I’ve got a 1993 Ls400 that’s having problems not turning over at all, when it started I could start it and drive it as much as I wanted but when I’d shut I’d have to wait about 30 minutes to start it again or it wouldn’t crank at all. Not it won’t at all. All of the lights on the dash come on but it doesn’t crank. I’ve replaced the starter now but it wasn’t the issue, I have been able to get it to turn over by jumping the starter relay, I was thinking it might be the ignition switch but I’m not sure. I’ve also replaced the starter relay as well.

 

Kinda sounds like intermittent starting to me, I’ve had that problem but I had to wait hours lol. Try checking the timing belt

 

Did you load test the battery? that happened with my 96, dash lights still worked but the battery was at 10.6 volts and wouldn't crank

 

I put a new battery in it a few months ago after the problem started, made sure it was charged and everything, didn’t change anything

 

That sounds like the failing neutral safety switch. For the confirmation, try shifting the AT lever all the way from P to 1 to P a few or more times. Also try at N position.

 

I’ve tried starting it in neutral a few times but I’ll try that as well, I’ve also tried the theft system with locking and unlocking the doors but would that also kill the fuel pump? When I had the starter out I checked the wires and the signal wire had no power when attempting to start it. If there isn’t a fuel pump cut off I was thinking of wiring in a push start till I could properly fix the issue.

 

So you've already tried it in neutral. If shifting the AT lever does not help, you need to check the continuity of pin #5 and #6 of the NSS.

 

Any info on the location of the new? I’m having trouble finding it

 

https://www.rockauto.com/en/partsear...um=84540-30270

 

So I’m getting 0.0 on continuity from the neutral safety switch so I don’t believe that Is the issue
I also tried starting it by jumping the starter relay, it would turn over but wasn’t starting, like the fuel pump wasn’t engaging.

 

In that case, I'd check the continuity between the ignition switch to the NSS. Your words "I also tried starting it by jumping the starter relay, it would turn over but wasn’t starting," mean that the wire color BLKWHT line is not hot and the engine control line is not active. It is natural that the engine doesn't start without supplying the DV12V to the engine control line.

I worry that the ignition switch of ST2 contact or the ST fuse 7.5A or J/B4 is not conductive. I'd observe the voltage of the line BLK/WHT indicated by a red arrow below. Jugging from your symptom, the highest possibility would be the ignition switch of ST2 contact not passing through the current enough.

 

Is there a chance that my ignition switch has gone bad and that is the issue? I don’t know how to test the switch to see if it’s bad.

 

Put a test light on 1 if you get good power then go to test point 2. If those are good then work your way back in the circuit until you find the fault.

 

I believe point 2 is the signal wire for the starter, I know that I have no power there when attempting to start the car

 

That's a good data point now move back in the circuit to the starter relay. Maybe the starter relay died it happens.