What is the little electronic device for ?

General Discussion about the Datsun PL510
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What is the little electronic device for ?

Post by andrew.lori » 02 Jan 2017 17:27

I have a couple instrument assemblies and I just discovered there is a difference with the Speedos???
If you look at the picture you will see a little electronic box added to one of the speedos and it is OEM.
What the heck is it for.
I plan to list both assemblies in the classified but would like to know what this is before I list.
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1966 Sunbeam Tiger MK1A
1970 Datsun 510 KA24DE Street car
1970 Datsun 510 CASC Road Racer Sold)
1972 Datsun 510 SR Monster Sold it
1977 Datsun 200SX Sold :(
1973 Toyota Celica
1972 Triumph GT6 SCCA Vintage Race Car / Money Pit

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Re: What is the little electronic device for ?

Post by RMS » 02 Jan 2017 18:03

must be a 73 thing? I have a stack of clusters and not one has that box.
two_68_510s wrote:I guess our donkeys are quicker then your sled dogs!

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Re: What is the little electronic device for ?

Post by bertvorgon » 02 Jan 2017 18:44

If I can contort myself enough to look up under my dash, I will take a look and see if there is one on mine...I do not remember.
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

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1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
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Re: What is the little electronic device for ?

Post by datzenmike » 02 Jan 2017 20:59

The rusty box? I think it's a speed switch probably for emissions. Notice that one speedo stops or starts at 10 MPH and the other at Zero? My B-210 had something like this. When the needle touches the 10MPH it opens a switch I think.

On deceleration my B-210 had a very slight fast idle. As you slow in first gear the speedometer touched 10MPH the engine would lurch down to it's set idle speed. Perhaps a rudimentary BCDD to lower emissions.
"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs

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