Melted wires, car very dead.
 

Two weeks ago at the track, I had a really nice session. I got back to my paddock spot, left the car running and popped the hood to let it cool off.

Then the engine stopped on its own. I turned around and saw a bunch of smoke.

Eventually I figured out that a number of electrical connectors had fallen on my cat. This is the harness next to the transmission that includes the reverse and neutral switches, along with the rear o2 sensor.

The car is deader than dead. No radio, and the windows won't even roll up. So of course it also doesn't start. As far as I can tell, the only wires that touched (and probably also grounded to the exhaust) were the neutral and reverse switches. I think the o2 sensor wiring is fine.

I checked a lot of fuses at the track and couldn't find a bad one.

I'll fix the bad wires, and I'll go through the fuses again, but any advice would also be greatly appreciated.

Thanks!

Well, I think I found the problem. I thought that maybe one of the transmission switches had shorted to the O2 sensor, blowing the ECU. But that didn't seem to be the case, so I checked fuses again. I found the 15A IGN SWITCH fuse had blown. Hopefully once I replace that and fix the wiring, the car is good to go.

not the first time,

I seen melted engine harness all the time :)

u gotta replace it ...

Some time in between swapping my S1 gearbox for an S2 and R/R'ing the engine for a rebuild, the neutral and reverse connectors did their own re-enactment of Icarus. Luckily for me, they weren't so melted as to cause a problem but I made sure that I tied them up out of the way.

In my case, I have also replaced my S1 transmission with an S2. The car has spent about a dozen days on track since then, but eventually those wires fell on the cat. I have an aftermarket one with no heat shields.

It appears that one or both of the transmission switches shorted to ground or each other. Exactly which, I'm not sure. I haven't examined the wiring diagrams closely enough. I cut out the exposed sections of wire, replaced the fuse, and the car started right up. I'll have to work on securing those wires better tonight. For now, at least it works again.

I'm a little pissed at myself for not having checked fuses more thoroughly at the track. This is a thing I could have fixed onsite with a fuse, some electrical tape and a multitool.