ITO

2006 Double Cab Tundra
Not working:
Radio
Blinkers (hazards do work)
Power windows
AC
Charging

The problem first manifested itself by draining the battery when the car was turned off and sometimes the truck would try to start itself without the key in the ignition. Typically this would happen when the alarm was on and it was raining.

I replaced the following items:
Alarm system with a Viper.
The battery (it was old), and the problem persisted.I replaced the ECU

The truck stopped trying to start itself late a night, but then the dash lights, windows, radio, blinkers, and AC stopped working.

So I took it to a mechanic and after two weeks and $900 he said he could not find the problem but after trouble shooting all the relays, fuses, and joints it all started working again. He also said he suspected it was something in the fuse box or one of the connections to the FB.
The truck ran fine for about a month then after a really big rain, the following items stopped working.

Radio
Blinkers (hazards do work)
Power windows
AC
Charging

I replaced Alternator (it was a shot in the dark but I wanted to eliminate it as suspect).

I then checked all the fuses, joints and relays too and everything started working. However, when I put it in drive the same stuff stopped working.

After reading about the ground points being suspect, I got a drawing of the all the ground point locations, found all but one (the one under the carriage labeled BS). I took each one apart, cleaned it with a wire brush, removed the paint and put them back together.

Now I am right back to the following items not working:

Radio
Blinkers (hazards do work)
Power windows
AC
Charging

1) Is there a good schematic for the 2006 tundras? I am willing to buy one. I have a copy of the 588-page publication from Toyota but the schematics read more like a flow chart than a schematic.

2) After reading through the forums at Tundra Solutions I found four other threads with very similar problems, windows, radio, AC and but there were no solutions.

Thanks for any insight

ITO

Does anyone know where the grounding point BS is located? I see it in the diagram below but I have not been able to find it.

old87yota

Welcome to YotaTech!

To be honest, I do not know much about the Tundras, but I will try to help.

First, do not buy and replace parts that you are not sure are bad! That could get pretty expensive real quick!

If you still need wiring diagrams, you should be able to look up and download all of the factory wiring diagrams (most are interactive and color coded!) and repair manuals you want for a $15 two day subscription to Toyota's Techinfo website: https://techinfo.snapon.com/TIS/register.aspx

It is hard to tell from the diagram but the ground point BS looks like it could attach to the frame near the rear of the cab/front of the bed, or inside the cab under a trim piece that is probably covering the connection, but I am just guessing.

Have you checked that the battery terminals are super clean and shiny? Any corrosion to the battery cables? If so, fix that first. You say the battery is new so we probably don't need to worry about it.

Do you have a multimeter or a test light and know how to use it? It looks like you cannot do much more without one of these tools at this point.

The fact that your problems seem to occur when it rains hard or you put the truck into drive could be a clue, but it's not definitive. Do you have any leaks into the cab?

I have been watching an excellent YouTube Channel called South Main Auto Repair. I have learned that the easiest way to find an electrical problem that affects multiple circuits is to start with only one of the non-working circuits and don't worry about the other circuits. You could start with, say the turn signal circuit, and trace power and ground in that circuit, and find out where you are losing either the power or ground. You have a good chance of finding a common problem that way.

After re-reading your original post, I noticed you installed an aftermarket alarm system. Those systems, along with poor installation, seem to cause a fair amount of electrical problems. I would double check your installation of the system, and see if any of the wiring going into and out of the alarm box have anything to do with the items that are not working.

I hope that helps a little. I find it difficult for me to describe testing electrical stuff without actually being there to see the problem myself.

ITO

Yes, I have a meter and I know how to use it.

My plan is to verify that 'BS' is grounded properly, then I will start with one system and trace it back.

Thanks for the advice.

I got a service manual from Toyota and the schematics should be good enough.

Parts replacer...yep guilty. The battery was old, the alternator performing but it was barely above 12.6 volts, and the ECU was used and pretty cheap.

ITO

Old87Yota,

Thank you for taking the time to respond and offering to help. I took your advice and started tracing, here is what I found (see below). I am not sure how moisture got into the fuse box but it did. One the upside used fuseboxes on ebay are cheap, but I do need to find new connectors too.

ITO

Does anyone know where I can source the OEM wire connectors for on 06 Tundra?

I am about to contact the dealership but I am dreading their prices.

Option two might be a junk yard but I suspect they would want to sell me the whole harness.