horn problems

[duffbeer911]

hey all,
so my horn randomly just stopped working the other day. I use it a lot over here so can confidently say that it just instantly stopped working .... wasn't a gradual failure.

Fuse is OK.

I put a test light between the wire which hooks into one of the horns and an earth and I get no light when I push on the horn.

So, would you suggest I need to get the steering wheel cover off and check the switch? or is there something else I can check first?

Thanks for the help.

 

[IBallEngineer]

There is no Horn Relay, the Body ECU does the function of a relay. So you could check the horn switch and try grounding it directly. Next step would be checking the connections at the body ECU. There is power from the fuse, ground from the switch, and power out to the horns. You can see the diagram here.

http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/ewdtmc2/ewdtmpdf/ewdsourc/2002/024runne/systemci/046hs.pdf

:couch2:

 

[541joseph]

I know a friends 100 series LC had an issue that started with the horn then went to air bags and stuff because the body ecu went bad

 

[duffbeer911]

ok thanks for the advice. I checked out the diagram and I thought it would be simple enough to short out the switch... but I can't work out which wire is going to the switch?

This is the body ECU right? below the fuses?



I should probably be opening up the steering cover but don't have a torx bit with me so trying everything else.

thanks

 

[duffbeer911]

ok so I got the steering wheel cover off ... and the switch seems to working fine. The horns also work fine when I connect them directly to the battery.

Can anyone advise which wires in my picture (or elsewhere) are going to the switch and to the battery then I can bypass the ECU and see if that is problem.

Failing that, I'm tempted to just rewire the horn with a relay... but that seems like cheating

 

[IBallEngineer]

OK, so the information I have is from a 2000, which appears to have different looking connectors on the front of the Body ECU. But on mine it is a green wire with a red stripe going to the switch, and black going to the horns.
:couch2:

 

[duffbeer911]

ok thanks for the reply. I don't seem to have a green with red stripe wire .. so I tested for continuity between the switch in the steering wheel and all of the wires going into what I think is the body ECU and I don't get continuity on any of them.

So either there is a break between the switch and the ECU... OR I'm looking in completely the wrong place.

Any other advice? can anyone confirm that the horn switch does indeed lead to one of the pins in my photo??

thanks

 

[IBallEngineer]

I haven't been able to find a diagram for a 98 to confirm. I'm assuming you checked that there was no "horn" relay in the engine bay fuse block. It would be nice if we had a 98 manual.

 

[duffbeer911]

ok so I found the source of the problem! I removed the top steering wheel cover and the covers around the column. Unplugged the pins from the back of the steering wheel and when I ground one of the pins the horn sounds! So then i check for continuity between that pin and the horn switch and get nothing.
So there must be a break where the steering wheel connects to the column.

From what I've read I think I may need to replace this (the centre thing with the yellow sticker on it)? (picture take from another post). But I also don't have a steering wheel puller..... argh.

 

[duffbeer911]

looks like this post may solve my horn problem.

http://www.toyota-4runner.org/3rd-gen-t4rs/89398-how-install-clock-spring-k-spiral-cable.html

 

[IBallEngineer]

ok so I found the source of the problem!

From what I've read I think I may need to replace this (the centre thing with the yellow sticker on it)? (picture take from another post). But I also don't have a steering wheel puller..... argh.

The clockspring!

You don't need a puller, after you take the nut loose, leave it on the threads. Now hold the steering wheel on opposite sides and pull really hard first one hand, then the other. You'll be bending the wheel, but don't worry, it is tough. What you are trying to do is "break" the bond to the shaft which has a slight taper. Sort of like removing a ball joint from a spindle. I've done a hundred this way, always works.

:couch2:

 

[duffbeer911]

got it off without the puller, thanks.

Only thing now is finding a new one in Sierra Leone! seems impossible ... so will have to try and get it shipped from UK.

thanks

 

[IBallEngineer]

got it off without the puller, thanks.

Only thing now is finding a new one in Sierra Leone! seems impossible ... so will have to try and get it shipped from UK.

thanks

Oh shoot, I didn't realize you were in a furryn land! Hah.

Good luck!

:couch2:

 

[Zoverlander]

ok so I found the source of the problem! I removed the top steering wheel cover and the covers around the column. Unplugged the pins from the back of the steering wheel and when I ground one of the pins the horn sounds! So then i check for continuity between that pin and the horn switch and get nothing.
So there must be a break where the steering wheel connects to the column.

From what I've read I think I may need to replace this (the centre thing with the yellow sticker on it)? (picture take from another post). But I also don't have a steering wheel puller..... argh.
View attachment 109926

THANK YOU for posting this! I have the same problem...and now know how to fix!

 

[Zoverlander]

The clockspring!

You don't need a puller, after you take the nut loose, leave it on the threads. Now hold the steering wheel on opposite sides and pull really hard first one hand, then the other. You'll be bending the wheel, but don't worry, it is tough. What you are trying to do is "break" the bond to the shaft which has a slight taper. Sort of like removing a ball joint from a spindle. I've done a hundred this way, always works.

:couch2:

This information is like gold - thank you so much for posting!

I have this same horn problem in my '97 - but fortunately also have a donor '96 sitting in my driveway Is my understanding correct, that once I loosen the nut holding steering wheel to the column, I can break the bond to the shaft with your technique, and then just swap the entire steering wheels (this 'clockspring' or whatever that thing with the yellow sticker is called will come too)?

 

[IBallEngineer]

This information is like gold - thank you so much for posting!

I have this same horn problem in my '97 - but fortunately also have a donor '96 sitting in my driveway Is my understanding correct, that once I loosen the nut holding steering wheel to the column, I can break the bond to the shaft with your technique, and then just swap the entire steering wheels (this 'clockspring' or whatever that thing with the yellow sticker is called will come too)?

Yes, but you must take care with the "yellow" connectors, those are for the airbag, so watch this video to see the precautions you should definitely take to ensure you don't mess anything up! This is a forum member who does a great service to the forum making how to videos.

YouTube