bad ground somewhere on a 97

Just bought my 2nd xj and the oil pressure fluctuates when coming to a stop. initially I thought it was a bad switch, but now I noticed the temperature gauge is doing the same thing. It's a 97 year. I was wondering If anyone knew a ground strap that I can find that may be causing this? Also the backlights for the gauges are burnt out on each side.

only grounbd strap i know of is from the back of the head to the firewall.

i would check to make sure that there is a good connection at the back of the gauge cluster.

have you ruled out a bad oil pressure sending unit.