Won't crank, won't start puzzler.

My first post here, help much appreciated. Been learning to be a DIY mechanic by working on my 2001 4Runner but I'm stumped and the dealer is the next stop...

4Runner was working fine. Arrived at in-laws, stayed 15 minutes. Turned the key, nothing happens. No clicks, no crank. But lights and accessories turn on.

Battery is not the issue (tested good with multimeter, trickle-charged it to be sure, tried jumping it twice as well.) Fuses don’t seem to be the issue, I tested all bladed fuses with a continuity tester.

Starter is not the problem. I removed the starter relay and “jumped” it by connecting ports 5 & 3 using a jump wire. The starter cranked – but the engine did not start. Tested the starter relay itself and it is fine as well.

I replaced the neutral safety switch. Nothing changed. Still not cranking when I turn the key.

I’m guessing it’s something in the ignition system – something that prevents electricity going to the starter relay (hence the jump wire working, which bypasses the ignition circuit) and simultaneously prevents fuel or spark at the engine (hence the engine not starting despite getting the starter motor cranking by using the jump wire at the starter relay ports.)

Any clues much appreciated!

2001 SR5 4Runner, 4WD A/T with 3.4L V6

 

I do not know the particulars of 4runner relays in the start system. But, I would start my trouble shooting there.

 

Aftermarket alarm system?

 

No aftermarket alarm, but there is a stock Toyota alarm. Thought this just made noise, can't find evidence that it locks up the starting sequence but would love it if someone knows more...

 

Just tossing out two thoughts…foot on brake is one (bad brake pedal switch?) the other is maybe the neutral start switch went bad?

 

I had a rodent chew through wires and it did exactly what you are describing. Toyota does use soy based wire covering, so they love it. Had to have it towed to be repaired. I hope that is not the case. It was not cheap.

 

Brake lights activate when I press the brake... should mean the brake switch is good?

I changed the neutral safety switch, was thinking that too.

 

A damaged wire somewhere seems reasonably likely. It just was driving 15 minutes prior to it not working, so I imagine it would be isolated to a single wire somewhere, not like rodents ate a whole harness worth...

 

Anyone know if there are any other relays in the start system? I tested the starter relay, under the hood.

 

My 2004 Pilot a couple years ago had a Main Relay start intermittent working, Pilot start system went dead. $50 part but deep in dash so lots of labor.

I do not know about our 4runners?

 

Looks like the security system is the RS3200 Plus. It is capable of disabling the starter, could be a lead. But when I disarm the alarm using the key or fob, nothing changes. Wondering about removing the alarm system but this doesn't seem easy.

 

Since your runner is a 2001, that is lots of corrosion opportunity exposure.
I had a Volvo that had an internally corroded red cable to the starter. It passed voltage fine with multimeter, but would not pass enough current (amps) to start the car.
It looked fine, just oxidized red insulation and minor corrosion at junction to swaged terminal.
Replaced it and solved the problem.
Are your cables original?