SerasLibre

Ran into some bad storms on my way home from work last Tuesday. Ended up driving through ~1 ft of standing water (very slowly!!). Everything smelled fine afterwards - I used the car Wed-Fri without issue. On Sunday I go to start the car and it doesn't crank. I replaced the battery (terminals are spotless - no corrosion) and get the same result. The starter solenoid engages but the starter motor doesn't turn. I know the alternator is low on the engine, and the starter is on top between the vee, so I am suspecting the alternator is toast. However, will a failed alternator prevent the engine from turning over, even with a fully charged battery?

Does anyone have any experience with failed alternators on these cars and whether they will cause such symptoms? I would like to try to jumper the starter leads but it they don't seem to be easy to access.

Any troubleshooting tips?

Note this is on a 2004 LS with ~125k mi. I have owned since 40k mi.

rkw77080

Sounds like you need to rebuild the starter solenoid switch. Check out the Youtube video below...

NL5

A bad alternator will not stop it from turning over.

SerasLibre

Any way to verify without having to remove anything first? The starter on the LS is no simple task.

rkw77080

As shown on the Youtube video, if you keep turning the key on and off, eventually the solenoid switch will engage and start the vehicle. You may have to repeat 20 times before this happens. This will prove that you have enough juice to turn the engine but the bad contact in the solenoid switch prevents the starter motor to engage.

911LE

Keep bumping the key and it will eventually start. If the starter was accessible you could tap on it with a hammer to get it to work. I would replace the starter asap as it's possible for the contacts to stick together when they are in this condition and the starter will continue to run, even with the engine running, until the battery is disconnected. Pulling the intake manifold to get to the starter isn't too difficult if you have some diy experience.

SerasLibre

So I finally got around to replacing the starter.

First of all let me be very clear is saying that this is the most annoying bit of wrenching I've ever done in my life! Getting access to the starter on the LS430 is extremely annoying, frustrating, and painful to your back and legs. Be warned they will be sore for a few days while you are working on it. I have a total of 8-10 hours of work into this repair. I had to clear a rats nest, scrubbed the V-bank clean, replaced some cracked/deteriorated wire loom, and cleaned the throttle body while I was in there.

After I pulled the starter I opened the contacts and it was clear that the starter contacts were wet from driving through deep water. Yesterday afternoon I noticed that my passenger side floor and carpeting was wet - from the storm almost a month ago!

Moral of the story kids: If you must drive through deep water, go VERY SLOW (no wake) and go on a very long road trip afterwards to heat up the engine enough to hopefully dry out the starter and prevent a royal pain of a repair job! I only did the former and had to suffer through not doing the latter.

MODs: Please edit title of this post to read :Solved.

NL5

Glad to hear that you got it figured out.