Post by stilllearning6 on Mar 15, 2005 16:17:37 GMT -5
1977 Celica - horn would not sound unless wheel was turned to an extreme position .
Pulled steering wheel to expose horn wiring / horn contact rings .
There are two contact rings seen from the underside of the pulled steering wheel .
One ring is brass and appears to receive 12v from a brass contact lead that is seen protruding from the steering column . This contact lead was measured to be always hot (12v juice ) and I believe that it feeds the horn circuit .
The brass contact feed terminal lead touches the backing plate brass ring of the steering wheel . Thus , the steering wheel appears to receive 12v .
It is my guess that the brass ring then feeds the 12v juice to each of the left and right side black wires which in turn feeds into the left side horn pad and the right side horn pad. I could get 12v at each left and right side horn pad contact switch plates before I started disassembly only if I turned wheel to exterme left or extreme right and horn would sound by itself .
The second contact ring (as seen from the underside of the steering wheel) appears to be steel and it is my guess that this is the " return to ground " steering wheel terminal piece as it fits over the steering column splines when the steering wheel is replaced .
Can anyone confirm / correct the above theory ?
Now a dilemma / concern -- with the steering wheel in the kitchen , I get zero resistance using an ohmmeter as I touch one probe end of the ohmmmeter to the brass ring and the other probe end of the ohmmeter to the steel ring . It was my expectation to get infinite resisance .
I felt that the circuit would be complete only when the horn pad switch plate gets depressed . Any feedback ? Is this an internal short inside the steering wheel ?
Pulled steering wheel to expose horn wiring / horn contact rings .
There are two contact rings seen from the underside of the pulled steering wheel .
One ring is brass and appears to receive 12v from a brass contact lead that is seen protruding from the steering column . This contact lead was measured to be always hot (12v juice ) and I believe that it feeds the horn circuit .
The brass contact feed terminal lead touches the backing plate brass ring of the steering wheel . Thus , the steering wheel appears to receive 12v .
It is my guess that the brass ring then feeds the 12v juice to each of the left and right side black wires which in turn feeds into the left side horn pad and the right side horn pad. I could get 12v at each left and right side horn pad contact switch plates before I started disassembly only if I turned wheel to exterme left or extreme right and horn would sound by itself .
The second contact ring (as seen from the underside of the steering wheel) appears to be steel and it is my guess that this is the " return to ground " steering wheel terminal piece as it fits over the steering column splines when the steering wheel is replaced .
Can anyone confirm / correct the above theory ?
Now a dilemma / concern -- with the steering wheel in the kitchen , I get zero resistance using an ohmmeter as I touch one probe end of the ohmmmeter to the brass ring and the other probe end of the ohmmeter to the steel ring . It was my expectation to get infinite resisance .
I felt that the circuit would be complete only when the horn pad switch plate gets depressed . Any feedback ? Is this an internal short inside the steering wheel ?
