It's a common fault: headlights and/or dash lights do not light when switch is in position 3, but the side and marker lights will light up in position 2. If the high beams will light up when the turn stalk is drawn against its return spring toward the driver, but lights go out when stalk is allowed to return to its rest position, then the high beam switch on the left fender mounted step relay (pins 81A and 66A) and the electromagnet are good. Otherwise, if the high beams fail to light up the step relay is faulty and should be replaced.
This condition is almost never caused by the headlight switch on '86 and later vehicles on which an upgraded switch was fitted. (First generation switches on 200 series vehicles from 1975 - 1985 were very failure prone after ten years of regular use).
Either the low beam switch on the step relay is faulty, or the main exterior lighting relay is faulty. To test the step relay, unscrew it from the fender (mounted behind the battery and beside the junction clock), disconnect the two connects from its lugs, apply power from the battery to pin 56 and ground pin 85. If the headlights come on, the step relay is good. Apply momentary power to pin 31B to verify the high beams are switched on then again to turn them off. (There is no need with this test to turn on the ignition circuit.) If all this tests good, the fault is in the main exterior lighting circuit between the headlight switch and the step relay.
On all late model 240s ('86 - 93), a relay for external lighting was interposed between the headlight switch and the fender mounted step relay. It's a general purpose SPST (single pole, single throw) with two outputs, a yellow (pin 87) to the step relay for the headlights and the white wire (pin 87A) to fuse 15 for the running lights (front and rear marker lights, license plate lights).
Power for the switch portion of the relay comes in off the ignition switch as a green-red to pin 30. Power for the electromagnet arrives from the headlight switch as a blue-white on pin 86. Finally pin 85 (black) is the ground side of the magnet. Dave Barton's web site has a picture of the Bosch version:http://www.davebarton.com/volvorelays.html
The part numbers are Bosch PN 0332-015-006 and Volvo PN 1259926
. Models 86 - 89 mounted the relay on the firewall in the cabin behind the brake pedal; after, until production ceased in 1993, it was mounted with a clip on a metal panel below the centre dash air supply right behind the change tray which is the formed upper edge of centre console.
Do this first: Determine if your relay is mounted on the firewall. Pull out the foot mat, remove the felt cover that encloses the pedals and roll back the carpet to expose the area behind the brake and accelerator pedals. There should be two relays mounted on the firewall. You'll have to pull them both off to determine which is the headlight relay as the factory sometimes switched their position. In good light, you're looking for following numbers inscribed beside each pin: 30,85, 86, 87 and 87A. If you found it, good on ya'! Ensure the connector is in good condition.
If it is, substitute a known good relay. Many independent shops will have old parts boxes of them, and this was a very common relay used in a number of circuits on 240s and 700 series vehicles. You can also find it online, at wrecking yards and some individual wreckers and part shops specialize in Volvo new and used parts. In Canada try Chapman Motors in Cobble Hill, B.C, Northern Import Auto Supply in Huntsville Ontario, The Volvo Guys in Toronto Ontario or Hamilton's Corner Garage in Guelph Ontario. The U.S. has a number of suppliers who will ship you a part. A new relay typically is priced between $25 and $35. If you have to order one, you're best advised to buy new.
Do this second ('cause it's a lot more work!). To get at it you have to pull out the air louvre assembly, disconnect and remove the radio over top, disconnect and remove the instrument cluster, disconnect and remove the headlight switch. Finally, unclip the plastic frame which houses all of this and remove the air ducts to expose the relay. On the metal panel will be 3 or more relays. The headlight relay is the leftmost.
To remove a dash-mounted relay, remove all fasteners for the centre console, move it forward and remove all connections to its controls. Remove the console. With a screwdriver pry up on the holding pins of the clip to which the relay is secured until the relay comes free. (You may need to move some of the wiring harnesses and perhaps disconnect a connector pair or two to provide room. Push the relay and the socket to which it is attached down until it appears in the opening left by the console's removal. You may see heat damage at pin 30 of the relay. If you do, replace the connector (a pain), or grind off the nylon housing for pin 30 and replace the spade lug connector (easier). Re-connect the remaining 4 lugs of the connector to the relay and the new connector to pin 30.
Connect the headlight switch to its connector, and turn the ignition switch to position 3. If the headlights and running lights come on, you're done. If not, replace the relay. Reassembly is the reverse of disassembly. Newbies should mark each disconnected wire with masking tape on which is written the location to which it attaches.
Judging by the number of frustrated people complaining about this condition, the need for this explanation is plain. I hope it proves helpful. If you're still having trouble with your lights, email me at firstname.lastname@example.org