Driving into work today I noticed that my tacho had stopped working.

About a minute later things started going like I was running out of fuel.

No fuel pump sound with acc. on.

Initially nothing when I turned the key but then the engine turned over.

I have one of those after market electric fuel pumps that is about 2 month old.

It's the combination of the fuel pump and tacho that has me thinking it may be a bigger problem

Any ideas?

It soumds like you are not getting power to all this stuff. Check the power wire at the solenoid, the small one that feeds power to everything. It might be loose at the terminal. If that is OK, look at the ignition switch and terminals.

Al

Well I've got it started. Turns out the fuse that always has power had blown. I patched it up with some wire which then blew. I disconected the altenator, wiggled some wires here there and everywhere. then tried the ignition again and the fuel pump worked, but with out that main fuse?
Anyway its not on the side of the road anymore. More investigations to come.

The fuel pump is fed from the switched fuse, not the continuously powered fuse.

Therefore it's probable that with the fault you have somewhere in the car, the voltage dropped to the fuel pump preventing it from operating properly. Now the fuse is removed the voltage has returned to normal.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

So what does the unswitched fuse do?
I still have lights!?

I haven't a wiring diagram to refer to here, but I believe that apart from the ignition circuit, the main light circuits are unfused. They feed from the battery fed side of the fuse.

I'm not absolutely sure, I would like to confirm if I had a wiring diagram but this can be easily proven by removing both fuses and giving them a try.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

It looks like the lights are unfused. The only thing connected to the unswitched fuse is the horn (& interior lights if you have them)
Some of the wiring in my car is 50 years old now so it is not surprising that I have this problem

The lights were both deliberately unfused, so its quite normal. It seems odd, but there you go.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Lights in Oz Minis are left unfused so the candles in your 850 don't both go out at 70MPH and leave ya in the dark.

Older Holdens had a thermal breaker that pulsed the output to the lights if there was a short circuit.
Hillman Imps had no fuses in the whole car- nada, zip.

I run a New Era headlamp relay, it has a 30A blade fuse on each circuit.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Doc,

do you need two of these New Era relays? one for low and one for High?

just looking at this wiring diag and it's showing two...

http://www.ebay.com.au/itm/New-Era-Twin ... 0817257996

There's just one, the ERA relay is two individual relays built into one case.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.