94 JETTA - electrical help needed!!

[arsoud]

Have a 94 Jetta with an automatic that has a few electrical problems.
The speedometer doesnt work . ( the trans speed sensor was replaced) .
The tachometer , horn and cigarette lighter dont work either . Have not found a bad fuse yet . Any good help would be appreciated .
Could the ECM be the problem or the speedo head unit? Thanks in advance
Al

[peppi]

I don't think these 4 are related. You can diagnose 2 (horn, cigarette) easily, disassemble everything, find + wires and go towards the horn or see if there is any + voltage at cigarette lighter. About speedo+tach, try to detect variable +5V and 0V at the gauge cluster, when you move your car slowly (or someone rotates the sensor at transmission). you must have the electricity in the system, so be very careful what you doing. If you detect changing +5V, your dash board is defective. If not, you must have a short somewhere between speedo sensor and dashb. Assume speedo sensor is OK, if it's been replaced. But check fuses again.