Hiya H2oman,

A fine Volvo 240 year: 1979. I had two in prior decades. A 245 and a 242.

The 1976-1979 wiring diagrams in my 1997 final imprint (unless they've published newer editions) Haynes 240 Repair Manual shows shows:
- black wire is +12VDC from fuse #1 (8 AMP, factory).
- The grey, what may appear as white, wire, is negative ground.

Key position #0 is the key, inserted in the ignition, yet not turned.

See Art's animated GIF here!:



The power antennae is also power at the #1 fuse. Insert the ignition key and turn the key to position 1, the accessory position, to deliver power to fuses 1 through 3.

So, you'll need the key in the ignition, turned to position #1, the same position the blower fan will blow when the fan switch is turned on, and the wipers work

Key position #2 turns on the dash lights and is the same as engine run after starting the engine.

You'll also want to look here:
http://www.volvowiringdiagrams.com/?dir=volvo/240%20Wiring%20Diagrams

The PDF file:
TP30057-1 1980 240 260 Wiring Diagrams.pdf

PDF Page 5 for the fuse box. Radio and power antenna on fuse #1.

Radio circuit is on PDF pages 125-126.

Yet this 1980 wiring diagram, on PDF pages 125-126 shows the power antennae powered at fuse 8.

This 1980 info may more or less be a match. May be able to find a scanned in or drawn 1979 Volvo 240 / 260 wiring diagram.

Though if the factory radio was replaced with after-market, who knows how a prior owner or stereo installer service altered the factory harness. Or merely overlaid the factory harness with after market wiring for power, ground, power aerial, and speaker out.

A modern car stereo head unit with built in power out will have two channel stereo to front and rear speakers.

You could cut a hole in the rear door through the inner door card vinyl cover and pressed fiber material. You may or may not want to do that.

You do have option, for the somewhat rare Volvo 240 (240 wagon) C-pillar speaker option. Perhaps your 1979 Volvo 245 coms fitted with these. You do not mention.

Volvo 245 factory C-Pillar void (speaker hole?) covers:



Volvo 245 factory C-Pillar speaker-equipped covers:

245 right side, as you sit on the seat.


245 left side, as you sit on the seat.


The factory C-pillar 245 speaker-equipped covers come with a (I guess) Dynaudio speaker. You may be able to fit a quality 3.5" or 4" (? or so) speaker to replace the aged factory pre-mounted speaker.

Though to cut through the vinyl and fiber board of the factory C-pillar cover not fitted with speaker may result in their destruction unless you are well practiced in working with such material and center the speaker mount to fit the C-pillar mount.

The void in the C-pillar is not large, like a front or rear door, so resonance is not great, yet delivers audio depth that may bring more enjoyment as you play your tunes or hands free blue tooth while hands free motoring.

If you can find the C-pillar speaker mounts as I have in my 1990 245 picture here, like on ebay or somewheres, a salvage yard, perhaps, after market speaker is not so hard as you drill out the factory rivets securing the factory speaker.

Questions?

Hope that helps.

Perpetually Itchy MacDuff.
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