Sppedometer stopped working in my 1990 saab 9000 s 5 speed how do i fix it

its possible the valve at the end of the vacuum hose where it enter,s the booster i s faulty, otherwise the booster is leaking

replace the contact in the steering wheel horn pad to repair

will need to remove heater core and replace.

Maybe the anti lock brake ecu is bad or the sensors need to be replaced on the appropriate wheel as indicated by fault codes for the ABS system.

Fault codes were not provided on the original 1989 model of the Saab 9000, but the 1990 to 1991 model ecu can be installed and fault codes read from the AntiLock warning lIght flashing codes.

Check wiring to ensure there are no opens to the module from the ABS Wheel Speed Sensors.

Maybe check that the wheel speed sensor is picking up a sinusoidal wave of AC electricity when the wheel is spun as seen on an oscilloscope function of a multimeter. This would isolate the problem to wiring or the ECU being at fault.

The commmon thing is GROUND.
Probably the ground strap from the engine to the chassis is worn, broken, loose, corroded, or otherwise not making good ground.
Check the negative cable on the battery to see if the "pigtail" is disconnected.

Replace or install a ground strap from the engine to the chassis.

Do that first; otherwise, on the positive side, the inline 100Amp FuseLink may be blown.

Hope this helps!

is there power and ground at the fan connector? 2 pin at back of fan housing. ck with volt meter or test light.

The valve is stuck.

If you can't get from previous owver, then dealer is only way to get code. Should cost around $100.

Check the battery, alternator, and fuel pump.  More than likely it will be one of those three.

hey

Is it the fan belt your after??
http://www.toronto-short-rental.com/images/Serp_belt2.jpg

Damien