ccconor

I just bought a major project, 92 LS400 does not run, think it’s fuel pump related. Anyway. Today I was trying to figure out what was wrong, pulled the fuel pump fuse checked it, put it back in and got in the car. The dash lights would all stay on in the ACC and On postition but as soon as i turn it to start, i heard a click and all power was lost to the instrument cluster, radio and, pulled the main fuse out and put it back in. At first didn’t seem like it did anything, but then all of a sudden all the lights on the dash and the radio, back on, flick it to start again, heard the click again and all
power was out again. Anyone got a clue on what I could be dealing with here?

400fanboy

Did you check the battery?

ccconor

Yes, battery is fully charged and holding 12V

400fanboy

I just say that because you didn't mention. That's all.



Are we blowing fuses here? Does the car not turn back on until you reset the main fuse? Can you reset individual fuses instead to fix it to try and track down which is causing the whole party to trip offline?

To me this says some sort of electrical short or connection issue somewhere in the wiring. Beyond that... it's not ECU since that doesn't present problems like that. Starter motor wouldn't kill the whole car.

Could be as simple as a bad connection on one of the major leads.

Yamae

I'd rather think it's caused by the failing ignition switch.

ccconor

After a lot of checking on wires etc, I just think my leads weren't on well enough or my battery was done, even though it holds 12V. Put a different battery in from my other car, tightened it all up and all electrical works, put the Lexus' battery in the other car and it works. No clue what happened but it's all fixed now.

paulo57509

I suspect this is the culprit too.

My '98 has been doing the same thing intermittently for the past few months It acts like it's a weak battery or faulty cable connections; turning the key back and forth between OFF-ON a few times and then back to START will get the engine to crank (with authority).

Getting to the ignition switch is some what of a pain (in the back).

Yamae

Yes, it's not easy to access the ignition switch but it would be better to replace it before the problem becomes more serious. I know a man who had a similar problem with you. He finally lost the power when he was driving at a highway. The power steering and the brake assist were both lost and he was about to have an accident. It was late at night and the traffic was not busy and he was managed to be OK. After replacing the ignition switch, he no longer has the problem.

paulo57509

Always good advice. My outside to-do list is growing by the day but I'm waiting until it cools off a bit. It's been ~43C for the past week.