Quote:
Originally Posted by Othen
Thank you Dave, all that is obvious, but I'm still not convinced it is the issue.
The solenoid (Bosch 033130203) is rated at 15A maximum and the momentary switch is only a few months old. I don't think it is gradually developing bad sectors, I think it probably had a manufacturing defect with one bad sector. That is my theory - I'm just going to monitor the issue, if it stays as it is now I'll suspect I'm right; If the MTBF becomes less I'll know it is failing and have to replace it, plus probably fit a relay at the same time.
Perhaps I should have explained Dave, that my reason for fitting a more substantial momentary switch isn't to handle more current (the one there should take 15A), but because that is what I happen to have in my auto spares box.
Alan
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From your description and my experience having diagnosed and repaired thousands in my time of similar faults, i'd say i was pretty near the cause of the problem Alan. Usually the switches are made with one "washer" attached to the actual button and then two smaller contacts in the base of the switch - as the button is pushed this "washer" bridges them out connecting the circuit.
The 15A rating on the solenoid is likely to be the holding current, the pull-in current will be about 2-3 times that figure and then you also have the inrush current on top of that. You will almost certainly find the pushbutton rated at 15A is for resistive loadds only, not inductive and if it has an inductive current rating, it's likely to be in the region of 6A continuous and no inrush current rating.
I also know from experience that the inrush current of the pull-in coil in the solenoid is in excess of 60A, the pull-in coil takes about 60A and then the hold-in is usually about 20-30A . Keep an eye on it and see what happens but i wouldn't mind betting you end up fitting a relay.
