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MG MGF Technical - Sunmate sets alarm off

Last month I got a Mike Satur Sunmate to stop the cat using the hood of my TF as a bed/scratching panel. Whilst it works brilliantly for that, it seems to be intermittently causing the alarm to go off. It happened once at 3am a few weeks ago - I unset the alarm, checked everything looked ok, reset it and it was fine after that so I put it down to a stray minicab radio signal or something.

Yesterday, it went off again at 4am - this time I unset the alarm, checked everything looked ok and set it again. Once it had settled down, I happened to touch the rear left edge of the Sunmate's bead which you trap in the boot gutter - the alarm triggered again immediately. I unset again, opened the boot, rearranged the beading so it was further from the left boot hinge (and cabling) and set again. This time I let it settle, wiggled and slid the Sunmate beading around quite a lot and nothing happened so I went back to bed. Half an hour later, the alarm went off again. Took Sunmate off, set alarm and it was fine for the rest of the night.

I don't think it's a coincidence that it's only gone off with the Sunmate fitted; I've had the car 4 1/2 years now and the only other time the alarm went off was when some scumbag slashed the hood. It's been parked in the same spot every day for nearly a year now and it's never gone off, so I don't think it's a stray signal from a radio or microwave.

I had a look at the wiring in the boot (as well as I could at 4.30am) and although it looks sound it's just in that plastic split tubing so it's not waterproof. It was quite wet yesterday (earlier thunderstorm) so I did wonder if it might have been damp allowed to run into the engine bay by the Sunmate? Any other ideas would be much appreciated!

Cheers,
Tim
T Jenner

Forgot to ask, is there any way of verifying which sensor triggered the alarm following an activation?

Cheers,
Tim
T Jenner

Hi Tim. Is the sunmate an aluminised material? Maybe it is interacting with the microwave volumetric sensor?
Tony

Hi Tony,

It is, yes - but lots of people have them and I only found one thread in the archive about any problems with the alarm (which didn't really come to a conclusion).

Cheers,
Tim
T Jenner

I've had my sunmate for a few years now and while I don't use it every night (car is garaged) I always use it when I'm away anywhere. Famous last words, but I've never had any problems with the alarm going off. I suspect that you have a problem with your alarm, but it's not the cover that's causing it. I think I would have a look at the wiring loom again at the rear hinge.
David Clelland

As usual, the BBS gets it right (hopefully!)! Had a closer look, one black wire broken and another black wire with stripped insulation. No idea what they do (both black) but no doubt they wouldn't be helping matters by being broken. Not much slack in the cables, so soldered the broken wire together and wrapped both damaged wires in insulation tape, then taped up the split tube again and have cable tied either side of the join to the rigid part of the hinge. Hopefully that will prevent too much flex or strain at the damaged section and move the flex to another part of the loom. I did notice the way it was originally routed caused a sharp kink in the loom where it broke, the way I've routed it now is less sharp. Fingers crossed for a proper night's sleep now!

Thanks again,
Tim
T Jenner

Hi all, where abouts in the boot is the alarm?? my one has just started to go off alot now to the point I have to remove the horn fuse everynight. Funnily enough it started after I shut the boot a bit too hard the other night!
P Atkins

The alarm isn't in the boot. However, the wiring loom which is attached to the nearside boot hinge is usually the culprit. Due to the opening and closing od the boot lid, over the years the wires tend to break and cause funny electrical problems - the alarm going off is just one of them. Strip the tape back and have a good look at all of the wires to see if any are damaged. They tend to break down near the main loom - all the more difficult to get at. If you do find one that's broken it's often easier to fit a new piece of wire in rather than trying to join the two broken ends. I also left the bottom hinge clip off mine so that the wires aren't so tight and get a bit more room to move.
David Clelland

These are the boot lock alarm micro-switch wires.
1.5/2mm crimp sleeves and heatshrink sleeving is the repair kit, or £50 to £70 to your favourite 'mg specialist'
Geoff F.
Geoff Farthing

I have the same problem using a car cover.....and thats aluminiumised !
Paul Carugati MGF

Just picking upon this thread, I have resently removed the door cards, speaker and water shedder whilst replacing the window regulators. During the time the car spent without door cards or shedder, the alarm would go off at sunrise (sudden change in temperature) about 30 minutes after arriving at work (temp drop?) odd times in the day or night when the wind came from the north, odd I know.

Anyway. door cards back on...no problem. dont know how the alarm is set-up but I had to use the key whist the door cards were off.

Are the noted problems on cars that have had the shedders removed, torn ??
MG Mike

This thread was discussed between 04/07/2008 and 05/08/2008

MG MGF Technical index

This thread is from the archive. The Live MG MGF Technical BBS is active now.