Hi all,
My newest volvo, an 89 240 after 4 740/940s has a taillight issue I cannot figure out. The brake lights and turn signals work but no running taillights or back up lights. The fuses all look good. I can't find any help in the archives or FAQ's. Where should I start to look? The bulbs look fine, but I haven't tested them.
Thanks,
Palmer

Hello Palmer,
When I got my 92 244 last year, the backup and brake lights were a mess. I am not sure but I think the 89 is like the 92. I had a bad neutral safety switch, a burned out ckt board, some bad socket grounds not to mention a white aftermarket brake light socket that should have been black. You can do any of the following in any order.

Remove the four screws that fasten lenses on each side and inspect the flex circuit board for burned out circuits and the ground integrity. These are about 20 bucks each if bad.

The reverse lights are not part of the bulb out relay circuit so you can rule that item out. There is a single red/black wire that feeds the reverse lights from the neutral safety switch (automatic). Check for 12V when in reverse. I tracked my issue to the neutral safety switch.

For the tail lights, if the front running lights and your license plates are working that means the "main" relay is working. I’d have to then focus on the bulb out relay. Check for voltage at the brown/white wire for the right side and the red on the left. These both go to the press on connector on the left side.

To test the sockets, I connected two wires to the plus and minus battery terminals and tested each socket with the light in the socket. I found a couple with weak grounds and one with no ground contact. It is probably easier to do this an ohm meter but I was sorting out lamp types by brightness at the same time. If there a poor contact you can bend it back in place.

Tom

Thanks, Tom.
The circuit boards look new but i'll check them out. I'll try all of your suggestings and post back.
Palmer

I agree with Tom except for 2 points, where his '92 wiring may differ from your '89:

1) "Check for voltage at the brown/white wire for the right side and the red on the left."
• On the '89 it's plain brown for the right rear.

2) "These both go to the press on connector on the left side."
• The '89 diagram shows the 2 wires go their separate ways at the back. Tom may have been thinking of the backup lights, where the power comes into the left side white plug, to the circuit laminate, then back out an adjacent plug terminal and over to the right side plug.

--
Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Wagon or sedan? They have different rear light assemblies.

For wagon or sedan, the first thing to check is the white bulb holder. All except one bulb holder are black. The single white one goes on the right side and belongs in the position for brake + tail light. It gets a bulb with two nibs on the base. Has two contact prongs for base of bulb and a third for the cylinder side.

There's a matching holder (black) for the left side. Has a total of three connectors, takes bulb with two nibs on base. All other bulbs and holders have a total of two contacts, with just one nib at the base.

If the above doesn't resolve it...

Get yourself an electrical multitester. It will read volts and ohms. Many also will read milliamps or amps, and also continuity (will beep or light if current path is OK). $10 for a low-end analog one, $30-50 or more if you like for a digital one. At Lowe's, Home Depot, etc. You'll need it to verify voltage is arriving at various points along the circuits. You'll also use it to test bulbs. Burned out bulb has infinitely high resistance and no continuity.

I'm not telling you to become an electrical engineer - I'm saying that it's worth your time and money to get this one tool and learn a bit about using it. Over the long run, this will save you many hours stumbling around guessing, and swapping bulbs etc. back and forth to see what works and what doesn't. Get the meter.

Write back, let us know what you found as far as bulb holders and anything else. If you need more then we can tell you some points to test with your meter.

And again - sedan or wagon?
--
Sven: '89 245 NA, 951 ECU, expanded air dam, forward belly pan reaches oem belly pan, airbox heater upgraded, E-fan, 205/65-15 at 50 psi, IPD sways, no a/c-p/s belt, E-Codes, amber front corner reflectors, aero front face, quad horns, tach, small clock.

It's a sedan. I have a digital MM and have no power to the bulbs on the running lights. The brake and turn are fine. I was un sure on how to check the white bilb holder, but the bulb checked out OK. Any more ideas?
Thanks!
Palmer

You should check the wire connector in the trunk under the driver side light cover. It is a small harness with 4 or 5 wires that fits over a tab in the printed circuit. It becomes corroded sometimes and can cause at least the reverse lights to not work (black wires). Not sure if it affects the tail lights.