6 replies to this topic

[Down under Luke]

I need help please from anyone that understands or might just have an inkling about electrics in a Mk1 Mini.  The previous owner has taken it upon himself to do a lot of the wiring which all seems ok but, as of today it all stopped working. I built a new dash for the car, re-wired it as the previous had been and put it back. Car started, all gauges worked but then for no reason, everything stopped. No power to the dash at all, nothing to the indicator which isn't even part of the dash set up! 

 

I have checked fuses, i have checked connections, grounds etc but can't find anything that would have caused this. I have included a picture of something that i do not know the name of. The  previous owner had really beefed up things on the electrical front, extra fuses, larges wires and this...thing. One of the connections that ran from this part (picture) ran all the way to the start button on the dash but now the same connection has no power.

 

I am sorry if i sound vague but i really am at a loss and i hate the electrical side of things.

 

Thanks in advance.

Attached Files

•  mini elec.jpg   38.98K   5 downloads

[ace01]

That looks like a later style starter solenoid.  Check you have power to the cable that comes from the battery, the one with the smaller black wire and the yellow terminal.  If so follow the source of power to the dash from there.  If not, check your battery/connections from the battery.

[KTS]

do any circuits work or have have you no electrical power at all ?

 

circuits that should be permanently live include headlights/sidelights, hazards, horn and interior lights, so check if any of them work

 

if nothing at all works: check the battery itself, and the terminals connected to it. check whether the previous owner fitted a fuse to either of the battery cables 

[Down under Luke]

Ok, i have added to the picture to help. I have constant power to the terminal circled with the red. I have no power to the terminal circled in blue and last but not least, the green arrow is to the terminal wire that i have tracked back to the starter button, this has no power and i believe it used to. 

 

Would it just be a case of buying and fitting a new solenoid?

 

I have checked the fuses and they all seem ok too. The previous owner had fitted not just an aftermarket fuse box but also fuses before this in the cabin to allow for double protection. 

 

 

 

 

Attached Files

•  mini circuit small.jpg   40.18K   3 downloads

[KTS]

the solenoid is a switch that's used to provide power to the starter motor.  the wire from the starter button should provide 12v to the solenoid which will close a contact within it and allow the power from the cable coming from the battery (circled in red) to flow through the cable circled blue, which i assume goes to the starter motor

 

you should be able to check the solenoid is working by using a short length of wire to connect between the post where the battery cable is fixed and where the wire from the starter button connects.   

 

MAKE SURE THE CAR IS NOT IN GEAR IF/WHEN YOU DO THIS as if it is working, it will engage the starter motor

 

if the solenoid is working then you may have a fault in the wire between the starter button and the solenoid, so check if you have 12v at the solenoid on the wire from the starter button when the starter button is pressed.

 

if that checks out, then check if you have 12v on the other wire at the starter button.  if you do, then possibly the starter button is faulty.

 

if not, then you'll need to figure out where that wire comes from and check 

 

there's wiring diagrams on the forum you can refer to for help you diagnose 

Edited by KTS, 30 October 2019 - 09:38 PM.

[Cooperman]

If you have lost power to the fuel gauge and the indicators, check the 35 amp fuse which is the top 'master-fuse' in the original fuse box on the RH side of the engine compartment towards the back of the engine bay. It is the fuse which controls a lot of circuits and is ignition switch controlled. If that fuse blows the charing warning light can come on as well.

 

Fit a new 35 amp fuse and see if it all works again. If the fuse was blown and blows again you need to isolate which circuit is causing fuse failure. Remove each of the connections on the bulkhead side of that fuse in turn and fit a new fuse. When you find which connection, when removed, causes the fuse to be OK, you will have isolated the defective circuit. It might be the fuel gauge, for example.

 

If you have an original BMC Workshop Manual you could do the initial investigation from the circuit diagram.

[62S]

Check that the solenoid itself is properly earthed and the connections on it are tight.