Peter 642

Bought my first 944 today. Fantastic car!
Last owner replaced the wheel with a Momo, and the horn never worked.
We took a look at it; wires are connected, even switched out the horn itself, but there's no power to the horn. Dead.

Easy fix? Do I need to re-wire my horn? We couldn't find a blown fuse, either.
Won't pass inspection as-is, and it's a daily driver.

Thanks.

b5audia4

I have the same problem - someone chime in.

Crimson Nape Racing

if the steering wheel was replaced I bet it's the horn ring - either not working or not hooked up. I don't know about your wheel, but you may be able to pop of the horn button and look to see if the wires are connected. Some set-ups have a little metal spring thing to transfer electricity thru the horn button.
Mine broke or was lost on my 71 and I made a new one with a short (1/2" maybe) piece of a pen, the spring from the pen, and 2 metal caps from the pen. It worked for the 8 years I had the car.

johnnykrand

Either faulty wires (like inside the casing). BUT! my guess would be the magnets in your steering wheel are stuck together maybe have a look at that and see if you can unstick them.

Lizard944

I think there is a small ground wire for the horn that connects to the middle of the steering rack or cross-member. Can't remember which. Anyway, now is your chance to get that bumper sticker that says: "Horn out of order, watch for finger."

Grandpa#3

The steering column shaft has a ground wire left side engine compartment.

Cheers,
Larry

ZR8ED

Sorry not much help for the no beep, though mine makes a beewahhhhp kind of embarrasing sounding. I think it may be a poor ground as well.

Does the horn work if you put direct power to it? If so, then as others have stated..check the ground, and/or pop off the centre cover. The horn button setup on the steering wheel appears to be quite delicate looking.

Good luck!

Peter 642

It's not the wheel; we tried that. No power to the horn itself (in the engine compartment). We tried switching horns, didn't work.

Thanks; I'll try the ground wire in the steering column.
Any pics of the wiring that you know of, in case I need to rewire the whole thing? Couldn't specifically find on-line.

msailer

I have the same problem in my '83 944 NA. Here is the way it works in my car and I'm sure in all the following years.
- Horn button provides a ground for the horn relay. The relay is what really provides the +12 VDC to the horn
- The ground signal is passed up the steering column center shaft - the piece that turns. There is a ground wire down by the crossmember where the steering rack is bolted to. The wire goes from the cross member to the steering rack.
- Behind the steering wheel there is a copper looking flat spring piece. This is connected to the relay control circuit.
- On the steering wheel or in the case of aftermarket wheels, the adapter; There is a copper clad disk that will rub on the flat spring. The horn button has a wire that connects to this disk. After market horn buttons, pick up the ground from the spring retaining wires on the side of the button. Remember the ground comes up the steering shaft; the steering wheel adapter is bolted to the shaft; the steering wheel is bolted to the steering wheel adapter.

Confused? That is the path of the ground and I believe the source of most non-functioning horns. aka - missing ground.

Troubleshooting: ( you will need a meter and a few alligator clip jumper wires)
- remove steering wheel and adapter if so equipt
- using a jumper wire, attach one end to the flat spring contact and the other end to a known good chassis ground. If the car is in the run position, the horn should sound. This will show that the relay, fuse and the horn itself are good.
- Next, do we have a ground thru the steering column. Using your meter in the ohms or resitance position. Connect one lead to the jumper attached to the known good chassis ground. The other lead from the meter touch the center of the steering shaft. You should get a reading that is less than, my guess, 100 ohms. If you do not have a reading, there is a problem getting a ground thru the column. I have this problem.
- If you do get a good ground, then using a jumper wire from the center of the steering shaft to the flat spring contactor should sound the horn, when the car is in the run position. If this is the case, you have a problem with the horn button or the attached wires to the button.

msailer

My problem is with the ground coming thru the steering column.
I have replace the wire at the crossmember and it still doesn't work.

I think the next step is to take apart the steering shaft and clean the places, top and bottom, where it slides onto the splined ends of the steering rack and the steering column. There is probably rust/corrosion built up at those points.

For those who have pulled the steering apart, what is the easiest way to get the shaft out with minimal work? Dropping the rack seems like the least amount of work.

Funn944

Could be the contacts in the steering wheel, the contact ring in the column, broken wires in the column,
fuse, there is also a relay for the horn, bad ground anywhere in the horn wiring, or a dead horn.

The contact ring in the column on mine came loose and the horn would either not work, or just honk on it's own. Just had to epoxy it back in place.

dv8nxs944

I had the same problems. i just fixed mine. Check this thread out.

https://rennlist.com/forums/924-931-...some-help.html

peanut

if the supply to the horn is fed through a relay I'd check the relay is working. Have you got a schematic ?

peanut

ok heres the schematic
http://www.pelicanparts.com/944/elec...944_84_3_2.jpg

The horn works like this.

Power is fed through the relay to the horns and then to earth . That supply is constant and broken only by the switch in the relay.

When you press your horn button another live feed is taken through the relay coil through the horn button to earth. Whilst the second supply through the relay coil is earthed the switch in the other half of the relay is switched closed passing the supply to the horns.

In other words the horn push only operates your horn relay not the horns directly.
Simples
So you need to check the 12v+ power supply to the switch and the coil on the relay, check the fuse and check continuity of the wiring of the whole system and obviously the earthing to both the relay coil and the horns

peanut

ok to faultfind your horn circuitry this may be a help.
Use a multimeter set to DV volts 0-20volts range . Place the black probe (earth) on a suitable earthing point on the chassis then use the red probe to check the following.

With the ignition off

Check that you have 12v+ at the horn fuse (No3 on my S2)
Remove the horn relay
Check that you have 12v+ at horn relay socket No 30

Turn ignition on
Check that you now have 12v+ at relay socket No 85 and 86

Operation .
Turning on the ignition puts 12v+ across the horn relay coil terminals 85 & 86. When you press the horn button the horn relay coil is activated which connects the horn relay switch terminals 30 and 87 .
The 12v+ sitting on terminal 30 is then connected through terminal 87 on the relay and then to earth via the horns earth which activates the horns.