Loss of power

[Gus Carfi]

Quandary sudden loss of electrical power
Engine stalls, then kicks over when turn ignition key but no power to gauges and engine start although kicking over will not start. After a few minutes start priocess again turn ignition it kicks over no power to guages then for no reason gauges come Alive and turn over ignition and it starts straight away and happily off we go.

Any ideas what this could

[Fishcop]

So many possibilities

Start with the obvious - check the earth straps (engine/gearbox to chassis, battery boxes, and alternator to engine).

[Classic]

When you say you have no power to your gauges, can you hear the fuel pump running? CDI?

As John has said check your earths. I would add to check the earth behind your clock. If you're losing all power to your gauges, I'd be looking at the fuse panel, the relay from your ignition to your instruments and then the ignition switch itself.

[Merv]

Earths are the usual suspects (I have added some) and then the ignition switch itself.

[Gus Carfi]

Thanks guys I'll check it out the earths on the weekend me keep you posted

[PD Targa]

I was thinking ignition switch, my sunroof would not work on my 72 unless the key had a slight turn back.

[Merv]

I can't recall if the 911 has a starter relay, and I can't see which model of early car you have Gus. John and others would recall. I know that the 356 doesn't and the direct current to the ignition switch kills it over time. They are almost irreplaceable on the 356. Most fit a starter relay to 'insulate' the ignition switch (the first thing I did).

[Fishcop]

I can't recall if the 911 has a starter relay, and I can't see which model of early car you have Gus. John and others would recall. I know that the 356 doesn't and the direct current to the ignition switch kills it over time. They are almost irreplaceable on the 356. Most fit a starter relay to 'insulate' the ignition switch (the first thing I did).

911s don't - But I did add one to mine...

[Merv]

Thanks John. Always a good idea as those old ignition switches take some real punishment.

[epilot]

Thanks John. Always a good idea as those old ignition switches take some real punishment.

and cost a truck load to replace ...

[Merv]

Joe Leoni is the doyen of all things electrical on old 356's cars and his books of simple coloured circuit diagrams and relay additions are great stuff. I have some PDF versions for the 356 that have been invaluable. I think he also has some for the early 911's

[72_sporto]

Hi Gus, I think that I had something similar happened to my 72 about 15 years ago. Just driving along then everything died. (Actually, come to think of it, I was trying to impress a young work colleague on a lunch date and accelerating pretty hard when it died- had to walk back to work!) I'm pretty sure it was a slightly corroded fusebox contact. The combination of high current through a dodgy contact and vibration can do all sorts of strange things. My advice is to look carefully as they can be hard to see.

[PCM911T]

Checked the battery terminals? and earths as above.

[Gus Carfi]

thanks for all the advice guys, i have checked the earth straps around the batteries and have checked the fuses, however everything looks remarkably pristine albeit a little dusty. I've given the area a good clean.

Car is starting and has power without drama, however i wonder if it will happen again.

On Friday i will check connections around the ignition switch then jack her up and check the earth straps around the gearbox engine,

but with my targa things are usually simple and just need a common sense approach, i remember when i couldn't change gears and feared it was a gearbox rebuild but it turned out being a $5.00 rubber bush or the time i had an oil leaking from the rear of engine but found i had greatly over filled with oil, or the time .............ill stop there i think.