I used IPD’s jumper to fix the non-functioning temperature gauge in my 1986 240 wagon. It has the tachometer upgrade (instead of the clock). But when I put it back together, I get:
- no dash warning lights
- shift indicator light comes on
- when started, the alternator light comes on
- speedometer doesn’t work
- temperature gauge still doesn’t work.

I connected the jumper to #1 and #3 pins and they are tight. I’ve cleaned all contacts and made sure the three-pin connector on the circuit board inside the speedometer is tight and connected. My guess is that I got the two wires on the back of the tachometer backward. Looking at the back of the instrument cluster, should the red/white wire be on the left terminal of the tach (passenger side of the car)? Any help or ideas greatly appreciated.