Flash switch works, but high beam switch does not

I have an (unmodified) Tacoma lighting issue. My high beams are clearly working: when the flash toggle is on, the relay engages and the high beams come on. But when I use the high beam switch, it is like nothing is happening: no relay, only low beams, no change in the voltage to the relay.

I have tested the relays and the fuses, and I replaced the dimmer/turn-signal switch with the exact same results.

One more clue: I don't know if this caused the problem, but I changed my clutch master cylinder recently, and followed a Tacoma manual, removing the interior fuse and relay box (unnecessary, I should have followed my instinct). In the process, I have two plugs that I could not find a place to put in. Perhaps I am missing something?

 

Those are for switches on the dash you don't have. I suggest you remove and re-insert every connector to the interior fuse box. If by any chance they are not seated completely gremlims pop out. The headlights have the switch and the inside of the fuse box to activate them.

 

My first gen is doing the same thing. I'm guessing it's the same issue. Your thread came up in my search.

Did you get it figured out?

 

OK, I found connectivity between the low switch, flash switch, but not the high switch. I don't understand what is between the connectors, another fuse?

 

The headlights (Low & High) have the fuse after the relays HEAD & Dim. 1L is a connector from the BECU to connector C11 (Stalk switch) Have you tested the stalk switch for continuity? Remove C11 and test contact 11 and 12 on the stalk not the connector. (12 is common ground on stalk).

 

If you know the switch (stalk) is good then, unfortunately, it's pointing towards the BECU. Turns lights off after IGN off when door opens and a few other things...

 

When I test the C11, contact 11 goes to red-green wire (R-G in the diagram, I assume), and leaves the C11 correctly (I tested contact 11 and the wire). But there is NO connectivity from C11-contact-11 to any contact on the B5 connector.

When I look at the diagram for the C11, I see:

1. port 20 (purple wire) - low lights
2. port 17 (red-white wire) - flash
3. port 11 (red-green wire) - high lights

Is this correct? Where would that red-green wire lead to from the C11?

 

OK, folks, it's now working again. I disconnected all of the cables to the Body ECU, briefly looked it over, then reconnected each connector carefully. Apparently that did the trick.

Thank you to everybody who helped me out. A few lessons learned:

• Avoid cheap spiral switches. If they seem too cheap to be good (less than $30), they are. Go with a used or new OEM spiral switch.
• There's no need to remove the BECU when replacing the clutch master cylinder. I followed my Haynes manual, which said to remove the BECU, but it is definitely better to try to keep all the electrical wiring in place.
• After reinstalling the BECU, if problems pop up, take a deep breath and try removing everything and reinstalling it
• Attach small sewing pins to alligator clips to test connectivity in the connectors
• Obviously take photos before and after to simplify the rewiring. There are usually (always?) connectors that are not used

 

Told you the gremlins would pop up...Glad you got it working

 

Hey guys. I have a 2001 Tacoma with this very issue. Can someone explain to this crippled up ole lady how to fix this issue. Pictures would help. I'm pretty handy. Live on the farm but have no idea what all the parts are people are talking about. Thanks for any help.

 

https://www.tacomaworld.com/threads/high-beam-switch-bad.452150/

This is likely the issue for you if you haven't installed anything lately. Mine just crapped out, or my son just got a hold of it...

 

Thanks. That was very helpful if I had the money for a new switch. At least I can drive it the way it is.