Erich Stein

1995 4runner 3vze 3.0l

Hello. I upgraded my alternator to a 1-wire marine-grade, 6 months ago. Run that for 6 months no problem. 2 nights ago, truck left me stranded would not start. The old wire lead to the alternator rubbed insulation off and arc'ed against the alternator. This caused a short. The 80-amp fusable link to burn out. I replaced the 80-amp fusable link inside the fuse-box under the hood. I also ran a brand new 8-gauge wire to the alternator, bypassing the old wire entirely.

I test every fuse GOOD for continuity: Each one in driver-side fuse box on the floor, and the fuse-box under the hood.

---- Now my trouble gets more complicated ----

Truck will NOT start. 2 issues:

1) Key in the ignition, the LOCK toggling shifter out of park will not release. I have to insert a shiv inside the shifter to bypass.
*) I can not seem to find the pages in the FSM that explain how this shift-lock works, how to troubleshoot. If they exist, they appear to be hiding from me.

2) Key to "START": The relay in the fuse-box under the hood will NOT toggle. I removed the blue relay, tested +12v manually using direct 12.5v battery voltage and tests GOOD. I re-insert blue relay, and NO-GO.
*) I test 12.5v on battery. Only 11.6v on the lead for the relay socket when I test turn ignition key to "START".
*) A manual bypass wire from 12.5v battery -to- the relay terminal in the fuse-box WILL toggle the truck to start.

3) MY Factory FSM appears to be missing the details on how I would remove the ignition combo switch from the back of the lock-strike. I do not want to mess that up, ideally would like to remove it to clean and reinstall to proceed with caution if necessary. I am unsure if this is my problem.

I am suspecting the electricity that travels from the fusable-link into the ignition switch and everything between has been compromised somehow. Possibly a weak terminal connection.

---
Can anyone advise please help ?

scope103

Are you sure you have power to the underhood fuse panel? A short of the alternator lead could have taken out the fusible link wire as well as the plug-in 80amp. (The main lead to the starter doesn't go through the fusible link, so if you run 12v directly to the starter relay coil, then the starter will spin.

Assuming you have power to the relay panel, then it does sound like a high-resistance in the ignition switch (this is the "gotcha" of digital multimeters. They pull so little current, they can pick up a voltage through a very high resistance. If you use a test light I'll bet it won't light; it will pull enough current through the high resistance to drop the voltage.)

Here's the FSM for the ignition switch. http://web.archive.org/web/201102052.../3ignition.pdf Pin 3 is power-in (AM1), pin 6 is power out to the starter relay. I would try to back-probe that connector, checking for voltage to ground. I'm guessing you'll find very little voltage on 6 with the key to start (and the connector plugged in, so the starter relay is trying to pull current.)

Erich Stein

I am definitely getting power into the ignition switch. Dash board lights up, radio, etc...

The START turn on the key WILL deliver 11.6v to the terminal where the start-relay sits in the fuse-box under the hood. It's apparently not enough voltage to trigger the relay. Like the wire, terminals in-between have corrosion or resistance, I am uncertain.

I can manually override, take a hot 12v wire in the terminal where the relay sits and it will turn the truck over.

I will re-check the continuity on the terminals in the steering column, again.

I do not know if / how the shifter unlock and the start relay voltage are related.

scope103

Remember, "deliver" 11.6v into no-load is very different from trying to deliver it (through a very-high resistance contact) to a load. Even one as small as a relay. You could try a test light (very roughly equivalent to the load of a relay), and to double up you could test the voltage with the test light as a load.

The shift lock is not powered through the ST1 contact, but here you go: http://web.archive.org/web/201008061...2/shiftloc.pdf

Co_94_PU

iTrader: (-1)

Voltage alone does not equal power power (Watts) is volts time amps, volts and amp are power..

You need to inspect the fusible link wire between the battery and junction block (your under hood fuse panel), it's likely partly burnt or loose on either end. You'll find it screwed/bolted to the bottom near where the 80amp one you replaced..
...
You shift lock and starter relayvarent gettingvthe power they require..