Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Quirky Feature or a wiring fault!

I'm a recent 1996 Plus 4 (Rover T16 Engine) owner and I was driving the car the other week for the first time in the dark with the headlights on. All was good until I got home. I pulled up onto the drive and got out to open the garage with my keys in hand and the Engine was still running! It would appear the engine will run with the ignition off while the head lights are on.

Further investigation the following day confirms that the engine will continue to run with the ignition off, key removed, while the headlights are on. If I turn the headlights off, sidelights still on, the engine stops.

So, if there are any T16 owners out there can you confirm if this is a feature or a wiring fault?

And if its a fault does anyone have a wiring diagram?

Hi! Strange! No idea, unlikely, but I will have a go at mine tomorrow and see what happens. There is a M16 wiring diagram on GoMog, same as T16 I think, not clear but may be of help. Good luck, I'll report further..........

The headlight bulb filaments are fused individually using fuse positions 4 -7. Fuses 4 & 5 are fed by a single blue/red wire to feed dipped headlamps from dip/main stalk. Fuses 6 & 7 main beam from single blue/white wire fed similarly. Check no extra wires have been added by way of a PO bodge. Ditto the solid blue wire, one of three from the light toggle switch feeding to dip select stalk.

I replaced the ECU on my T16. It would not idle, idle perfectly or at 4000 rpm.
The replacement by passed the immobiliser. I wonder if your car has replacement ECU and power for the headlights also by passes the immobiliser to power the ignition.

Thanks for all the helpful info. I shall investigate further and update here later.
Further investigation today found it only continues to on dip beam. Switching to full beam kills the engine. The documentation that came with the car shows wiring repairs were done following a mouse infestation.

I don't know if the ECU has been changed but there appears to be no immobiliser, so I believe it has been disabled. I'll look to see how thats been done. I had seen the M16 variant wiring diagram which is very helpful but unfortunately is incomplete.

Have a look at the dim dip unit if it's still there, and if so suggest removing it completely. If it's been re-wired incorrectly that could cause back feeding to engine systems. It's a daft idea IMO and was outlawed shortly after it's introduction.

That suggests that the headlamp circuit is holding on the ignition relay. So I suspect the lights have been wired through it.

Years ago, a friend with a Land Rover Defender broke down in Chippenham. I was there. The RAC man attended and identified that the gear linkage had chafed the loom and disconnected the ignition feed. His fix, which he called a "temporary repair", was to scotchlock the sidelights into the ignition feed, so it worked with sidelights on.