You are stupid if you put a 30W fuse where it expects a 15W.
The meaning of the fuse is to protect the equipment in the network. If the fuse is not the weakest link any longer something else must collapse in case their is a highvoltage peak, a shortcut in the circuit or something else.
allows power distribution to the overdrive solenoid for overdrive engagement.
Behind glove box
Behind the ashtray--google "Volvo 940 overdrive relay" for detailed answers on how to get to it. It's beyond the fuse panel, the white one with black print on the right.
BEHIND THE ASHTRAY IN THE FUSEBOX, A WHITE RELAY STANDING STRAIGHT UP.
under the dash, driver side
it should be behind the ash tray in the fuse box that is located there.
Remove the fuse from the fuse box. Or remove the relay.
behind the glove In the relay/fuse panel behind the ashtray. After you remove the ashtray and holder you will need to remove the box above it to access the relay
Check either: Solenoid, Wiring, Switch, or OD Relay.
Try a known working relay in its place... I have also put my hand on the relay while someone is driving and pressed the over drive button on and off, you should feel the relay "click" inside.
Up through 87 the relay was located behind the ashtray behind the fuses. 88 and up, the relay panel is accessed from the passenger side panel on the side of the center concol. If earlier version, relay "I" - if behind side panel, relay "G".
Please go to this URL. I think 780 has the same relays and locations: http://www.davebarton.com/pdf/relay_87_700.pdf Igor.