Solved - Horn Stopped Working

Seconds before some asshole backed into me at the supermarket I discovered that my horn no longer works. I can't remember the last time I used it TBH. The cruise control still functions.

As a diagnostic I hit the red panic button on my key fob, and the horns blared loudly. So I'm thinking that the fault is on the other side of the relay. That leaves the horn switch itself (eh, not likely IMHO), or the dreaded Spiral Cable (more likely, me thinks, because the PO had it changed ~ 4 years ago to pass inspection). In the back of random stuff he gave me was the old spiral cable (not OEM) so I'm not confident that he replaced with OEM.

(Full disclosure, my SRS light has been on since I got the car, more or less. Actually, it came on after I bought a new battery in the first weeks I owned it. I later took it to the stealer for an open airbag recall hoping maybe the light would go out, but no cigar. "Open squib circuit" they said. Later, when I got my own copy of Techstream, the failure was..."open squib circuit". Also BTW, my Techstream now complains about "license activation", so I have to go through the whole re-installation process, which I'm not in the mood for right now.)

So as I said, I'm leaning toward the Spiral Cable being the culprit. Before I go that direction I'd like to try testing then bypassing the horn switch to preclude that as the fault. I've found one or two threads here that deal with that (BTW, the search function sucks!). What I'm still looking for is any information (pictures!) that show exactly where the horn switch is, and how to change it if bad.

Does anyone have any wisdom to share?

 

While this is a 2000 thread it’ll apply to any 1st gen and it’s just one of many we’ve had overtime. While the video link contained in post below is long, it gets you to the horn switch and how he tested at about 22 min mark.

https://www.tundras.com/threads/2000-tundra-v8-horn-relay-location.124180/#post-3179926

 

Excellent...thanks!

 

So...I spent a few days debating whether to buy an OEM clock spring ($300) or some cheap nameless import ($30 - $50). Finally I went for the OEM (but I had to get a second mortgage to afford it!).

The one on top is the shiny new OEM part that I got from McGeorge Ourisman Toyota. The one in the middle is the one I removed (clearly NOT an OEM part). The one on the bottom was given to me by the prior owner in a bag of miscellaneous parts that had been changed on his watch (I guess I'm not the only one who saves the old parts).


This is my shiny new clock spring installed just before closing the patient. The horn now works, cruise control still works, and the SRS light is now out! (I assume the airbag will work, but I hope that I never have to find out).

 

Speaking of “Ourisman Toyota”, is it too early to tell how the new owners will be compared to when it was McGeorge ?

 

Win!

Squib circuit + horn would've probably led me to clock spring, but I'd have doubts paying that much for OEM part unless something else wasn't working (like radio controls if present)

This just lends more credence to OEM vs. aftermarket though. If the PO had bought OEM, you wouldn't be here replacing it a short time later...

 

I spoke to them. Said it's business as usual! That said, however, they bumped the "standard shipping charge" to $27!!! I complained, and they said they'd price match whatever I could find at another Toyota online parts seller.

Edit: And there is no more "freeship" option. They took it down months ago.

 

Turns out that the yellow connector going into the bottom of the existing clock spring was loose (I was already committed to the new one by then), and on closer inspection I saw two of the 4 pins were munged up. So PO had the combination of cheap parts and inferior skills.

 

Coming back to quote on this b/c I noticed something while digging up this post for someone else.

I'm happy to see someone else whose tilt lever has that v-shaped crack on the tab. I guess it's more common than I thought. that lever is one of the cheapest-looking pieces on our entire trucks. And I think there was either rubber or bristles that covered the hole it goes through in the column plastics from the factory which fall out/off? But Toyota doesn't sell a replacement, so you just get a big open hole in the plastics. My one pet peeve on the column.

​

 

The lever can be had. Or did you mean the missing bristly bit?

https://parts.lakelandtoyota.com/p/TOYOTA__/Steering-Column-Tilt-Adjuster/3999888/4582607010.html

 

Bristly bit.

 

I had a similar non-functioning horn on my '05 DC a few years ago. Dealer said it was a spiral cable issue. After the 2nd spiral cable was installed and the horn still didn't work, they determined that it was not a spiral cable issue. The issue ultimately was determined to be an electrical short caused by the loss of grease over time. I believe the loss of grease and associated short was in the steering column - Shifty will hopefully know and can provide more specifics. Anyway, it was an easy fix once they identified the short and applied some grease. Might be something else to be aware of.

 

So, the only thing that makes sense to me here is, there's an electrical contact in the airbag housing (which doubles as the horn button). Two pieces of metal that need to touch together to complete a circuit (ground, I think?), but they're not actively touching anymore. I haven't heard of people using grease (but maybe dielectric grease is at the heart?) to solve the issue, but that would be interesting if, after years, you just need to lube a contact point at the back of the airbag housing.

For the couple (2-3) dudes who've found this was their case on here, it was only the horn not working, and sometimes it would work if you pressed from the right angle. The people who have bad clocksprings typically had another failure for a component passing wires thru the clockspring, whether that be radio controls, cruise control, or something else (I can't think of anything else).

If two things are bad, i.e. no horn plus one of the two items I just mentioned, it's almost always the clockspring. If it's just the horn ... that's when add'l debugging is needed.

