Please see the https://www.brickboard.com/FAQ/700-900/

The main FAQ files may list something on wipers. Look around.

Also, search the brickboard. You can use google or bing to target www.brickboard.com by adding to your search string (no quotes) "site:wwww.brickboard.com".

Your 1992 Volvo 700-series owner manual list wiper fluid reservoir and location.

I'm unsure where you'd find the windshield washer fluid reservoir. If not in the engine bay, somewheres under a panel in the cargo area.

The washer fluid pump motor can fail. The washer fluid pump may have a screen pick up that is clogged. May have to clean the reservoir. The rubber lines can sometimes come loose and leak at the end. The washer fluid can evaporate and washer fluid crystal form, can block the pump pick up or clog the lines.

You can check the fuses and electrics to verify full DC volts + (positive) reaches the washer fluid pump. Then check the ground.

More than one electrics problem occurs in that silly fuse and relay platform under the 700 and 900 series center bottom of the dash. Probably every 700 and 900 series Volvo owner may want to look at that assembly for failing electrics, overheated connection points, and such.

Usually, some will use a string needle or pin, kept in the Volvo someplace safely so you and others do not get pricked. Use the needle or pin on the washer fluid nozzle. Work in and out. You can dislodge blockages and also align the ball-shaped nozzle for proper aim.

Others brickboard members should chime in.

Hope that helps.

Carmex Jar.