Under Dash Passenger side to the right of the kick panel
In the 1989 Volvo 740 GL with a Bosch system it is located just above the steering column on the dash.
Probably a bad ignition control module..Autozone for $105-$160..
there is no part called an "ignition controller". one part is called the ignition control module or "power stage" which is on the left side inside fender wall partially hidden by the air cleaner, the other part is called the ecu, electronic control unit or computer and it is under the dash above the accelerator pedal.
The ignition amplifier module or power stage is bolted to the left front inner fender near the battery.
The single spark you get is when the ignition control module reacts to the key being turned to or from the start position. My first thought is to check the distributor module and the wiring (known to deteriorate) that runs under the engine from the distributor to the ignition control unit. Also have a look at the ballast resistor located near the coil for a loose wire or corroded connector.
pop the hood look behind the air filter assambly, driver's side
What year and model
in the upper control module
In a Volvo 850, the fan speed control module is typically located behind the glove compartment. To access it, you may need to remove the glove compartment and its support bracket. The module is usually mounted on the blower motor housing or nearby, depending on the specific model year. Always consult the vehicle's service manual for detailed instructions and safety precautions.
On my 90 740gl it is right next to the ignition coil. It depends on the ignition system used. On a Regina ignition, I think everything is built in the coil (The big square one) The regular round coil is for BOSCH ignition and a separate module is use. NOT SURE, would appreciate confirmation.
On most models it is mounted in the center of the dash under the main fuse panel which is located under where the cb sets. At least that is where it is in my truck.