Isolating fuses for INT 2

[SFGrenny]

I am looking for help isolating which additional fuses, if any, (besides FL29) may have been blown overloading INT 2?

I wired up chase lights (2 BD S2 Pros), which are rated to draw 1.7amp each, along the frame rail, up through the passenger footwell, and into INT 2. It blew the fuse. (The light indicator on the overhead switch powering INT 2 stopped working and I got NO reading on my voltmeter from the wires in the footwell). I replaced fuse FL29 w/ 10amp Mini fuse and it appeared to fix the problem i.e the indicator light for the INT 2 switch on the overhead aux panel came back on when the switch was flipped on AND I got the expected reading off the voltmeter from the wires in the passenger footwell.

Unfortunately, when I reattached the leads from the chase lights, it appears to have re-blown. I replaced fuse FL29 again but this time the indicator light on the overhead switch does NOT come back on when I flip the switch and there is NO reading on the voltmeter from the wires in the footwell.

I am trying to shortcut having to pull a bunch of individual fuses to check which additional ones might have been blown? Any recommendations for where to start?

FWIW I have the overhead aux panel. All the other switches are working fine i.e. their indicator lights come on and the accessories that I have wired in to these respective switches all power up fine: i.e 2 BD LP6 into EXT 5, and single Strands Siberia SL into EXT 2, 3, and 4.

TIA

 

[TheDocAUS]

Have you looked at the Rok Dr Guide?

I did have another fuse impacting my left footwell power outlet, but I cannot remember which one it was. May be FL28, but that is a guess. Sorry I cannot be more helpful.

@Rok_Dr

 

[Rok_Dr]

Unfortunately I can't advise anything definitive to check. Some long shot thoughts before pulling everything:

• Check FL28 as noted by @TheDocAUS and also FL30.
• FL04 which fuses the accessories relay that sits upstream of the INT1/2 switches, but if this is blown then there is a serious short somewhere in the light wiring as its a 60amp fuse.
• Look at fuses FC21-23 in the centre cockpit fuse box. They fuse other 12v outlets in the car.

Finally the high amp optional wiring has its own fuse box, so as you have observed these switches are not effected.

Let us know how you go.

Cheers
Steve

 

[Lemon35]

This is an old thread but the only relevant search result;

I am having the same issue as the original poster and cannot identify the issue. INT2 fuse blown. Replaced and confirmed the overhead switch now illuminates when powered. Can't find any other blown fuses. Everything else functioning including the 12v Sockets.

Any recommendations or updates to this original thread? I'm in the process of relearning how to use my multimeter that I haven't touched in years.

Thanks
-Pete

 

[TheDocAUS]

Have you worked your way through the Rok Dr suggestions above?

I know there is another relevant fuse, but I cannot member which one.

If you find the answer, please come back and tell us.

PS keep the mulitmeter away from any airbag fuses.

WARNING FROM HQ94: "when looking for shorts and drains and working or testing around the steering wheel or airbags DO NOT TEST SRS AIRBAGS & SEAT BELT PRETENSIONERS without knowing the circuit and what you are doing. Measuring resistance, OHMs and stray millivolts mV can set off airbags, and seatbelt pretensioners."

 

[Lemon35]

Multimeter reading the affirmative 12.4v at the INT2 termination. Only active when toggled overheard via INT2 switch. Have not found any additional fuses popped and went through the Rok Dr book for what I considered to be relevant (Fantasic work @Rok_Dr by the way).

With that positive flow at 12.4v my understanding is there can be a few things "upstream" causing the issue. I'm not going through and redoing my installed DTP plugs to see if that was just user error compounded with the first fuse pop mistake.

Edit: AI lesson just corrected that assumption. I'll run a some amperage draw tests on the INT2 drop.

 

[Lemon35]

No luck yesterday before I called it quits and reassembled so I wouldn't lose the whole weekend in the garage.

I got to the LHD INT1 and installed a DTP plug but those wires were also providing no power. I left those plugs tucked high against the trim so I can access and troubleshoot without a huge amount of disassembly when I have time.

Fuses FI28, FI29, and FI30 all functioning properly. Overhead switch lights are illuminated when toggled.

No power to the footwell points; in my mind the issue is upstream of FI29 and FI30 at their next juncture.

Maybe interesting to some:
Pulling FI28, FI29, FI30 fuses when observing the overhead switches is as expected - the illumination of the switches fades immediately. This is not the case with the EXT 2 and EXT3 fuses (FL01 and FL02), those switches remained illuminated overhead when toggled, when pulled. Not sure why that function would be different for the optional "high load fuse box" but it could make quick diagnostics of those fuses more difficult if you have a problem with those circuits.

-Pete