does anyone have the schematic for the speedo from a '92 240 (I believe '91-93 all used the same model). This is an electronic speedo, not a mechanical one.

If not, how about at least a pinout?

Thanks in advance,
Chris

Schematic? I started to make one a couple months ago, I think. Before I go digging and scanning, tell the nature of your curiosity. That way I can make sure what I have might be satisfactory.
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Art Benstein near Baltimore

Art --

I was very glad to see your schematic online. I copied it for future reference. Cah you suggest a source for the UAF 2115 IC? Lack of a diode or any protection lets this thing fry when the wrong wires are connected to the cruise control spade on the back of the cluster. We just bought one this way, and I need to fix it.

By the way, I found a .PDF from ITT describing this chip and giving all the parameters. I could send you the file or the URL if you want it.

I made a simple test stand for the instrument, using the pickup coil and a 12 v power supply. Putting the coil next to a solder gun or other transformer gives a 60 HZ signal.

Regards, Chuck Yarter

Hi Chuck,
I recall looking for the sheet on that chip; finding ITT's old site in Europe and someone had a note it was replaced by or similar to another number that had info available. I'd be glad to look at the sheet. In return I can dig up a chip my next trip to the boneyard- they are plentiful and easy to find, as someone goes through the cars and removes the board to grab the odometer gear.
My bet is that is the best source for the chip. I like your theory on its failure cause. I thought most of the dead speedos reported after reinstalling the cluster were due to that flex circuit fuse not getting properly screwed down. Feel welcome to send email.
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Art Benstein near Baltimore

Art, I really need the UAF2115 chip if you have an extra one to sell. I took one out of my 87 to replace my wife's chip in her 90 240 to get the odometer working again. Now I need the chip for my 240! I'm at rdmegargle@yahoo.com
Thanks -- Russ in Brighton, MI

No problem, Russ, it should be just as easy to find two as one, in case Chuck returns. I'll send you an email when I have it.
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Art Benstein near Baltimore

......
Schematic? I started to make one a couple months ago, I think. Before I go digging and scanning, tell the nature of your curiosity. That way I can make sure what I have might be satisfactory.
......

Thanks for the reply Art. Basically, my odo stopped working a year and a half or so ago, and I want to fix it. I need the schematic so I can setup a bench test harness for it.

[I've had the speedo out on several occasions, disassemble it inclusing the two side PC boards that unscrew from the main head, reassemble, and it works for a bit. I don't think it's a stripped gear, since I've examined them all several times under magnification, and there are no cracks. I have ordered a replacement gear for $25, and am awaiting it's arrival.]


Chris
1992 244 somewhere aronund 240K km

Chris,

My notes are done from a 91 but the schematic was made from an 89. I think the parts layout is different, but the circuit is the same or very close. Problem: I have no idea how the KPH speedo you have compares to the K10042 MPH speedo.

Hope this helps.

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