RWD - 1991-92 Speedo - Technical Question for Art Benstein

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1991-92 Speedo - Technical Question for Art Benstein 900

Hi Spook,

Dried out = leaked. Difference in being observable is in the rate of leakage.

The electrolytic caps I saw in these Yazaki speedometers appeared to me to be as generic to electronics as 16p nails were in the construction of our North American stick-built homes before the advent of pneumatic nail guns. I did read Amarin's guess that they might be high-temp caps for the automotive environment -- that's currently a hot topic (!) in the dash cam reviews, and I understand the conclusion made that maybe Yazaki should have looked to aerospace parts back in the 90's. All of the new electrolytic capacitors I have in little plastic drawers are 105C rated as were those Nichicon SR found in the 91-92 Yazaki gauges. To me, 105C is standard, not 85C.

My interpretation of your questions, for the practical end, is you want to know if you might fix the speedometer by replacing capacitors. You've read of the "capacitor plague" but aren't interested in the common approach to just replace them all. To that end, I can't help.

The caps themselves would not be my first suspects. I'd look to see the gauge "motor" windings were electrically continuous to the driving pins on the chip. Examining the schematic, I'm not able to rule out that one or more caps being replaced would suddenly bring the speed needle back to life. No experience, and no documentation on the custom chips. Sorry. If you're not in a hurry, you could get it checked out the same way you did with the 93/94 unit.

Art Benstein near Baltimore

"The absence of evidence is not evidence of absence"


New 1991-92 Speedo - Technical Question for Art Benstein [900]
posted by  spook  on Mon Feb 18 02:47 CST 2019 >

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