Weird Yeti boot light problem

[vRS G60]

Right, 1st off the boot light isn't working.

 

Now the fun begins, bear with me.

 

If I disconnect the light module and put a Volt meter across the wired connector I get 12V showing.

 

If I close the boot with the Volt meter connected it then shows 0V as expected.

 

If I connect the light module to a spare 12V alarm battery it lights up.

 

If I connect the light module back to the wired connector bugger all happens.

 

If whilst the light module is connected to the wired connector I put a wire to earth on the car from the -ve side of the light module it lights up.

 

 

I'm not thick by any means and I've done electrical work on cars for years but I can't fathom this one.

 

Also posted in Tech forum.

[Frenchtone]

terminals of the module making contact properly?

[vRS G60]

terminals of the module making contact properly?

This was my thought however if I attach 2 loose wires from the connector I get 12V at the ends. But if I touch the lamp module with the loose wires nothing happens.  :think:

[Llanigraham]

Boot lights normally switch on the negative side. Have you taken that into account?

[Gizmo]

How about trying another light, are the glovebox lights the same?

[vRS G60]

Another check,

No light module connected.  

1. +ve meter terminal connected to +ve wire and -ve meter connector to earth on body 12V shown.

2. +ve meter terminal connected to +ve wire and -ve meter connector to earth wire 12V shown

 

Got in the boot and shut the boot lid. Same connection as 2, above 12V showing so constant 12V input.

Tried the earth of the meter to the earth of the connector (1 above) and not quite nothing, a slight voltage showing.

So Yes switched on the -ve side.

 

Another check. No boot open warning on Maxi Dot. But I guess this is linked to the light being on????

[Frenchtone]

multimeter? tested continuity thro' the module should give some sort of reading, if above 1M the units duff1

[vRS G60]

How about trying another light, are the glovebox lights the same?

Hmm not sure. I want to get this sorted because I have the LED upgrade light on it's way.

Still, it wouldn't work attached to the alarm battery if it was the light module at fault I'm guessing.

Everything's pointing to the boot catch.

[vRS G60]

Tried a continuity check.

Between the 2 connector terminals - nothing.

Over the diode - nothing.

Output side of the diode to -ve terminal continuity.

 

So this suggests the diode? If so why did it work on the alarm battery?? Or is the meter not powerful enough to push current through the diode?

[Frenchtone]

try it both ways - should give  a reading one way

[vRS G60]

try it both ways - should give  a reading one way

Tried that, no. I even shorted over the diode with a wire whilst the module was connected and it still didn't light.

 

It's looking ever obvious to be the sodding boot catch. Still, I have 12 months warranty but it's just he inconvenience.

[Frenchtone]

can you link the negative(earth side) to earth via the meter set to buzz and the activate the door sytem should also get continuity buzz with the door open - that would verify switch working or not!

[lfc958]

Noooo you just picked it up & now you have this issue. I wouldnt even make the effort you have - Straight back to dealer - & request it is sorted.

[vRS G60]

can you link the negative(earth side) to earth via the meter set to buzz and the activate the door sytem should also get continuity buzz with the door open - that would verify switch working or not!

I've done a similar thing. Just connected the -ve side to earth via a loose wire whilst the module is connected and the light comes on.

[vRS G60]

Noooo you just picked it up & now you have this issue. I wouldnt even make the effort you have - Straight back to dealer - & request it is sorted.

And it's raining   

[Frenchtone]

yehh but doing that does not test the switch if its on the earth side - you need to connect the earthside of the unit to earth using the continuity circuitry then open and shut the boot if it buzzes whilst open the switch works if it don't with the door shut that's, and proves switch is correct also

[vRS G60]

Continuity connected between earth side of switch & body -

Boot open buzzer.

Boot shut no buzzer.

The fault is on the earth side, the earth wire goes to the boot catch. Fairly conclusive I think.

[Frenchtone]

proves the switch works and also the earth side wiring is good - contacts within the light module holder probably otherwise trip to dealer!

[vRS G60]

Not really. I connected the continuity test to the body not the earth wire. Any connection to the earth wire and it doesn't work. If it was the holder it wouldn't work when connected to a separate battery.

 

 

proves the switch works and also the earth side wiring is good - contacts within the light module holder probably otherwise trip to dealer!

[Llanigraham]

 

 

Another check. No boot open warning on Maxi Dot. But I guess this is linked to the light being on????

 

Boot light is not included in the bulb failure system.

[vRS G60]

Boot light is not included in the bulb failure system.

No, but doesn't maxi dot show that the boot is open as it would a door?

[Llanigraham]

Sorry, misunderstood you. Yes it should.

 

Sounds like the switch is duff. Where is the switch?

[vRS G60]

Sorry, misunderstood you. Yes it should.

 

Sounds like the switch is duff. Where is the switch?

In the boot catch.

 

From the manual -

 

The door, luggage compartment and bonnet ajar warning lights up if at least one

door, the luggage compartment or bonnet are not closed. The symbol indicates

which door is still open or whether the luggage compartment door or bonnet is not

closed.

The symbol goes out as soon as the doors, luggage compartment door and bonnet

are completely closed.

 

No warning on mine if the boot is open,

[Merlinman]

You need to look carefully - if the tailgate isn't properly closed, the rear window in the Maxidot graphic appears 'filled in'

[vRS G60]

You need to look carefully - if the tailgate isn't properly closed, the rear window in the Maxidot graphic appears 'filled in'

Taken another look, thanks, boot shown as open I was expecting something like the door shown ajar. But light still not on. Tried another test.

Loose wires inserted into wired block then attached to an H7 halogen bulb, nothing. Earth wire taken out of connector block and earthed on bare screw attached to body, bulb lights.