Ignition switch issues.
Posted: Mon Dec 27, 2021 9:21 pm
Hi Guys,
On testing the Hahn ignition switch for correct wiring, I found that the start position was dead...
Stripped the housing from the steering wheel shaft and found it to be a 1979 Jan switch cluster.
This means there is no hole to remove the tumbler part of the ignition, so I removed the switch part
This I found to be cracked and very brittle, so we ordered a replacement.
On installing the new switch block and testing the leads, we found that the start position was still dead.
Removed the switch block and tested it with a screw driver and found it worked.
SO.. that means that the key tumbler part was at fault.
With no means of pushing the location spring to release it from the housing, I had to remember where the hole was on the MeFusco assembly.
As i was relying on a old Toppy memory, we still managed to drill the hole in the correct place, thank goodness.
When I removed the tumbler, we found no wear, no loose parts or play, so no sign of why she would not travel to the start position.
Confident in my diagnostic synopsis, I started removing surface on the stop block on the start side of the unit.
Having removed approx. 3 mm of surface, I reassembled the complete unit and tested it.
It worked.
now I was wondering, how could this happen, and opened the old switch part.
We found that the main sliding contact never reached the start contact.......
So this could have been worked on before and just left when not working.
O well its right now so that makes me glade to share this fix,
Thanks for looking.
Herman
On testing the Hahn ignition switch for correct wiring, I found that the start position was dead...
Stripped the housing from the steering wheel shaft and found it to be a 1979 Jan switch cluster.
This means there is no hole to remove the tumbler part of the ignition, so I removed the switch part
This I found to be cracked and very brittle, so we ordered a replacement.
On installing the new switch block and testing the leads, we found that the start position was still dead.
Removed the switch block and tested it with a screw driver and found it worked.
SO.. that means that the key tumbler part was at fault.
With no means of pushing the location spring to release it from the housing, I had to remember where the hole was on the MeFusco assembly.
As i was relying on a old Toppy memory, we still managed to drill the hole in the correct place, thank goodness.
When I removed the tumbler, we found no wear, no loose parts or play, so no sign of why she would not travel to the start position.
Confident in my diagnostic synopsis, I started removing surface on the stop block on the start side of the unit.
Having removed approx. 3 mm of surface, I reassembled the complete unit and tested it.
It worked.
now I was wondering, how could this happen, and opened the old switch part.
We found that the main sliding contact never reached the start contact.......
So this could have been worked on before and just left when not working.
O well its right now so that makes me glade to share this fix,
Thanks for looking.
Herman
Still arguing about that one ..... 