keeps blowing on my bro-in-law's Magna. Was driving to our place and suddenly smoke started pouring out the vents then engine stopped.

Now no ignition/starter... Have confirmed all fuses+fusible links under dash and in engine compartment etc are OK except fusible link 19 (30A) which keeps blowing as soon as key turned to ignition-on. Clearly the 12V ign circuit has an earth touching somewhere (presumably from under dash smoke buring through wire insulation?)

We have lights, central locking etc but no ignition or start functions. Also an interesting side problem (probably related). The radio is apparently usually only powered via accessory circuit but now works with key out of ignition?!?

According to this diagram (http://www.aussiemagna.com/forums/attachment.php?attachmentid=20854&d=1144287074) the ign switch *appears* to be the culprit...

Any ideas anyone?

PS: He has just had the auto trans rebuilt by reputable workshop last month after complete failure. He also yesterday recalls seeing the 'D' & 'N' dash lights intermittently again which *apparently* is an early indicator of gearbox failure (again?)

k most head units run off a 12v constant and ya varible. get a multimeter to the HU connectors and find out which ones the constant colour and check find out if thats right as it seems they might be crossed somewhere which isn't good lol

Scary. :shock:

Sounds like

1. Radio was wired by a madman on crack. Rip it out.
2. Transmission replacement has resulted in pinched wire / something reconnected wrongly. Possibly A/C compressor wiring as this seems to be related to that ign. circuit.

If you get it started again, get a fire extinguisher if anyone intends driving it.

there are 3 or 4 looms going into an ECU mounted on the transmission tunnel deep under the dash near the firewall.Two of the looms had wires fused together. Separating them doen't work. What does this ECU control and could that be damaged internally?

The cause appears to be lots of greasy water/fluid in and around the looms going into the ECU so obviously water has bridged an earth and an ign wire somewhere. The fan box above is dry through.

Any idea on the source of the water? Anyone heard of this sort of fault before?

Two of the looms had wires fused together. Separating them doen't work. What does this ECU control and could that be damaged internally?

If by fused you meant burnt/melted, I'd be taking the car back to the auto trans shop and making them get it all fixed. The ECU controls the auto transmission, and if it stuffs up your tranmission will go into limp mode and shift quality will be terrible, and you'll probably be stuck in 2nd. If you manage to get the car started without blowing the fuse and these looms have melted together you'll probably find the auto ECU is dead too.

Edit: source of the water.. could be clogged drain hole for the air con so its overflowing somewhere and onto the looms.

Take it straight back to the auto place mate and tell them they've stuffed up majorly.

I agree - they ****ed it. Water is a very poor conductor of electricity (despite what people think) at 12V you will get very, very little current flow (and nowhere near what it would take to blow a fuse). I could explain why, but I have better things to do with my time :)

Cheers
Heath Young