StoneGrey

I need help locating the IC "chip" on the board
directly behind the speedometer module. The chip
runs the speedometer and odometer. The output of
the odometer side of the chip is not working for my car. The chip is ITT UAF 2115, I've heard that a UAF 1025 is a direct replacement, but can't find or purchase it. Any help out there?

Thanks,
Tom
86 944
88 951S
91 C2 Targa

tifosiman

</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by TurboTom:
<strong>I need help locating the IC "chip" on the board
directly behind the speedometer module. The chip
runs the speedometer and odometer. The output of
the odometer side of the chip is not working for my car. The chip is ITT UAF 2115, I've heard that a UAF 1025 is a direct replacement, but can't find or purchase it. Any help out there?

Thanks,
Tom
86 944
88 951S
91 C2 Targa</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Are you certain that you don't have a stripped out plastic gear in the speedometer assembly? That is the usual suspect when the odo stops working but the speedo still works. You can get a replacement from <a href="http://www.KLAIndustries.net" target="_blank">www.KLAIndustries.net</a> . That's where I bought mine from and the install was fairly straight-forward....

Tifo

StoneGrey

Tifo,
Thanks for the reply, but the plastic gears are fine, I need the IC chip that drives the odometer motor. I checked it with an osilloscope and the chip is at fault. I can drive the motor with a signal generator and the odometer works. I just need to find out where to purchase this IC.

Tom
86 944
88 951S
91 C2 Targa

James86-951

There is a place here in Atlanta called Speedometer Exchange. They do all types of speedo repair on the dealership level. They are very good and will repair for the general public as well. (The local (only) Porsche dealership in Atlanta uses them too.)

william_b_noble

contact sales@odometergears.com - they have it for $25

william_b_noble

replaced the chip and a 33 ohm resistor, that got one speedometer working. I had another one where the speedometer worked but the odometer didn't - I found a fragment of the old disintegrated gear and took it out, made a little 555 chip oscilator and have been running the unit at about 150 MPH for an hour - so far it's working fine and the odometer is counting, so I think I've now repaired two units - whoopeee.

I have one chip left, so if you need it, contact me - I can let the spare go for $20 - I got it in case the second speedo needed a chip, but it was a mechanical issue.

nofalls

555 ocillator is how I roughly tuned my speedo to the new tire size. I replaced one tailor resistor with a trim pot and fine tuned to a GPS. The speedo is now about dead nuts up to 85 which is my personal limit on American highways. Problem is the odo runs a little fast. I need to figure out which resistor is the tailor for the stepper motor and add a trim pot to that.

Sentinelist

I smell a write-up on how to do this.

nofalls

I could do a write up but to be honest I stole, uh learned, most of this from the 911 board. R2 is the tailor resistor.

CVDH

Which gear should I need for an '84 944?

flagtie

CVDH: For an early dash, I would open it first. It's very likely just a gear slippage problem.

https://www.youtube.com/watch?v=HNhvFl9nPrE

CVDH

Cool, I'll have to give that a try. I'm ordering a new dash and gauge cluster trim anyways, so I might as well have a look-see.