Help with Horn Button ( not working)

[floatinghead]

Two things to note:  I’m a relatively newbie mechanic even though I’ve had my 02 for a while.  This forum is a huge resource though.  I searched through lots of different horn button issues which helped, but hasn’t pushed me across the finish line on this one to get it fixed.

 

Background: A friend gave me a momo copy steering wheel over the summer to replace my original bus wheel and have enjoyed the new feel and size, but didn't have a horn button to finish the job.  I had to tape the end of the wire on the wheel inside the hub because it would complete the circuit and make the horn beep while turning.  Since then my mechanic did some work on the car (not horn related: new springs, tie rods, water pump) and when I recently  bought an Ebay horn and went to install it, i noticed the wire in the wheel wasn't making the horn beep when it touched the inside of the hub.  I pulled the new wheel and put the old one on and still got nothing.  Wasn't sure if something got bumped or pulled when my mechanic was fixing the other stuff or maybe I did something in that time. 

 

OK, so some things i've checked:

- horn does work ( connected wires to a power source and it beeped!)

- relay "seems" to be working.  My multimeter was on the fritz, so didn't check resistance across it.   Red wire to 30 is getting power.  Tested it off the car first (with 9v battery on switched portion and heard clicking in relay) and then when it was back on the car, i pulled the switch wires on the relay and connected a 9v battery and I could get the horn to fire.  So i'm thinking its something between the horn/column area and the relay.  The connections at the relay were pretty crusty, so i sanded them back to bare metal as best i could, though not inside the clips very well. So I guess I’m not completely confident in the wires from the relay to the column, but they did work like that for a long time.

- The steering wheel hub is making contact with the brass ring on the column via sprung pin.  With the wheel off, I tried to bridge the gap between the brass ring and the column with a wire and got nothing.  I couldn't hear any clicking of the relay either, though didn’t have a helper to check.

 

• Any thoughts on what this could be or what I should check?   

•How do the wires from the relay routes back and connects to the column? 

• Any pics or diagrams, though wiring diagrams are confusing….?  

 

Thanks,

 

Baron

[Tsingtao_1903]

There is a ground strap electrically connecting one side of the steering shaft to the other side of the flexible disc.  (One of the bolts on part 1 to one of the bolts on part 5).  The ground strap is not shown in the illustration below.  Check to see if yours is still there and is making good connection.

 

[2002Scoob]

IT is shown, its #3, and isn't as much a 'ground strap' as it is a little wire spring that's wound into the center of the guibo that connects one stud from the steering-box flange to another stud of the steering shaft flange and likes to rust/become corroded/ cause intermittent failures of horn buttons. 

 

When I replaced my Guibo, I had similar issues (as well as a faulty horn button that was always on to begin with), so that when changing lanes, turning, or any other minor steering input, the horn would sound. Good thing 02's are as friendly faced as they are, otherwise I'm sure everyone thought I was the rudest asshole driving around honking at everyone and everything!

 

I think a better solution would be an actual quality ground-wire with quality eyelets that go under those flange bolts would be more robust/reliable. 

Edited January 26, 2018 by 2002Scoob

[Buckeye]

This one is more of visual help

 

[2002Scoob]

Looking at Buckeye's post there indeed seems to be an actual 'strap' there as well. perhaps there were a few solutions to this issue. 

[Simeon]

There are a few different styles. The central spring, the woven strap and the ‘wound up paper clip ‘. I would just get some ring crimp terminals the appropriate size for the bolt holes and a short piece of wire to crimp between them. 

[MitchaPaLoOza88]

I didn't really read the other comments, but I had very similar symptoms with my horn.

 

Turned out it was the spring loaded contact looked like it was working but it was actually gummed up and not springing properly. A little PB Blast fixed it and it was working fine again.

 

Just throwing it out as a simple check.

[floatinghead]

Thanks all for the info.  Maybe the spring/ground strap around the steering guibo go bumped or pulled out while my front end work was getting done.  I'll take a look tonight and report back.  I assume I need to do from below the car?  I have a tii....

Edited January 26, 2018 by floatinghead

[Tsingtao_1903]

5 minutes ago, floatinghead said:

 I assume I need to do from below the car?

You can see the steering giubo once the hood is opened without getting under the car.  

[Mike Self]

Keep in mind, too that the horn circuit is activated by the ground side, not the hot side.  The horn push button on the steering wheel actually grounds the horn circuit to complete the electrical path between horn and battery, so you need to trace the ground path beginning at the steering box and working back towards the steering wheel push button.

 

mike 

[floatinghead]

Mike, thats what I was a bit curious of.  At the relay, the Red is hot from the battery, the yellow/green goes out to the horn i think ( though it has 2 wires at the connection so not sure), and then a black/brown and yellow/brown wire that go into the harness, but not sure where they go.  

 

What connects the brass ring on the column to all of this?  one of the brown wires?

[Mike Self]

17 hours ago, floatinghead said:

What connects the brass ring on the column to all of this?  one of the brown wires?

I've never traced the whole horn wiring link, but as brown wires are almost always grounds on 2002s, and we know that the brass ring on the steering column is on the ground circuit, I would presume that there is a brown wire running down to the steering column and eventually on to the relay.  You should be able to make the horn honk by grounding the brass ring; if you can't, and the feed wire at the relay is hot with the ignition on, then there's a ground problem somewhere.

 

mike

[floatinghead]

Hi there,

 

I haven't gotten it working yet, but had  few more questions.  I tried to piece together a drawing of the horn circuit based on some different threads on the FAQ.  Let me know if this is looking right or if I have something wrong, which is highly likely!  Mostly trying to figure out the 85 and 86 leads and up to the column.    If this is correct i had a few questions based on the attached drawing:

 

A. Guibo on the column:  I tried to get to the guibo area, but man this is a tight spot.  right under the brake booster, so wasn't easy for me to loosen the bolts and add a connector wire.    Can I check resistance with my multimeter first on either side of the guibo to see if there is indeed continuity there?  If there is, then its something else.  if not, then this may be the trouble spot.

B. Does the 86 wire ( black and brown?) come from the fuse box and brass ring on the column?  I am going to check to see if this connection is hot when ignition switch is on and horn button pushed.  

C.  Does the 85 (brown-yellow) go back to the horn?  I noticed I have 2 green-yellow wires on the 87 connection on the relay, but only have one horn. Are there supposed to be 2 horns?

 

Anything else i should check ?

 

 

Horn-Electrical Diagram.pdf

Edited January 30, 2018 by floatinghead

[Buckeye]

Don't know what year car you have, but this could help possibly

ELECTRICALCIRCUITDIAGRAMBMWcolor.pdf

 

[floatinghead]

1 hour ago, Buckeye said:

Don't know what year car you have, but this could help possibly

ELECTRICALCIRCUITDIAGRAMBMWcolor.pdf

 

I have a 73tii, so think this should be accurate.  This is nice to nice to have, even if i wasn't having this problem, so thanks!   I think i have a few more questions, but i'll wait till i can check a few things on the car tonight.