Hello, I'm new to the Forum but have spent some time surfing around to see if I could find an answer to my problem. Lots of similar (hence the title!) but nothing quite the same.

The problem of fuse F35 (direction power module) blowing has been going on for a couple of months; unfortunately there doesn't appear to be much repeatability so it's really hard to pin the problem down. The basic result, until recently, has been that I lose my indicators, hazards and high/main beam. Replacing the fuse would fix all that for a while before it blows again. My new 'symptoms', both have which have happened a couple of times are (1) that the "direction indicator" arrows in the instrument panel are on continuously - even when the ignition is off and the key removed and (2) pressing the headlamp on switch on the key-fob sets off the alarm but does not turn on the lights.
A garage has been trying to help me and so far they have (1) disconnected the alarm pre sounder (have I got that right ?) which apparently sits in the front right wing (2) replaced the GEM module with a used warrantied part (3) changed all the indicator bulbs (4) disconnected the tow hitch electrical connector socket. None of these have fixed the issue .... sometimes it's fine for a couple of weeks, other times the fuse will blow the next time I use the indicators. The last couple of times has been when locking the car with the key-fob - the car locks ok and the indicators flash briefly at which point I think the fuse blows.
Although at the moment the alarm doesn't sound with the key-fob light switch, the "direction indicator" arrows in the instrument panel are currently on (with no ignition). Presumably they are getting a direct feed from somewhere and tracking this down might help solve my problem....? Fuse F35 is blown (I haven't replaced it yet) and I have removed the following fuses one at a time:
Engine compartment: F2 (front fog lights, master light switch) and F29 (left hand dip, master light switch, head light levelling, instrument cluster)
Passenger compartment: F2 (instrument panel etc), F4 (accessory connections) and F19 (tow bar module)
None of these removed the power source from the "direction indictors" which are still on .... or to the instrument panel. I would have thought F29 (engine compartment) would do that - if not, which one?!

Intermittent electrical faults are a nightmare to resolve and any help tracking down the cause of F35 blowing would be much appreciated. Thank you

 

Can't edit my post .... but I have just realised that the headlights don't come on with the key-fob at the moment because F35 is currently blown!

 

Hi Mermaid,

That is a tough scenario....intermittent faults are just the worst PITA to find.
F35 appears a general fuse that goes to the GEM supply.
Most of the high current drawing devices and functions of the car have specific fuses protecting the device and supply source.

Notable as directly driven as unfused outputs from the GEM are:-

• The array of interior lights (glovebox, cigarette lighter, map, interior cabin, foot wells etc).
• All of the turn signal lights ( markers and front and rear turns in the clusters)
• Security sounders (passive and horn)

Isolate interior light circuit.
I might be helpful for diagnostics to intercept the GEM output wire to the interior lights (Black/Pink stripe from plug CA86 pin 3) and add an inline protection fuse (7.5 or 10amp should do), just in case you have an intermittent bad lamp holder, bulb or pinched wire in that circuit. Better that inline fuse blows than F35. The interior lights will come on when you unlock the car, so they could be a failure point to consider.

Turn lights and repeaters
The GEM seems to directly drive the indicator lamps with no secondary fusing. So again you might want to add fuses to help isolate the various outputs from the GEM to these.
Front lights from GEM plug JB172 pin 3 (orange wire) and JB 172 pin 4 Orange/Yellow stripe) (5amp fuse should be OK)
Rear lights from GEM CA 86 pin 2 (Orange/Yellow stripe) and CA 87 ping 4 (Brown/Red stripe) (5 amp fuse should be fine)

Security sounders
Only the passive sounder is directly driven by the GEM via CA87 pin 1 (Orange wire)
The horn sounding is also driven from GEM via IP5 pin 14 (Black wire) to the horn relay coil (relay R2), so this should be a low current output to just the relay coil.
If you are still hunting at a later stage, you might wan tot isolate these as well but both will be low current.

Now all of this troubleshooting is to try and find the cause of F35 blowing, isolating all avenues so the next event may trigger a added sub fuse to lead you to the actual fault.

What is not explained is the instrument cluster giving you the ever present indicator lights.
The cluster displays are data driven from the GEM etc.
So if the GEM has been replaced (which is likely the source of the indicator light command to the instrument cluster, I am wondering if the instrument cluster is just highly confused and if a possible power reset might clear that issue, or if it has a permanent fault whcih might require the cluster to be opened, checked for possible faulty cable connections or outright replaced.

Might pay to see if you can focus on F35 blowing first to see if that turns out to be a peripheral loom chaffed, shorting etc, then go after the cluster anomaly.

 

Mermaid, I am venturing to guess thta you have an instrument cluster that is got some broken solder joints on it and it is causing what you are seeing. This may sound like an odd check, but I would say to put in a new fuse F35 and start the car. Make sure everything is working like it should. With the car running, get into the driver's seat, make a fist and pound on the dash above the instrument cluster as you have the turn signals and/or headlights on. If you hit the dash and things go crazy on you, then this would be a good clue as to your problem being located near the instrument cluster.

 

Thank you for your help ...... this is just to update the thread and 'close' it - hopefully!
It's taken a while to start believing the problem has been sorted (darn intermittent electrical faults!) and I'm whispering this .... but ..... changing the indicator stalk appears to have fixed things.
Fingers crossed - and I still use my indicators with apprehension!