91 Mk2 Horn Switch Problem "Please help"

[johnr]

Hi all, Need your expert help badly. My horn never did work when got the 2. To the point..The fuse and relay both OK. Jumpered "relay" from power side to horn side and yes I have a good horn. I decided to troubleshoot the relay contact(GRN/BLK) wire back to the "last" connector in steering column. I found I still had good continuity. I then decided to safely take apart the steering wheel etc. down to the so called spiral cable unit. Prior to that step I also completed a steering wheel continuity test with the 2 horn contacts, no problem all seems good. Next I noticed that the last connector on the combination unit go's into the "spiral cable" (round thing). I removed the four screws and looked this device over carefully................It's completely made of plastic???? OK, again the horn relay wire (GRN/BLK) go's into this unit and there's no metal anywhere on it for the circuit to touch the steering wheel to complete the steering wheel circut to ground. Please, I'm I missing or don't understand something here? Thank you all very much. Jim

[MR-355-5sfTe]

has the car been in an accident? it's possible that they repaced the wheel\airbag and left something out..... sorry for the lack of proper info on this, I replaced my horn and steering wheel immediately after purchasing the car.....

[johnr]

Sorry, don't have a Sensor for ya. When I bought the vehicle I did a check on the VIN and insurance....No accidents as listed/known. Perhaps something is missing as I'm not sure becouse I've never seen one apart before. I do have some good parts diagrams and information, however their just not broken down to the detail I require. I have also exhasted myself on the WEB for info. Toyota's parts people won't give me the time over the phone (just the bring it in attitude $$$) If ya here of anything please reply, Thanks for your input.

[MR-355-5sfTe]

do you have a FSM (factory service manual) ? if not, I'll check mine once I get off of work, and try to scan the info.... if all else fails, you could simply install a push-button switch. I have a Fiam three trumpet "euro" style horn installed and wired to my 355 steering wheel....


you could possibly take a bit of aluminum foil and try to make a contact plate.. .in that piece that you said was "all plastic"..... most aftermarket wheels\adaptors come with a plastic disk that slips over the column...the contact side is covered with aluminum foil... which allows the current to pass through when it touches the live portion.... sorry if this isn't helping, I'm not much of the electrical expert around here....
I'll check my manual and see what I find.

[jtl]

the horn on my 91 na didn't work either when I bought it used. I haven't looked at it yet but I wonder if it had anything to do with a recall on this vehicle for the steering wheel airbag. I know that the recall was done and the installation was modified on my car before I got it. I wonder if they left something out or screwed up the reinstallation. Just wondering if you had this recall done as well and maybe they screwed it up (ie. left out a part).

[johnr]

Thanks again guys, For (jtl) any recalls done are unknown, I don't have a paper trail), however I'm sure "our" horns worked at one time even if they were changed/updated. By law any mods/change would still require a horn circuit to work correctly.

For (MR-355-5sfte) I was thinking about putting a button horn in but decided to investigate the cause. Now I'm just fustrated and determend, (darn 2s). I'm not to sure about the tin foil idea due to any chance of grounded shorts setting off the airbag. (It would more then likely happen to me) It's almost like, pushing on the horn, everyone around looks as the airbag inflats in thee chops... I'm thinking..as you said yesterday, somethings missing or this Spiral Cable works different then what my mind phyics allow. I don't have a manual thats detailed indepth. All that I know is that the relay ground wire go's into the spiral cable and nothing comes out for the steering wheel to get grounded by. Infact the steering wheel itself sits in the center of the Spiral cable on a rubber/plastic gasket. PS Thanks for looking into your book.