One thing that annoys me is that the intermittent wipers are sometimes too fast. I hate having to rotate the switch on and off. Anyone ever added a micro switch to the steering wheel that would operate the wipers once?

My '83 TD does that already... flick the switch on/off and it does one wipe. Doesn't really solve the problem though, which is not having a longer interval.

The 220D/8 had a foot operated switch/pump to operate the windshield washer system. The beauty of it was if you carefully pushed the pedal to only operate the wipers, you did not get the washers as well. Worked quite nicely as an intermittent wiper switch even though it was only a one-shot, because there was nothing else back then!!

So although the above is not an available solution, it certainly says your idea should work fine.

__________________
1961 190Db retired
1968 220D/8 325,000
1983 300D 164,150

You can develop the dexterity to bump the washer for 2-3 wipes without triggering the pump.

Or work this into the wiper circuit -

http://www.jcwhitney.com/autoparts/Product/Pr-p_Product.CATENTRY_ID:2004484/c-10101/Nty-1/p-2004484/Ntx-mode+matchallpartial/N-10101/tf-Browse/s-10101/Ntk-AllTextSearchGroup?Ntt=wiper

Sixto
87 300D

No need. Contact techguy512.
He sells a drop-in replacement for the wiper relay that adds a programmable wiper delay that can be set anything from 3-30 seconds.

I've been using it for several months and I don't know how I ever lived without it.

FI, how did you work the adjustment know into the dash or console? On a later 123, can you retrofit an idle adjustment knob?

Sixto
87 300D

Its a drop-in replacement for the factory relay.

Remove the driver knee panel, reach up behind the cluster and swap the relays. Takes all of 5 minutes.

Guide.

Attached Thumbnails

     

That looks nice, how much was it?

I don't know why Mercedes didn't put variable speed wipers in these cars, heck even my '86 ford has them.

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

Using the wiper switch to set the delay is brilliant... and I've gotten it through my head

I still wonder if there ought to be a distinct knob to set the delay because it will be a challenge to explain the process to others who drive my car. Maybe simpler to put a cutout switch to revert to factory 4 sec delay or at least disable the adjustment feature.

Sixto
87 300D

I recall it cost about $35 + core. Just a little more than his tach amp upgrade.

At first I was wanting a rotary knob to select the time delay too, but in the end this system works very nicely. Once its used a few times it becomes second nature.

Techguy512 is one sharp forum member. He is also the one who has built the tach amps.
I hope he is nestled away somewhere pouring over the operations of the cruise amps.......

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

Then maybe the climate control.

Can he fix Windows Vista?

Sixto
87 300D

VWs had a similar wiper relay in them from 93 to 97, I added one to my 91, and was going to work out how I could wire one into the SDL... and now I don't have to! Thanks for the link!

-Jason

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.