Picked up a 1993 240 wagon a few years ago and noticed that the horns sounds muffled. When I run direct wires to each horn they have full LOUD tones.
It looked like someone was messing around with the wiring near the horns at some point, I have been trying to repair this and believe I have it back to factory specs.
The horns really aren't loud enough for real traffic situations. Has anyone encountered this or know whats wrong?

The two horn sort of high low factory horn tones are not very loud.

Very the grounds and consider a relay as your two other respondents recommend.

My suggestion is to add to the two factory horns. I collected low note Hella and Bosch horns from Mercedes and BMW from salvage yards. I have three or four horns. No relays yet the circuit does not protest the added current draw.

Also collect horn brackets to secure an additional horn yet ensure the horn does not touch anything so the horn resonates when you use it.

There is a 1992 Volvo green book system electrics manual on the Oz Volvo Archive. No positive battery post fuse panel like in your 1993.

Here are the Mitchell Service wiring diagrams in PDF files.

http://www.v8volvo.se/mekartips/volvo/index.html

Search the RWD page for other articles and suggestions on improving the not so loud factory 240 horn setup! The FAQ (Click FAQ) may have some suggestions also.

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Beh.

Check the voltage at the horns when they are live and muffled. Suspect bad earths.

Although I haven't dealt with this issue, more than likely it's at the horn contact ring at the steering wheel being carboned up, grungy or possibly worn creating resistance that is lowering power going through the horns. Do start by making sure the fuse with the horn (#2? from the top) isn't worn on the ends or corroded.

You could try pulling the steering wheel and cleaning it up, but it will likely never be quite as loud as what you just got hooking the horns up directly to the battery and chassis ground.

Note that unlike many cars, Volvo horns do not use a relay (leastwise the RWDs). A simple solution that doesn't involve pulling the steering wheel might be to splice in a cheap 12v relay just above the horns. There is fused 12 volts on the yellow? wire at one of the horns (a doubled connector with a yellow and black wire). You could cut that yellow wire and use the hot side as the 12V feed into a relay with the control side of the relay grounded out through the black wire that goes to the steering wheel (you will have to identify which of the two black wires and cut it) then connect the switched side of the relay to the other end of the cut yellow wire to the horn and connect the cut black wire (non-powered side of the horns) directly to ground. If you can find yourself a 240 wiring diagram and understand the rudiments of relays and maybe have a meter handy then it shouldn't be that hard to figure out which black wire to cut and how to hook the cut ends up to the relay and chassis ground.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

Horn contacts are dirty as Dave said. Not hard to clean them up. Just remove the neg battery cable before you monkey w the air bag.
Marty

Dave & Marty,
Thanks for the tip on the problem with my horns on the 245.
When it cools down outside I'll remove the battery cables and clean up those contacts with DeOxit and a Q-Tip.

Thanks! -Lame Duck

And put some Ox-Gard on the connections. Home Depot has it.