My mom's 79 240D Hazard Switch Relay is acting up which in turn is affecting the turn signals. If she's signalling to turn, the turn signals will flash for about 8-10 times then stop. To get it going again, the hazard switch is turned on and turned off quickly. Then the turn signal will work again for another 8-10 times.

I'm assuming the Hazard Switch Relay is bad because when I pound on the hazard switch (from frustration) the turn signal will work intermittently. Maybe the relay is bad? What do you guys think?

Does anyone here have a spare on hand that they'd be willing to sell my mom inexpensively?


jrmd01@yahoo.com

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JR
1986 Gold 300E 4Dr automatic

Dang, there were two at the junkyard a couple weeks ago. Had one in my hand but didn't get it because I didn't need it. I'll let you know if I go back anytime soon.

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Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References

Mine has been doing that for the past few months, ever since I got a new hazard switch. For a while after it started acting up it began working perfectly again, but then all of a sudden the turn signals would blink on both sides (as if I'd pressed the hazard button) regardless of which direction I was trying to signal.

Replacing the hazard switch (again) fixed that, but now recently it's begun acting up again! I think it may not be the switch/relay itself, but it's connection. The newer ones I've gotten just don't seem to snap into the wire socket as tightly as the original one did.

Its also possibly a short or something in the wiring - the reason I had to replace my original switch in the first place is some soda was spilled on it (not me!) and it shorted out... It's possible there's still some sticky goo in the socket or something. I intend to open it up and look at it at some point, but I haven't had time...

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'81 300TD Wagon 355k (Miss Diesel)
'83 300SD 180k
'84 500SEL 190k (Parting it out)

Hazard relay....same symptoms mine exhibited before I bit the bullet and purchased a new one (about $30). It's located under the wood console.

Good luck!

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1976 240D
1987 560SL
2007 E320 Bluetec
1998 C280 (now son’s car)
1982 240D Manual - Sold

I'd be willing to bet it's the switch. I have the same problem on my '85 300D from time to time. When it acts up, as in not work at all, I'll flip the turn signal stalk to either direction and then I'll just jiggle the hazard switch a bit until the turn signal begins working. It'll work fine for a while. This more than anything proves that its the switch.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

It is pretty obvious from the posts that operation of this system is greatly affected by switch/contact conditions. Before I replaced the hazard relay, I noted that moving switches back and forth sometimes provoked it to work...sometimes for a day...sometimes only until I put on the turn signal at the next turn. After finally taking the console apart and getting access to the relay, I noted that holding the relay in certain positions encouraged it to work better. I tried bending the socket holes with pliers and that actually got it working for a short time, but it eventually began to act up again, and so I replaced it.

That said, I believe that a weak relay may be helped to work better by changing worn switches, changing switch positions, bending sockets, etc. But in my case, the root of the problem was the relay.

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1976 240D
1987 560SL
2007 E320 Bluetec
1998 C280 (now son’s car)
1982 240D Manual - Sold