EricT

My wife drives a 99 RX300 with 69000 miles on it. No previous problems, but last night her head lights went out and had no dash lights either. She also said that when she went to start it, it didn't want to start. Possible bad battery? Bad switch? Any help is greatly appreciated.

salimshah

Start by twisting the terminals. They should not move/spin. The terminals should be devoid of any crud.

I would also suggest , getting the battery tested under load.

Salim

bob2200

Original battery (sight-hole on top that show blue when normal)? I know there has been some disagreement on this, but I say replace the 9-year-old battery, if original.

EricT

The only light that works is the interior dome light, no tail lights no nothing. And it also has it so that I shift the transmission from park. If you rev up the motor the check engine and something else lights up real dim and then as the rpms go down they disappear.

salimshah

After checking the terminals check the main fuse(s).

All sensors send an electrical signal and that is based on the battery ... with weak or missing battery (due to fuses) will generate an incorrect sensor output.

So start with the basics ... battery fuses etc.

Salim