on occasion, thanks, i'll re check grounds + electrical guide. best

 

UPDAte and many thanks for the responses and clues. After cleaning and checking the front grounds and checking the battery condition the condition persisted culminating in it dying while driving.
It just clicked when I tried to start it and there was a lonely wiper cycle. It would not go into neutral, so i could not get her off the road to safe place. i popped the trunk and inspected the battery and noticed that them pos. cable was
sure hot. I gave the battery a swat in frustration and the car started and I was able to get tp safety where i checked o see if the battery was also ht - it was not but there it was - staring me in the face - the batter ground (not neg. cable) was solos i could end tighten it. I did a proper job f that and no symptom for the last week. Enough to get encouraged. nNow if I get my arms around the suspension fault light thats been randomly on and off for 18 months...............