M104-AMG

iTrader: (8)

I'd like to replace the integrated-circuit (IC) on the tach.

It is a Mitsubishi/Panasonic AN8352UBK (DIP-22) IC, and I have checked on Google, and can't find either a datasheet, nor any in stock, except in bulk of 300+ and most likely overseas.

Anyone have either a source, OR a datasheet on a AN8352UBK IC ?

Thanks,
:-) neil

DaleClark

iTrader: (55)

Good luck! I guess you're still tracking down the tach problem?

Remember, most of the components in the FD were sourced in the early '90s. Many may not be available any more, and others may be Japan-only parts.

I'd just get a used tach for cheap . Should be able to get a good one pretty cheap. If nothing else, it would help the troubleshooting.

Are you positive that the tach is getting the signal? No broken wires up to the tach?

Dale

M104-AMG

iTrader: (8)

I replaced the ignition coil wiring harness, which had worn insulation on the wires, but it didn't fix the jumping tach.

I looked at the Mazda wiring diagrams, and the flow shows that signales come from the CPU & Speedometer. Where is that ?

BTW: I found the IC. $50/each! $100/min.

:-( neil

saxyman990

A jumping tach is a common problem on FDs. 95% of the time, it is due to bad solder points on the back-side of the tach. This can usually be fixed by re-soldering the points.

-Rob

M104-AMG

iTrader: (8)

I already re-soldered all the joints/pads; installed new capacitors and diodes. The only thing I didn't change was the potentiometer and the integrated-circuit.

:-( neil

7-sins

The tach is controlled by the speedo, replace your speedo and you will solve the problem.

M104-AMG

iTrader: (8)

Even though my speed is working 100% ?

:-) neil

M104-AMG

iTrader: (8)

Yep, it was the speedo. Replaced speedo, and all is well.

:-) neil

DaleClark

iTrader: (55)

Interesting! Does the signal simply pass through the speedo to the tach or what?

Any more info on how that circuit works, Neil?

Dale