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sln8458 · 29th June 2020, 16:41

OK, so I fitted a pair of Mercedes DRL's to my 75 a couple of years back.

These https://www.aliexpress.com/item/4000...60424c4dBpmK5E

A while back the near side DRL stopped 'dimming' when I turned the headlights on. The dimming is controlled by a DRL2.

The output from the DRL2 is a single pair, connected in parallel to each DRL.

A couple of weeks back, when I was furloughed, I decided to see what was going on, so pulled the front bumper off and checked the voltage to each DRL. They were identical with the ignition on (full brigtness), then with the headlights on (dimmed). I presumed from this that the near side DRL was faulty and ordered a replacement.

Replacement arrived today so I went to fit it, but first I checked that it worked, been there got that T shirt

. It worked

Not being one to jump in, I thought I would 'fudge' the wiring to the new DRL before swapping the connectors over. Filled with expectation I got my eldest son to turn the ignition on while I watched. Both Lights came on full brightness, then with the headlights on.....the nearside went out. WTF

Made up a short harness to power the nearside from the offside, light dimmed?
Made up a second harness so I could power both from the opposite light, near side did not dim again.

Which ever way I power both DRL's the near side goes out instead of dimming.

My brain now hurts, can anyone offer suggestions?

29th June 2020, 16:41	#1
sln8458 Gets stuck in Rover 75 Contemporary SE 2.0 Diesel Auto 2005 Facelift Join Date: Dec 2010 Location: Norwich Posts: 589 Thanks: 90 Thanked 67 Times in 47 Posts	One for the Electricians OK, so I fitted a pair of Mercedes DRL's to my 75 a couple of years back. These https://www.aliexpress.com/item/4000...60424c4dBpmK5E A while back the near side DRL stopped 'dimming' when I turned the headlights on. The dimming is controlled by a DRL2. The output from the DRL2 is a single pair, connected in parallel to each DRL. A couple of weeks back, when I was furloughed, I decided to see what was going on, so pulled the front bumper off and checked the voltage to each DRL. They were identical with the ignition on (full brigtness), then with the headlights on (dimmed). I presumed from this that the near side DRL was faulty and ordered a replacement. Replacement arrived today so I went to fit it, but first I checked that it worked, been there got that T shirt. It worked Not being one to jump in, I thought I would 'fudge' the wiring to the new DRL before swapping the connectors over. Filled with expectation I got my eldest son to turn the ignition on while I watched. Both Lights came on full brightness, then with the headlights on.....the nearside went out. WTF Made up a short harness to power the nearside from the offside, light dimmed? Made up a second harness so I could power both from the opposite light, near side did not dim again. Which ever way I power both DRL's the near side goes out instead of dimming. My brain now hurts, can anyone offer suggestions? __________________ Mods Fitted: Cruise Control; FBH with GSM (was FrenchMike's Remote) & dash button; Rear Blind; In-line Thermostat; wired in front & rear cameras; Mercedes DRL +DRL2; twin horns, twin usb power outlets, digital coolant temperature readout, Real Walnut dash, Walnut & black leather steering wheel, Walnut Handbrake grip, Towbar with full Rover harness. Rear seat cup holders. Wanted: Walnut auto gear stick handle Mods to do: all done , need to come up with some more.