Hi,

After my first and only speedometer issue in a 240 about 5 years ago, I became aware of the value of the cluster boxes. I was able to resolve my problem without expense thanks to the board, but I've been keeping my eyes open and put words out to where I now have 8 boxes on a shelf in my shop. There's been a lot of 240's around here that have gone to scrap in the last couple of years.

Two speedos are mechanical and one's a 4 pinner, but I decided this past summer to cycle the rest of the boxes through my 91 non ABS to get an idea of what condition they're in. I know the speed sensor output to the ECU may not work, but I think the speedo, odo, lights and gauges should.

The first two needed gears and a few lights which I replaced, but the third one has me stumped. It's wearing 87-240 in marker on the back and it's speedo drops to zero repeatedly and often. The slightest tap on the dash brings it back to speed almost every time.

I expected to find a fault in the L connection or the speedo pins so I hooked it up using the Benstein Nobel Worthy Troubleshooter.



I found it very amusing to sit in my car with a cup of coffee, motor off, and the speedo and odo counting away. My first thought was " I've got to find a job where I get paid by the mile." That's brilliant, Art.

I composed myself and let it run 10 miles and no amount of banging, twisting, or shaking could make it fail. I'd retensioned the L before the experiment so I presumed that was the problem, but after 2 days of flawless operation it resumed it's bad habit. Since then I've had it in and out twice and gone over the power lines from the L to the PCB and all seems well. I've also reflowed the motor connections on the board and verified the car's circuits by replacing it's original box. It works fine.

I'll keep at it. I've never had the face or needle off of one of these and wonder if there's something there I should look at. I see how the motor on the PCB drives the gears for the odo but it's unclear to me what makes the speedo needle move. Any ideas would be appreciated.

I don't know if it's relevant or not, but of the hundred or so times the speedo needle has dropped to zero, on two occasions at 50 MPH it as dropped to around half speed. Again a light tap brings it back.

Regards. Peter