Intermittent Issues When Starting / Electrical Gremlin?

[Stack Up]

2013 Land Cruiser w/ 150K miles. No modifications or changes in the last 2 years, but vehicle has dual battery set up, aux lights, winch, etc.

Have a strange issue that started 2 months ago. Truck unlocks with key fob, get in, press brake, push the start button, everything lights up, A/C comes on, but the truck doesn't try to start, and then everything goes dead a second later like the battery has been disconnected.

Wait a few minutes and the lights will come back on, stereo resets, A/C comes on, etc. This part has happened with me still in the truck and outside the truck looking under the hood. Try to start again and it will start. The trip odometer and radio are reset like the battery has been disconnected. This has happened 3 times in the last 2 months.

Today this happened, but it went through try to start, everything comes on, electrical disconnect, get out look under the hood, everything comes back on, get in, and try to start 3 times with no luck. Came inside to let work know I would be home today. Changed clothes. Went back out and it started right up. Figured the only difference was the location of the key fob in my pocket.

Turned it off, put the key fob in my hand behind my back in the seat. Tried to start and electrical disconnect again. It reset while I was still in the truck. Tried to start again and it started right up.

3 months ago the alarm started randomly going off. I changed the battery in the key fob and I haven't heard it since. The other active issue is a TPMS system alarm has come on and the truck is no longer reading tire pressure. Not sure that its related.

Anybody heard of random electrical disconnects when trying to start on a 200 series?

 

[Leaky2014]

I’d start at the battery terminals.

 

[tbisaacs]

This, and pull the kick panel and make sure you don't have any signs of water intrusion.

 

[T4Runner]

Been having this type of issue for several weeks. It always eventually starts; however, last week it would not start. Hooked up the NOCO GB150 and it was showing battery ok, but wouldn’t start. Dash would go blank when I put foot on brake pedal. Swapped jumper from negative terminal to chassis ground and started right up. Let it idle for a bit then borrowed a car to go to work. After work, I disconnected battery and cleaned the battery terminals and connectors thoroughly. Tightened everything up nice. Started every time, multiple times a day, from last Tues evening for remainder of last week and all through this week until Sat night. Pushed the start button dash lit up, but was not trying to start. After giving the LC time to collect itself it started up and I drove home. Haven’t tried it today. Every time this happens the ScanGauge goes wonky and I have to disconnect it and plug it back in so I’m not getting any codes. Not sure what else to do. Appreciate any insight and/or suggestions. [Edit: 2014, 143K, Battery:
X2 POWER PREMIUM AGM BCI GROUP 31T (installed 12/24).]

 

[bloc]

Been having this type of issue for several weeks. It always eventually starts; however, last week it would not start. Hooked up the NOCO GB150 and it was showing battery ok, but wouldn’t start. Dash would go blank when I put foot on brake pedal. Swapped jumper from negative terminal to chassis ground and started right up. Let it idle for a bit then borrowed a car to go to work. After work, I disconnected battery and cleaned the battery terminals and connectors thoroughly. Tightened everything up nice. Started every time, multiple times a day, from last Tues evening for remainder of last week and all through this week until Sat night. Pushed the start button dash lit up, but was not trying to start. After giving the LC time to collect itself it started up and I drove home. Haven’t tried it today. Every time this happens the ScanGauge goes wonky and I have to disconnect it and plug it back in so I’m not getting any codes. Not sure what else to do. Appreciate any insight and/or suggestions. [Edit: 2014, 143K, Battery:
X2 POWER PREMIUM AGM BCI GROUP 31T (installed 12/24).]

Have you pulled the door sill trim and checked for water and/or corrosion in the large connectors there?

 

[T4Runner]

Have you pulled the door sill trim and checked for water and/or corrosion in the large connectors there?

I hadn’t really considered water ingress, but I will take a look.

 

[mark71]

Do you have the old Slee battery terminal connectors? Very prone to loosening and shorting.

I put dielectric grease on mine and keep them snugged up. It stopped that annoying behavior.