My headlights go out when I try to switch to highbeams. I've checked the socket and connectors on the square silver relay in the cabin by the brake pedal and they all appear ok. When I operate the highbeam stalk, I can hear the relay under the hood, on the left fender, click. How do I determine which relay to replace, or is there another mechanism that I should check? Thanks.
Marlin

Been there, done that with my daughter's S70. It took me almost a week of tracking schematics, etc to find out it was only the low beams bulbs were BOTH DOA.
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'86 sedan with 450,000 miles on the original engine and automatic transmission

Don't mean to be insulting, but are you sure the the bulbs are good? I've been know to spend hours trying to track down a problem that was right in front of my eyes. Before I did anything, I would use a testor/test light to see if power is getting to the plug when the stalk is clicked.

Hope it is nothing major.

Mark

I'm really embarrassed to admit it, but both bulbs were out. I've don't think I've ever had both of them go at the same time before. Thanks.
Marlin

That would have gotten me. I've changed dozens of 9004s in Volvos and other cars and never NEVER seen one with anything but a pristine high beam filament. To have two out in once car says you need to go buy a lottery ticket.
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Art Benstein near Baltimore

To err is human, to moo bovine.

Excellent! I'm glad I could be of some help and the the fix was simple and cheap. Or I guess I could say that I'm glad you've seen the light.

Don't be embarased. All of us have done it, we just don't normally tell anyone. It's much worse when you spend a lot of time and sometimes money to "fix" something simple.

Mark

Make sure the relay under the hood is fully clicked into the holder. I had the same problem this past summer. I could hear the relay clicking too. I grabbed the relay and snapped the connector all the way on and haven't had the problem since. Good luck.

Fortunately high beams don't go thru the bulb failure relay, just the step relay under the hood and the main headlight relay by your feet.

Do they work when you try to flash the highbeams rather than switch them so they stay on? Does the high-beam light in the instrument cluster light up?

If the cluster light comes on and there are no high beams under either On or Flash, then I'd look for a wiring fault between the step relay and the headlights. The warning light would indicate the step relay is working correctly.

John

The cluster light comes on, but the highbeams do not come on either in the flash, or when stalk is released from flash and cluster light is on.
Marlin

Okay, then I would start with cleaning and re-seating the red high-beam wires where they connect to the step relay. If no joy then, clean and re-seat the connectors where they clip onto the back of the bulbs. If still nothing, I'd check the red wires for continuity b/w relay contact and bulb contact, and confirm something hasn't cut them somewhere. And at that point, I'd start to wonder if there isn't a bad solder joint inside the relay where the prongs for the headlights meet the prong for the warning light.

John

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1989 245 233K / 1993 945 127K