Today I installed a Momo steering wheel which came with a horn button. My problem is that the horn will not work. The adapter has a separate steel like rim that has a provision for the ground and the so called horn button is just a plastic piece that snaps into the center hole.

To me, there does not appear to be any movement in the horn button itself and once installed it does not depress and seems pretty solid. I haven't a clue how this system might work since there is no movement in the cover and no metal to metal contact that I can tell. Does anyone know if this may be just a cover and not really a horn button? Or, do I have to make any other connections to get the horn to work? Appreciate any insights……

Thanks,

George

The back of the horn button should have a electrical spade connector, which when it ground sounds the horn.

Sometimes you have to bend the factory copper arm upward to meet the Momo copper connection ring on the back of the wheel adaptor.

The horn button on my Momo is spring loaded (has a spring behind the button) not solid like yours. Maby there are some missing peices.

Curtis & Christopher, Thanks for the info…. My Momo button has no connector and no spring on the button with which to make contact. It is entirely made of plastic with three small prongs which get pressue pushed into the center hole.

The adaptor came with a separate ring that has a spade up at an angle where the ground connects too. When you push the horn button it is flat, does not move at all, as you would expect it would if it were spring loaded—it is just solidly in there.

I am inclined to think that I do not have a horn button but rather just a plug with the emblem to cover up the hole. That’s great… as I paid for and thought I was getting a horn button…..I greatly appreciate the advice…. I guess I will now look for a real horn button and see what happens….

Once again, thanks,

George

MSA sells a horn button that has the Datsun "Z" in the center. It will fit a Momo steering wheel, but does your adaptor have the horn wire coming out of it?

MSA sells a horn button that has the Datsun "Z" in the center. It will fit a Momo steering wheel, but does your adaptor have the horn wire coming out of it?

My Adaptor, which I purchased from MSA, does not have a wire at all.... The ground wire comes from the steering stalk.... there is a metal ring that came with the adapter and this ring has a tab which is where you attach the ground.... and this ring is placed between the adapter and the wheel.

There were no instructions with the adapter.... only a two page write-up about tightening the bolt so your wheel doesn't fall off (which I found most helpful by the way.....)

The ground wire comes from the steering stalk....

Test this wire to see if it is a ground wire. Sounds like this is the horn wire. Try and ground it.

I'll take the wheel off tomorrow and give it another try.....

Curtis,

The silver ring with the male spade is the GROUND connection. Some horn buttons do not need it as their spring retaining cleats also serve as the GROUND connection.

First thing you need to verify is:

1. Is the copper finger on the steering column contacting the copper ring on the back of the Momo wheel adaptor? If not, gently bend it upward to meet the copper ring.

2. Now there should be a wire coming through the Momo adaptor (it is connected to the back of the copper ring). If there is more than one don't worry, momentarily ground the wire. BTW, the steering column shaft is grounded so just touch the wire to the steering shaft. If the horn sounds then that is the "hot" wire.

3. The "hot" wire should be connected to the back of your horn button. If there is a question of where to connect it on the back of the horn button, the connection is usually insulated from GROUND. So when the horn button is mounted in the adaptor AND THEN you press the button, the "hot" wire is grounded which triggers the horn.

4. If you have another male spade connection on the horn button it is the GROUND connection and you just need to make a short jumper wire to the silver ring spade.

Thanks Curtis.....

George,

Sorry for the late response, I had to go home and look at my electrical schematics.

The horn circuit is hot all the time. The power for the horn comes from the horn fuse in the fuse box. The horn fuse (10 amp) is the second from the bottom on the left side.

The horn is operated via a horn relay located in the driver's foot well. It has three spade connections on it. The green wire goes to the horns. The green with red stripe comes from the fuse box (and should have 12 VDC on it all the time). The green with black stripe come from your horn button.

First check if the green with red stripe has 12 VDC on it. If it doesn't then check/replace your fuse.

If the green with red stripe wire has 12 VDC, then ground the terminal on the horn relay that the green with black stripe wire is attached to (this simulates you pressing the horn button). If the horns still don't work, leave the terminal grounded and check the for 12 VDC on the terminal that the green wire is attached to. If you have voltage on the green terminal you know the relay is working. Then you need to check if have voltage at the horns, if not then the green wire is broken somewhere between the horn relay and the horns.

If you don't have voltage on the green terminal, with the green with black terminal grounded, then the horn relay is bad.

If the horns work when you grounded the green with black terminal, then you need to run a new wire up to your horn button.

I hope this covers all your scenerios.

Curtis

Curtis,

Got the horn working thanks to you..... Ran through all the checks you suggested. Turns out that I was not getting any hot connection through the Momo adapter. Didn't seem to matter what I bent or how far I bent it no hot was coming through. Therefore, armed with the info you provided, I re-wired the horn and now it's working.....

Once again, Thanks,

George

Uhhh... dumb question here, but...

Can someone tell me the size of the steering wheel nut offhand?

7/8 works on it!