Page 1 of 1

safety switch failure

PostPosted: Thu May 18, 2017 6:20 pm
by bob_rich
Hi Folks

went to take the +2 out last Saturday and it appeared the battery was totally dead. Quick check with a DVM and the battery was fine at 12.4V. The car has a battery safety switch that I set to off every time I leave the car. further checks with the DVM showed that the volts drop across the switch was the full 12.4V irrespective of what position it was in. Ordered a new switch on line and it arrive Monday installed it and all appeared to be fine again.

decided to open up the old switch by drilling out the brass eyelets that hold it together. Pictures of the switch type (it is a common type sold by numerous vendors) and the parts after the strip down are attached below

Clearly there is no damage to the contacts (starter current does not flow through the switch) and the switch was bolted to a flat surface in the drivers footwell. Only thing I can think is that the plastic inner surfaces had worn or maybe plastic parts jammed and so engagement was just short of the required movement for contact. I reassembled the switch using M4 bolt sets with large washers and a check with a resistance meter suggest that it is now OK.

Thought I would relate this story as others may have had this problem. Or be caught out if it occurs. If it happens again i will try a "firm tap " to see if the unjam it.

Bob