Lexus Troubleshooting Questions? Ask a Lexus Expert
Do you have a code reader? When you turn the key to the start position do the head lights dim if they are turned on? Is any work and onto a recently or do you have any recent service history on the car leading up to this current problem? At any time was the vehicle jump backwards when the battery was replaced or prior to it? Does everything else in the vehicle appear to work normally electrically?
When you turn the key to the on position do all the normal warning lights including the check engine light illuminate? When you install the upper intake manifold did you make sure you got both of the ground wires on the back of the intake manifold clean and tight they are 10 mm bolts? If you turn the key to the on position and take a jumper wire from the positive battery terminal go to the small terminal on the starter can you make the starter engage and will the engine started run? I have to step away from my computer I would back on this evening with some follow-up information if you need more.