Gauges Going Crazy

I have a 2002 L-Series. The change oil light came on not two weeks ago
(not changed yet) but today while picking up my son I turned on the
engine and the Security light, ABS, Service all came on and while
driving home (5 minute drive) the fuel gauge and Temp gauge kept going
down to Empty/Cold respectively then they'd bounce back up. While the
gauges were down the care would studder and all panal lights would
dim.

We have been having issues with a rough idle while stopped in gear or
not. Are these related?

 

Check your alternator or a lose or dirty connection.

 

As Paul Wrote, check that the battery and charging system are in good order
first. These cars seem do do strange things at low battery voltages.

AFIK the instrument cluster is driven by the BCM. Best to get the codes read
out first by a good shop and then decide what to tackle. Sounds like a loose
circuit but whether it's a power circuit or the CAN bus, can't say.

Bob
'01 lw300