Not starting - stumped by diagnostics - HELP!!!
Lexus Champion
Joined: Mar 2011
Posts: 2,186
Likes: 728
From: Texas
same symptoms as GARYC....I followed his steps hoping to find a blown fuse.
I have a 2002 LS430 that won't start. Symptoms and diagnostics are odd:
- New battery, freshly charged
- No clicking sounds
- Getting all dash lights etc. turning on like normal
- Oddly, the cooling fan comes on when ignition turned to "on" position
Here's the mystery:
> I pulled the starter relay and checked for voltage at the terminals. Have no voltage to the starter feed terminal, and also no voltage at the relay actuation terminal when the ignition is turned to "start".
> The 7.5 amp fuse feeding the actuation side is good, as is the 30 amp fuse feeding the high-current side to the starter.
> There is voltage at the 30A fuse, but the odd thing is that I get no continuity detected between the other fuse terminal and the receiving contact on the relay. According to the wiring diagrams I have been able to find there is no component between these two points, and both are on the same fuseblock.
This situation plus the fan running make me wonder if perhaps there was a voltage spike that fried parts of the wiring and/or cpu.
Also, if anyone has a diagram with which I can confirm I'm checking the right relay, that would be helpful. What I've found has been less than clear; it seems to be #18 in the attached diagram. I also attached the schematic I'm using.
I have a 2002 LS430 that won't start. Symptoms and diagnostics are odd:
- New battery, freshly charged
- No clicking sounds
- Getting all dash lights etc. turning on like normal
- Oddly, the cooling fan comes on when ignition turned to "on" position
Here's the mystery:
> I pulled the starter relay and checked for voltage at the terminals. Have no voltage to the starter feed terminal, and also no voltage at the relay actuation terminal when the ignition is turned to "start".
> The 7.5 amp fuse feeding the actuation side is good, as is the 30 amp fuse feeding the high-current side to the starter.
> There is voltage at the 30A fuse, but the odd thing is that I get no continuity detected between the other fuse terminal and the receiving contact on the relay. According to the wiring diagrams I have been able to find there is no component between these two points, and both are on the same fuseblock.
This situation plus the fan running make me wonder if perhaps there was a voltage spike that fried parts of the wiring and/or cpu.
Also, if anyone has a diagram with which I can confirm I'm checking the right relay, that would be helpful. What I've found has been less than clear; it seems to be #18 in the attached diagram. I also attached the schematic I'm using.
Driver School Candidate
Joined: Sep 2020
Posts: 2
Likes: 0
From: Michigan
Instructor
Joined: Jan 2018
Posts: 958
Likes: 299
From: WA
^ a click but no crank can be a sign of either a battery that needs charging and.or corrosion at the battery terminals. Check and clean the terminals, recharge the battery overnight, and see if it starts.
Advanced
Joined: May 2001
Posts: 650
Likes: 7
Same issue
Advanced
Joined: May 2001
Posts: 650
Likes: 7
I just cannot find responses on here on people fixing their issues . This must be common on high mileage LS430s . Same exact issue and diagnoses . One fix said his ground on the hell housing was had , so I ran my jumper from my battery ground to the hell housing bolt and still no crank .
Racer
Joined: Mar 2004
Posts: 1,402
Likes: 117
From: Colorado
6th Gear
Joined: Nov 2024
Posts: 6
Likes: 0
im having these same issues. Started happening after replacing my starter. My car hasn’t started since. I’ve gone bac and checked if it was connected , replaced my cracked gasket, bought a new battery, bought a new fuel pump, cam and crankshaft sensors. Some of the wiring to the sensors I had to Mickey Mouse but I think the connection should be good enough.
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