 

Scroll up...the link above shows how to trouble shoot the horn circuit

https://www.tundras.com/threads/solved-horn-stopped-working.131267/#post-3340006

 

I did a Google search and found a thread from Tundratalk.net (didn't know there was such a forum) that discusses the electrical short in the steering column that caused the issue with my horn. Short version is that grease is needed in the steering shaft bearing. If the grease is gone and the bearing is rusted, then the shaft won't ground properly and the horn won't work. And I don't recall any rust on my steering shaft bearing, so the issue can occur if there is inadequate grease.

https://www.tundratalk.net/threads/2000-06-tundra-horn-issue-resolved.107211/

 

Hell....it's not every day that Shifty might learn something from me. Even though it was probably a minor issue that he forgot about, I'm going to pour a bourbon and soak it up. Hope this string saves somebody from having to buy a spiral cable and install cost/effort when just a little grease on the steering column bearing is needed. And thanks Shifty for everything I've learned from you!

 

Hey gents, really appreciate all your input and advice on this topic. I was hopeful the lack of grease was the problem (and it may still be) but I tried the horn every 90 deg from lock to lock and didn’t get a peep. I’ve got an ‘18 and the only thing that doesn’t work on the steering column is the horn. Horn does work when you hit the alarm button. Did a fair amount of research and it seems OEM clock springs are now $424 minimum. Generic are still about $200 but I don’t trust them. Before I drop the $424, is there anything else I should check? I figure my plan of action is to have the clock spring in hand, pull the wheel, hope I just need to do some greasing but if not, install new clock spring. Would you try anything else? Thanks again!

https://www.sparksparts.com/oem-parts/toyota-cable-sub-assembly-spiral-with-sensor-843070c020

 

Your 2.5 gen model Tundra is probably significantly different from the 1st gen model we're chatting about here, I dunno if the grease situation applies. I'm also not familiar with how the 2018 is wired. Is the alarm you're talking about the factory alarm, or one of the shitty dealer-add-on ones tens of thousands of buyers got sucked into accepting?

 

Pretty sure it is the factory alarm. It’s a Platinum if that matters.

 

Given my limited knowledge of newer Tundras (the rest of us over here in 1st gen section are probably similar in that right), the fact it's working with the OEM alarm which probably intercepts on between the clock spring and firewall, but not working with the horn button which intercepts between the clock spring and steering wheel ... the first thing I'd be doing is getting the wiring diagram for your truck, which should be in the Tundra/Sequoia wiring diagrams thread, looking up the wiring colors passing thru the clockspring. Then I'd be popping off the wheel and steering column plastics (if the latter applies to the newfangled models, and testing continuity on the horn wiring with a DMM. That will very quickly tell you if you need a $400+ clockspring, or, if it's showing continuity, you need to be barking up another tree (likely the horn assembly, which may be integrated with airbag module...)

That's just my 2¢, some logical deduction and troubleshooting, given you're a newer truck owner and replying to a thread in the 1st generation subforum that's the best I can do. You may want to post in the 2.5 Gen Tundra subforum for more-model-year-specific help.

 

Awesome man, I appreciate your help. I looked at a bunch of clock spring / horn not working threads and you guys seemed to be the most clued in so I really appreciate your feedback.

 

Before I type more, in case it wasn't stated clearly above in the thread, ALWAYS REMOVE THE NEGATIVE BATTERY CABLE AND WAIT 5-10 MINUTES BEFORE TOUCHING/PROBING/REMOVING ANYTHING AIRBAG/SRS RELATED. (sorry if you know this, standard disclaimer, don't want anyone to get hurt)

You generally understand how the clock spring works, right? May help you troubleshoot, before you parts-cannon this MF'er, and waste $400-500 on a replacement part that's A-OK.

If not, if you've ever seen a ribbon cable, it's pretty much a long one of those wound up inside a disc with plenty of slack, enough slack that you can turn the steering wheel a couple of rotations before it tightens up the slack to the point of snapping. The ribbon cable typically has several wires running thru it, each to attach a different circuit. Sometimes not all those wires are used. There's a input/output pin for each wire inside that ribbon cable at the top and bottom of the clockspring disc itself, example shown below.

Sometimes, if people have to remove the steering wheel and are haphazard about how they reinstall, one of the contacts can get tugged because they reinstalled with too little slack, and when you go hard-lock left or right, *YOINK* you'll rip out one or more of the contacts. Sometimes they just naturally fail, and other times, people make the really piss-poor mistake of using an aftermarket part (please, DO NOT use an aftermarket part here, your life may depend on it!) so it's just generally poor quality with no QC.

During install/removal, there's a specific way/indicators on how to align the clockspring, and you always start with the wheels centered and wheel at 12 o'clock pointing north before removing the wheel, and always reinstall the clockspring with the "up" arrow on it pointed due north. Again, I presume this is the same for your later-gen.

You may not actually need to dig very deep to probe with a DMM (multimeter). Basically the two black protrusions you see poking out of this example are the input/output for the spring itself. Anything with an orange connector is ALWAYS airbag/SRS, so you can safely ignore those wires, and that should leave very few wires to probe with your DMM. You just need to find a way to get access to the pins of the connector on the "Steering column" side of the clockspring, then pull loose the black connector from the back of the airbag assembly (typically).

Wiring diagrams thread is here so you can figure out which pins to probe on the steering column side of the clockspring.

​