Electrial - Horn - Cruise

[lwgregory]

Have a 95 Windstar that the Cruise does not work and the horn works in the off position. Does not work with key on.
Told problem with wiring in steering column, so changed columns, but still same result.
New horn relay, fuses ok.

[ModMech]

Changed what?

[lwgregory]

Steering column changed sill no difference

[ModMech]

The horn is fed from the battery, it's not supposed to be on switched power AT ALL. So, it's my guess that someone installed an alarm, remote start, remote door unlock etc., and butched the wiring.

[lwgregory]

Factory installed panic alarm only, operating from door unlck button.
Ford Motor mechanic says that horn works off the baterry till you turn key on then switches to fuse panel through horn relay.
No after market modifications have been made to botch up wiring.
Mechanic says $55/hr to trouble shoot.
He says that if not horn relay it was in steering column and that cruise not working was just a coincidence.

Horn wire has two leads - 12 volt to one, 0 on other lead with key in off position. 12 volts on both leads with key on.

Sounds like a missing ground to me but unable to find

[ModMech]

AaaaHAAAAAA!

You have a bad ground point. The horn wires should ALWAYS be +12V and Ground, the "other" should NEVER show +12V, never.

This means that the common ground point (where the horn wire is grounded) is open (broken), not connected, or loose. When you turn the key on, other things are gounded to the SAME ground point as the horn, but if they cannot ground either due to a bad ground, you will see voltage in ALL the ground circuits of every device that should be grounded togather.

The horn works like this:

BATT > Fuse^a > Horn relay > Horn
and
BATT > Fuse^b > Horn relay > Horn button > ground

So sinve we KNOW the relay is ok (horn does work) the main power for the horn is also good (top line). The horn switch grounds the relay, and when it does (can) the relay closes sending power from Fuse^a to the horn. Since the ground is open, when you switch the key on, other devices put voltage in the horn ground wire preventing it from closing the relay.

The problem is, you MUST find out where the ground is, and FIX IT, because other systems need it to work properly, so just grounding the horn wire to a new location is a temporary patch, but would work.

[wgm]

Originally Posted by ModMech

AaaaHAAAAAA!

You have a bad ground point. The horn wires should ALWAYS be +12V and Ground, the "other" should NEVER show +12V, never.

This means that the common ground point (where the horn wire is grounded) is open (broken), not connected, or loose. When you turn the key on, other things are gounded to the SAME ground point as the horn, but if they cannot ground either due to a bad ground, you will see voltage in ALL the ground circuits of every device that should be grounded togather.

The horn works like this:

BATT > Fuse^a > Horn relay > Horn
and
BATT > Fuse^b > Horn relay > Horn button > ground

So sinve we KNOW the relay is ok (horn does work) the main power for the horn is also good (top line). The horn switch grounds the relay, and when it does (can) the relay closes sending power from Fuse^a to the horn. Since the ground is open, when you switch the key on, other devices put voltage in the horn ground wire preventing it from closing the relay.

The problem is, you MUST find out where the ground is, and FIX IT, because other systems need it to work properly, so just grounding the horn wire to a new location is a temporary patch, but would work.

ask you mechanic if he checked the click spring in the column?????

[wgm]

Originally Posted by wgm

ask you mechanic if he checked the click spring in the column?????

sorry should read clock spring... it's in the column at the base of the steering wheel...

[bdixon]

I have a 1996 Windstar and worked on a similar problem for 6 months before fixing it.

My symptom was the horn being on without pressing hte horn .... I had to remove the horn fuse to drive the car. In the end I attached a string to the fuse with a large red flag that could easily be yanked while driving along since the horn mostly cam on when turning right hand turns.

When all this occured the cruise control would stop. Upon studying the scmematic, it works out that to save a wire through the clockspring, the +12 line from the horn relay also powers the cruise control switches. ( this is a neat design feature since you shouldn't be using the horn and engaging cruise control at the same time ! ) Anyway as the above answers imply , a short may be on your horn switch.... I traced my short to the bottom of the steating column where the wire loom to the clocksspring ( in the steering wheel) was under tension and the insulation had worn to expose copper that when turning right would short to the metal of the steering column. I repaired it with some electrical tape.

I contacted Ford as I thought it was a potential saftey issue if the airbag wires got shorted. I hope this helps. Of interest is that the failure is not a clockspring failure .... but in chaning the clockspring .... the cable loom attached is also replaced and the whole thing should be working again.

[lwgregory]

Thanks for all suggestions, but even Ford mechanic retired the issue with a 185 dollar bill. Could not trace problem, but offered to continue for a price. Ya?|

[bdixon]

Gregory, I find it difficult that Ford gave up on this. I can't remember ... is it intermittant ?

Ford has a secret maintenance data base which is a collection of all past knowledge regarding faults for a given year/model. The horn sub-system isn't that complex and they should be ashamed of themselves for 1) giving up and 2) asking you to pay up.

If you live anywhere near Austin TX. I will help you fix for free.

I will check what the Ford maintanence data base has for the fault you describe. Give me a few days.

[Mingo1]

where r the relays and actual horn located.