pietrzj
Well-known member
- Joined
- 19 Mar 2014
- Messages
- 309
All,
I had the warning light come on recently. Not on all the time, just occasionally and more frequently this last week. I changed the belt a year or two ago and visually it was fine, but looked fine when I checked it this week other than a bit slacker than 5mm so I took a shim out. No change the the warning light so I dug deeper.
The switch itself is not a sealed unit and is only held on with one alan stud, so was easy to remove and strip down.
It was then obvious that it could not have been triggering due to a slack belt as the cam travel of the switch really only activates over large distances i.e when the belt has snapped.
I tested the resistance across the two pins and found it was not a clean closed circuit. The resistance was varying from 10s of ohms to 0.1 ohm. So the fault was within the microswitch itself.
I carefully removed the microswitch and cable assembly by scraping to top of the two plastic pins and sliding it up and out.
I then cleaned the whole unit up and, using contact cleaner, soaked the switch such that the tiny pin actuator was submersed as I operated it manually to ensure the contact cleaner got right inside.
I left it submersed in the cleaner (using the lid as a container), over night and dried it off in the morning. The resistance was now a solid change between 0.1ohm and infinity when operating the switch - Fixed!!!
Reassembly was straight forward and for good measure I greased up the bearings in the plastic wheel.
The saved me £77 + VAT for a replacement part, so well chuffed.
Really easy fix, so if you get something similar and its not a missing fan belt. Give it a go.
Hopefully the photos will help...
I had the warning light come on recently. Not on all the time, just occasionally and more frequently this last week. I changed the belt a year or two ago and visually it was fine, but looked fine when I checked it this week other than a bit slacker than 5mm so I took a shim out. No change the the warning light so I dug deeper.
The switch itself is not a sealed unit and is only held on with one alan stud, so was easy to remove and strip down.
It was then obvious that it could not have been triggering due to a slack belt as the cam travel of the switch really only activates over large distances i.e when the belt has snapped.
I tested the resistance across the two pins and found it was not a clean closed circuit. The resistance was varying from 10s of ohms to 0.1 ohm. So the fault was within the microswitch itself.
I carefully removed the microswitch and cable assembly by scraping to top of the two plastic pins and sliding it up and out.
I then cleaned the whole unit up and, using contact cleaner, soaked the switch such that the tiny pin actuator was submersed as I operated it manually to ensure the contact cleaner got right inside.
I left it submersed in the cleaner (using the lid as a container), over night and dried it off in the morning. The resistance was now a solid change between 0.1ohm and infinity when operating the switch - Fixed!!!
Reassembly was straight forward and for good measure I greased up the bearings in the plastic wheel.
The saved me £77 + VAT for a replacement part, so well chuffed.
Really easy fix, so if you get something similar and its not a missing fan belt. Give it a go.
Hopefully the photos will help...