IG2 fuse?

[AuntyWelder]

Evening Folks,
I have an '05 Toyota Corolla 1.4 VVT that has developed an electrical issue, and I was wondering if someone could offer some advice?
The engine was ticking over and then just cut-out and the dash went black.
The engine will turn over, but it won't fire.
I traced it back to this fuse, but whenever I replace it it blows the second I turn on the ignition.
I ran a multimeter to one side of the fuse and I'm getting 12v, but on the other side when I run a continuity test, it suggests a dead short.
I believe the fuse be the IG2, but I can't find it on any of the wiring diagrams in the Haynes manual or anywhere on the internet, so I don't know which circuit it protects.
Any ideas?
Many thanks.

[oldcodger]

Hi,

Cannot find a reference to an IG2 fuse, but if you look on the inside for the plastic cover to that fuse box it should have the fuses detailed inside, a label or moulded into the actual plastic.

The only reference to IG2 we can see is the terminal on the Ingltion switch, and it seems that is the start of the circuity for the fuel pump, ign coils and injectors , so maybe one of them is shorting out,  though first  better to identfy that fuse for sure.

[AuntyWelder]

1 hour ago, oldcodger said:

Hi,

Cannot find a reference to an IG2 fuse, but if you look on the inside for the plastic cover to that fuse box it should have the fuses detailed inside, a label or moulded into the actual plastic.

The only reference to IG2 we can see is the terminal on the Ingltion switch, and it seems that is the start of the circuity for the fuel pump, ign coils and injectors , so maybe one of them is shorting out,  though first  better to identfy that fuse for sure.

Many thanks, Oldcodger,

The fuse cover on my car is odd as it doesn't reference what the fuses protect, just the fuse ratings.

I only got the IG2 fuse idea from a couple of covers I found on eBay from the same model and year car as mine.

However, you've given me a few places to start, so many thanks again!

[oldcodger]

Just found reference to a IG2 15A fuse in the  Toyota  UK Owners Manual, It does seem to match your fuse box layout as fuse number 20.

It states :-  Gauges and Meters, SRS Airbags, Fuel Injection System, Starter System, Changing system, Fuel Heater(if fitted?)

At least a dead short should be easier to find than an intermittant one ....

[AuntyWelder]

10 hours ago, oldcodger said:

Just found reference to a IG2 15A fuse in the  Toyota  UK Owners Manual, It does seem to match your fuse box layout as fuse number 20.

It states :-  Gauges and Meters, SRS Airbags, Fuel Injection System, Starter System, Changing system, Fuel Heater(if fitted?)

At least a dead short should be easier to find than an intermittant one ....

Thanks again, Oldcodger.

I had a rummage around today and found the loom had been hacked about and an extra bank of cigarette-type charger sockets had added and tucked away under the dash with a direct live from the Battery.

Unfortunately, even after I had removed them, it fault still persists.  

It looks like I'm going to have to invest in some diagnostic equipment like the Power Probe ECT2000 or something similar.

[oldcodger]

Think I would use a multimeter and some basic testing before buying something like that Power Probe, which does make me wonder if it would trigger any airbags ??

You say that with the fuse removed,  you place your meter, in continuity mode, with one lead on the non 12v side of the fuse holder and the other to the chassis metal work, 0v,  you register a dead short, yes ?

If so , then try disconnecting the injector and coil cables one at a time and see if the short has gone on the meter.

You could try the removing the sub fuses for the other devices like fuel pump, if fitted, though not sure about the Gauges and Airbags

Would not have thought it could be a short on the Starter or Charging circuits as they have their own high amp fuses

You can download the Toyota Corolla User Manual which details all the fuses  -

https://www.toyota.com/owners/resources/warranty-owners-manuals/corolla/2005

 

[AuntyWelder]

On 3/1/2021 at 3:10 PM, oldcodger said:

Think I would use a multimeter and some basic testing before buying something like that Power Probe, which does make me wonder if it would trigger any airbags ??

You say that with the fuse removed,  you place your meter, in continuity mode, with one lead on the non 12v side of the fuse holder and the other to the chassis metal work, 0v,  you register a dead short, yes ?

If so , then try disconnecting the injector and coil cables one at a time and see if the short has gone on the meter.

You could try the removing the sub fuses for the other devices like fuel pump, if fitted, though not sure about the Gauges and Airbags

Would not have thought it could be a short on the Starter or Charging circuits as they have their own high amp fuses

You can download the Toyota Corolla User Manual which details all the fuses  -

https://www.toyota.com/owners/resources/warranty-owners-manuals/corolla/2005

 

Hi Oldcodger,

Just a heads-up, the issue turn out to be a faulty coil stick.

Thanks for your advice, it was very much appreciated!

Cheers.