1986 4Runner 22RE Auto

Alright so everything worked fine up until the ole 4runner took a dip in a hole a little too big for it getting water in the passenger side up to the glove box (truck was side ways in the hole so barely any water got into driver side) and now ive lost my dash lights.

started as the 15A TAIL fuse blowing everytime a new one was inserted.

Unplugged the dimmer switch and voila we have tail lights and clearance lights and the fuse stays conjugated but no dash lights obviously

If i plug in the dimmer switch and turn it all the way up the dash lights glow dimly for about 5 seconds then you hear the fuse pop.

ive unplugged the cig lighter, the radio, and alot of different other things on that circuit and it still does the same thing.

Am i dealing with a simple bad dimmer switch or is this something else shorting out and popping the fuse?

 

Please always indicate Model-Year-Engine-Transmission-Trim (put on signature to save everybody time), so we know which schematic to look at... Else we assume it' a Cadillac

 

oops sorry missing vehicle information is fixed now

 

Hmmmm.

Are you willing to tell us the problem, how you found it, and how you fixed it? We'd all like to know, even if (particularly if!) it's something embarrassing.

 

the problems not fixed i meant i fixed leaving out vehicle information lol

 

Any electrical guru’s? sucks driving not knowing what u running or if im bout to run out of gas lol

 

I doubt it's a bad dimmer switch. If it failed open, you'd have no lights, and if it failed closed, they'd just be full brightness.

The only things on the other side of that dimmer are lights (combination meter, heater switch, hazard switch, cigarette lighter, radio, ). So one of those tiny light bulbs is now shorted.

I don't want to be the bearer of bad news, but if you had water up to the glove box, your ECM, and every wire to the ECM, went swimming. This is not good ....

 

Yeah i took ECM out blowed it out dried it out and dialectric greased the connectors going to the ECM to try and keep corrosion at bay best i can. Truck runs good time will tell if corrosion will cause problems down the road. i guess i might just do an LED conversion for the dash lights and run it on its own circuit. radio and cig lighter and all runs fine

 

So you’ve got a short in wiring harness. Old wires have a tendency to crack over time especially if vinyl insulated. I had a similar issue. Turns out it was a trailer light adapter that PO had wired. I had cut plug out and taped up exposed wires. But up behind interior panel insulation was cracked and a little moisture and similar problem as your having.

Tracking down electrical gremlins are always a pain and no easy way to do it. But it can be done. Unplug and remove fuse and check do continuity to ground. Toyota used harnesses that connect to main harness so it’s a doable. Pick an end of the circuit and run it down.

 

Therefore Like pouring fuel on fire. Keep it simple. Take dash off, use senses before a multimeter. See, feel, inspect for shorts / debris/moisture causing a short.

Check your glove light wiring for short?

 

I can take the dash apart in the morning and check for anything funky going on in there but that would be odd to me since water only made it to the passenger side.

I thought about this when i was pulling things off to look for the short then i realized i dont have a glove box light or any wiring for one. no cut out next to latch.

on the dimmer switch connector i have a path to ground on both pins. they both ohm out at like 2 ohms dont know if that means anything.

 

Pls put me in your driver's seat.
How many pins does dimmer switch have?
Are u measuring connector wired to the dimmer OR connector wired to dash assembly? A picture paints a thousand words.
Just for fun, was water this deep?
https://youtu.be/8xurr79YW98

 

Dimmer connector has 2 pins. Red/black wire and tan/black wire. both have a path to ground. if im reading the wiring diagram right R/B wire should be 12V and the T/B the path to ground. Ohming out the R/B to a nearby ground i get right at 2 ohms of resistance. lol submarine landcruiser

 

Checked Light Reminder Relay, above ECU? That's why model-year-engine-transmission-TRIM matter.
R/B to T/B 2 ohms while completely disconnected?
T/B = actually white /black. White turned tan from age or heat?
You measure 2ohms from R/B to ground with rheostat disconnected?
If I can access it easily. I'll measure my rheostat, but 2 ohms sounds about right.
Disconnect everything from dash, measure Green Wire on connector R/B.





LOL! Yup. New, $90K trucks could not do that, and the new $30k-$50K 4Runners have less MPG than our 34-YO trucks.