Good Morning Spook,

The following is a quote from Dave:

"Starting in 1989, Canadian requirements for DRL became different than in the USA. The minimum requirement was for at least reduced intensity headlights that cannot be turned off when the engine is running. There is no requirement that forces taillights, marker lights or dash lights to be on, although they may be. For safety reasons, Volvo wisely chose to implement DRL with full intensity and all other lighting on, exactly the same as night driving. Some other manufacturers went with the minimum of reduced intensity headlights only, presumably to add maybe .01% gas mileage to help meet fleet fuel efficiency requirements and extend the life of lighting and charging components during the warranty period.

In our Volvos, this was all accomplished by the headlight switch and modifying the contact arrangement. The wiring harness connector and the headlight relay remain the same. Apart from part number, the way to tell them apart from the pre-1990 switches is a missing spade contact on the back of the switch

In the late 1980s, Volvo started using a more universal headlight switch in the USA market 740s/760s that could be made to function like a Canadian-style DRL switch using a small recessed screw. That may have been okay in other markets, but it did not meet the letter of the law in Canada, so Volvo had to design a non-modifiable switch.

Although I very much believe in the safety benefits of full time DRL with all lights on, I still want to have the option of turning the lights off when needed, whether it's running the engine while working on the car or sitting in parking lots on a cold winters night needing the heat on. First thing I did when I got my 940s was to swap in a used pre-1990 740 headlight switch -looks exactly the same and gives me the benefits of both worlds.

There's a section on DRL in the 700/900 FAQ with a few more details."

It looks like I could use the American version of the relay and either run it all the time with lights on or just run it with lights off. My 240 GLT does not have daylight running lights.