Hey,

1998 4Runner Sr5, 5 speed.

Moved from California to New Jersey this year and I had some issues pop up this winter I can't figure out. They only happened when it was very cold 'till this morning when we had some very serious rain with warmer temps. The pass sunroof drain disconnected at some point but I fixed that a couple of months ago.
I will start the truck, idle is high, ft passenger opens on own, abs light and batt light are on going from dim to ultra-bright and front speakers stop working. WTF!?!?

This car has extensive mods including remote start alarm with windw module, aftermarket radio with amp for ft speakers and sub, painless aux fuse block, heated seats, supercharger with urd electronics and 7th injector and cs144 alternator. But this was all installed for many years.

I can't find anything similar on the internet have no idea where to begin troubleshooting this. What do the front window, abs, stereo (amp) and batt light have in common??
No codes found and when it was cold this would all go back to normal after restarting when the car warmed up.

Please help!

Matthew

 

When you say window module do you mean a module for the alarm or one to control the power windows?
I'd disconnect the remote start/alarm and temporarily put that wiring back to stock see if anything changed.

 

Inspect where sunroof drain may have leaked water.
Look at your FSM and see if circuits for mentioned systems are physically located near each other and inspect that area for water/debris/corrosion.

 

All of the above, and check your Alternator voltage, could be overcharging messing things up, I would pull the stereo and make sure there are no bare wires aswell.

 

Checked the alternator, 18.9 volts at idle...

 

Higher than usual. Pls double-check, AND inspect THE OTHER wire that goes from battery to altermator (feedback aka sense wire, thinner than Alt to battery wire). With engine off, that wire should read battery voltage; it tells the regulator the charge state of the battery. If regulator sees.low voltage it will keep on pumping out more voltage to recharge the battery, resulting to.over-charging, and subjecting components to over-voltage with unpredictable outcomes.

 

No need to double check,.. 18V at idle means your hitting 20V+ above 1500rpm, look no further you found your issue, My 99 Limited did similar things to me, 16V at idle and 18.5V at 2000RPM, lets just hope everything was protected enough, glad you checked.

 

Still need to find root cause to know what to fix/replace.
Bad wiring - no feedback to regulator?
Defective regulator, producing too high a voltage even with proper feedback?

 

It is the Alternator, you cannot easily change the regulator on these after 10-20 years of service, you replace the alternator, Only the Alternator can produce 18V regardless of wiring feedback, it is an internal regulator, Change that and see how it behaves, go from there.

 

Rad4runner wins the prize!!
Turns out the adapter plug I bought to go from stock to the cs144 was not weather sealed (and poorly made). There was definitely a ton of corrosion and maybe some arcing going on that caused the male pin of the sense wire to break of in the stock part of the harness.
I didn't have time to cut and solder but I am confident that this is my issue. Thank you sir for your input.

Side note, the firewall A/C drain hole is sealed with a piece of square foam? Maybe I lost a part over the years but not the brightest Idea Toyota. The sound deadening wool carpet surrounding the drain is soaked and moldy...

 

Hoping that's the only problem.
See how we lose nothing by inspecting our wiring but we lose when we buy and replace components (like alternator) without verifying, then realize the problem is still there because of bad wiring going to them?

Not so fast but I'll take a 4-pack of this