Hazard warning lights half working?

1987 Cabriolet 1.8 Carb.

The cabrio is due for it's MOT so I have been giving it a quick once over. Everything seems OK apart from a weird thing with the hazards.

When activated only the 3 passenger side lights work (bumper, wing, rear cluster) all three on the drivers side don't flash, remaining off.

When using the indicator stalk to indicate right (drivers side) the 3 lights work perfectly, as do the passengers side when indicating left. The tell-tale in the hazard switch flashes and it doesn't flash the drivers side with or without the the engine running.

It's only done a few hundred miles since last year  and I havn't touched anything on the electrics or done any other work for that matter since the last MOT which it passed with no advisories.

Any ideas what the problem is and how to fix it???

Usually the hazard switch or terminals to the switch. Have you got a spare? You could pop it apart and clean the contacts inside the switch as long you know how to put it back together 😂

Disconnect the battery if messing with the hazard switch as it's always got power going to it.

I also recon the switch may be at fault.

From the above and that the same relay is used for both  hazards and indicators, the indicators worked so it was likely to be the switch playing up.

I flicked the switch on and off a few times and that seemed to get it to work 9 times out of 10. Life has taught me that when Mr MOT man does it it will be 10th and not work. So I disconnected the battery, extracted the switch, very carefully pulled it apart and cleaned up all the contacts, inside and outside.

et voilà ! further proof that lack of use is no good for cars, even those that spend most of their life tucked up in a warm dry garage.

I think it would of happened anyway, I mean how often do you people use their hazards anyway? Nice to see you took the effort to clean the switch , most people would just buy a new one. Well done sir!

Ever since I had a mk2 polo I've carried a spare hazard switch as they always seem flaky - like you say, especially when the MOT man touches it!