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MG Midget and Sprite Technical - strang hazard switch problem

i fitted a new hazard switch in my 1977 1500 a couple of months ago and it worked fine but today when i went to check my indicator lamps it now will not work, all is fine and indicators work but when you switch them on nothing.tried shorting out the 3 contact and the indicators all flash , when you check continuity on the switch terminals they show as working but when connect the switch back up the hazards don't flash . shorted the three terminals at the back with it plugged in and they work just wont work by the switch its got me scratching my head.
mark heyworth

If it works when shorting the three contacts, it can only be a duff switch.
Dave O'Neill 2

but has i said the switch tests fine when not connected
mark heyworth

Maybe it's just needing a bit of a workout, try flicking them on and off quickly about 10 ish times.
This works sometimes on older switches that haven't been used for ages, just cleans the contacts I guess, maybe your new one has a bit of grease or something increasing the contact resistance.
William Revit

I had a similar issue after fitting a new hazard switch on a 1500, the next time the car went out all the indicators failed, I ended up searching through the bin for the old hazard switch put that back on and all good again.
Tim Lynam

As Willy says, there may be contact resistance which could stop the flashers working. I'm guessing you checked the switch with a DMM (meter)? If so, you may get continuity on that but it only needs 2 or 3 ohms contact resistance and, assuming you have 21W flasher bulbs, then a current of several amps will cause a significant volt drop across the switch contacts.
Bill B

This thread was discussed between 15/06/2026 and 16/06/2026

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