Newbie, Boot Light Question

[Twoflags]

Hi all,

New to the forum and indeed the XC60.
Recently bought a 65 plate 2.4 D4 auto SE LUX NAV with 50k and FSH. Really well specced (BLIS, Anti collision, rear sensors, lane assist, Harmon Kardon sound, factory 20” alloys, upgraded leather, keyless stop start, HDD jukebox, electric boot etc etc) for what I think was a steal at £15k

Loving it so far, but (there always one). The boot lighting is, for the size of it, doggers. I’ve purchased two 500mm 5.6w LED under cupboard light that fit nicely on the old cover. Wires it in to the internal boot light and had it working for 20 mins or so. Sadly, it has now packed in and the factor boot lights stop working. If I disconnect them and power cycle the car the call factory lights reset.

Looking on some MY10 wiring diagrams it appears the lighting may well run through a CEM moduke which looks to be CAN linked. I’m guessing the unit is not liking the extra load and shutting down. Can anyone confirm?

The internal boot light had three wires to the plug, a white, a blue and white and a brown.

The lamps are currently tapped in to the white/ one and white terminals, is this correct?

[rxtian]

Yeah you’re probably tripping the overtemp/over current on the solid state relay driving the boot lights.

Your best bet is probably to use the boot light to drive a relay, which switches a higher power feed to the new lights. In the V60 there’s a trailer feed in the boot loom under the floor, it’s probably similar in the XC60

[b1mcp]

Are you sure it's not just a timer kicking in?

I have done the same mod as you and they work fine - although I have 2 x 2.5W LEDs. Not sure I've ever tested it longer than 20 minutes - that's a long time to have the boot open.

The boot lights are not powered directly by the CEM. The CEM switches a relay (internal?) which feeds power to a 7.5a fuse (Fuse 3, Control Unit Fusebox under glovebox) that powers the boot lights, ground lights (if you have them) and the footwell lights. So I don't think stressing the boot light circuit would not impact on the CEM.

The CEM does switch the lights directly (ground switch).

[Twoflags]

Originally Posted by rxtian

Yeah you’re probably tripping the overtemp/over current on the solid state relay driving the boot lights.

Your best bet is probably to use the boot light to drive a relay, which switches a higher power feed to the new lights. In the V60 there’s a trailer feed in the boot loom under the floor, it’s probably similar in the XC60

that was my plan, hopefully the current draw of the relay shouldn't overdrive the CEM, my calcs reckon a draw of around 200mA on a 12v coil. Beauty if there's a fuse box in the boot I should be able to tap in to for the lighting supply.

[Twoflags]

Originally Posted by b1mcp

Are you sure it's not just a timer kicking in?

I have done the same mod as you and they work fine - although I have 2 x 2.5W LEDs. Not sure I've ever tested it longer than 20 minutes - that's a long time to have the boot open.

The boot lights are not powered directly by the CEM. The CEM switches a relay (internal?) which feeds power to a 7.5a fuse (Fuse 3, Control Unit Fusebox under glovebox) that powers the boot lights, ground lights (if you have them) and the footwell lights. So I don't think stressing the boot light circuit would not impact on the CEM.

The CEM does switch the lights directly (ground switch).

Yeah I've tested it directly. With the boot open and the additional lights disconnected they boot lights stay on fine, as soon as i connect the new lights (less than a minute of boot being open) it kills the boot lights completely. Then requires new lights disconnecting and a power cycle of the engine to get the boot lights back on.

[rxtian]

I'd think 200mA would be ok... If you want to be super safe, you can make up a little board with a MOSFET and a couple of resistors and it will draw almost zero current from the boot light circuit.

Obviously make sure you fuse down whatever feed you find.

[Tannaton]

Did you ever resolve the issues of the boot lights going off?

I'm planning to upgrade mine - just wondered how you got on?