Electrical Problem - Everything "on" when ignition "off"...

[UpTheIron]

Hoping for some suggestions... my Tuscan presented itself with a dead flat battery a few days ago after not being used for a few days. So flat I had to get in the secret way.

Started charging it and clearly all was not well. With ignition off (key out) all electrics are live and working.

I have since identified:
- the problem goes away if the ignition coil fuse is removed
- car will still start and run with ignition coil fuse out
- problem returns with fuse reinserted, car will start and then continue to run with key removed until the fuse is removed.
- with ignition off, voltage at dash and alternator is 10.4v, with it running, 12v+ as expected.

Car electronics are not my area of expertise... what do I look at next?

[Oneball]

Sounds like the ignition barrel itself, they're just a bunch of contacts inside that are operated by turning the key. I guess there could be a short in the wiring to the switch but I'd guess the most likely cause is inside the switch itself. See which of the contacts on the barrel is live and what effect turning the key has.

[Speed 3]

I would check the fuseboard for corrosion evidence as well. My car has a water ingress problem that's effectively been there since build and no-one's been able to cure it. Water tracks down around the steering column and some of it ends up on the fuse board. It occasionally leads to all sorts of weird behaviours like things starting without their control signal or not working when they should.

[UpTheIron]

Fault remains if the ignition fuse is pulled (and ignition switch no longer works at the point). No obvious corrosion / water damage but will have a closer look.

[PetrolHeadPete]

Might be worth pulling each relay and buzzing it out to make sure contacts haven't welded...normally there is a little connection diagram on the top of each one which will help.

[Tuscanuwe]

Check relay for ignition on, if it is not opening anymore after shut off, you can have this problem.
The fuse is in this case opening the circut.

A bit shaking at the cables can also bring results in case of broken or faulty wires or connections.

Uwe

[maxkressbronn]

fSuggest you check the ignition barrel first. Had this before, there is a little pin at the rear of the barrel protuding into the electrical switch, that was broken off no longer transmitting the movement of the key to the switch. Godd luck, Markus

[UpTheIron]

Thanks all. In true TVR fashion I took the airbox off had a poke around the alternator and coil pack. Nothing obviously wrong. Problem remained.

I then put everything back together so I could see drive it to my local dealer. Once reassembled the problem disappeared!

[robsco]

Not sure if this helps but my T350 had a problem last week where the dash stayed live even when ignition key was removed. The only way it would turn off bizarrely was by pressing the brake pedal. I suspect alternator in my case but I’ll refer back when sorted if it helps.