As a follow up for future searches where someone might be looking for this part.

For the 89 300SE W126, the Combination Relay (which handles the hazard and turn signal flashers along with a lot of other things) is the large B Relay in the fuse box and can be had at Fastlane.

Fastlane part number P2020-32725 and cost is $70.37
MB Part number 201 821 0047

I think the first task should always be to check out the Hazard Switch for connection or failure but it seems in my case with the erratic working of the signals where sometimes they work sometimes they don't it has turned out to be the relay.

When I get the part I will know for sure and report back here.

Thanks again

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1989 300SE 155k
1998 HD Road King/Iron Butt Member)
2006 Nike Air Max Moto