The Rover-Landers of BC

When I got my '99 D2, the daytime running lights worked as did the remote "pathway lighting" function (which the RAVE manual indicates is operated by the DRL circuitry). Something has happened in the last while and they've quite working. To be honest, I haven't spent much time troubleshooting, but I've checked the fuses shown in RAVE to be related to daytime running lights and all appear fine, therefore I'm assuming that the problem lies in either the DRL resistor (which took me a while to find, but one of the TSBs identified it behind the left hand headlamp. The part I haven't been able to locate is the relay driving the DRL function. Is this one of the relays plugged into the interior fuse box? Is it mounted to the back of the interior fuse box? Is it elsewhere? I haven't started a detail trace of wires yet -- I'm still referring to the schematic and was hoping to avoid a bunch of detective work if someone just has the answer.

Secondly, I'm building my onboard air system. There's no room for a york or other belt driven compressor, so I'm going the VIAIR route. I have two 480 pumps that I have built a bracket to mount outboard of the right hand rear control arm bracket (effectively, just below the passenger seat). I want to wire this system so the compressors (which are going to draw roughly 40 amps when running) will only operate when the engine is running. I see three options for this....
1) a voltage sensing relay to energize the compressor circuit when voltage exceeds 13v
2) a relay tied into the oil pressure sending unit (which is a ground point)
3) a relay tied into any other power source that is hot ONLY while the engine is running (not just key-on). Does anyone have any thoughts about an easily accessible power source for this?

The relay will control a fused power feed from the battery to the compressor bank, which will then be further controlled by a pressure switch in the (to be installed) air tank (which I am mounting below the fuel filler neck).

Any thoughts/comments are most welcome!

I traced wires and circuits today and am 99% certain that my DRL resistor packed it in. I'm now in search of a replacement....and if I'm really feeling ambitious, I'll dig through the boxes of electronics parts and will likely find high power resistors that I can make into a replacement .75ohm pack. Of course that is based on an assumption that DRLs are landing high on my list of priorities (which they are not!)

I've decided to run a voltage sensing relay to supply power to my compressors. While I'm waiting for the post office to deliver components I required, I finished making up my OBA compressor bracket. The bracket mounts outboard of the right hand frame rail, just outside of my ACE valve block. It bolts into two pre-existing holes in the rear control arm bracket (just above the bushing) as well as to the passenger seat right-rear mounting bolt. Air intake will be from behind the right taillight, similar to the driver's side SLS air intake.
Over the next week, I need to figure out mounting options for an air tank. I intend to mount the tank (or maybe two small tanks to best use the space) under the fuel filler neck.