Electrical issues with new loom after rebuild

[Rich997]

Dear all,

Hope some kind soul might be able to suggest likely reasons why lights, horn, wipers are refusing to work following a rebuild.
Although the car is a 61, the new loom (for Cooper Mk1 ...) appears to be consistent with the wiring diagram for 64-67 Cooper S (single brown wire off terminal A on voltage regulator).
So far I've checked connections and earths, with nothing obviously wrong.
Fuel pump works, but I can't power up the lights (Including interior light) or wiper motor.

If anyone can recommend the most likely issue(s) I would be grateful.

Thanks

[Dr S]

You need to find the common link for me it was the brown and yellow onto the regulator from the solenoid. The rubber sleve was on the spade but not the actual spade... I'd just work through step by step and you'll find something that pops it into action

[Rich997]

Still struggling to resolve wiring issues.

Now have working indicators but the stalk is flashing even in the parked position. It was necessary to reverse the wiring on the after market (rubbish) flasher unit to get anything working.

So far the wiper motor, heater motor, temp sender, fuel tank sender seem to be correct.

No horn (confused by the black/brown wire on the stalk loom and how this relates to the purple/black on the main loom)

No lights working

Seem to be getting power to the solenoid and fuse box ok.

Any helpful advice would be much appreciated

Cheers

[Dr S]

At a guess for the horn purple black is live, brown black is a switched Earth? So the horn may be powered all the time and only beeps when connected to earth

[coop12g295]

Horn is live feed and earthed on the column

[Rich997]

The confusion is to not have a black/purple wire on the column loom (indicator look) to join with the main loom ?

[morris cooper]

The Brown/black connects to the purple/black in the five way connector. The steering column must have a good earth to the body for indicators and horn to work correctly

[Rich997]

Thanks for the comment re. Brown/Black connecting to purple/Black.
I did wonder how good the column earth was via bracket to dash or through the rack itself.

Having done simple checks with a multimeter, the earth seems to be ok, but I still can't get the horn to sound.
Also the flasher unit seems to be working on and off now, so presume this is faulty or might have been damaged by shorting.

Any more handy hints and tips will be appreciated.

Baffled by the lights now, all connections seem correct, but no joy.

Thanks

[surf-blue-850]

When sorting out wiring problems, multimeters and test lamps can be misleading. I prefer to use a 'real world' load to check continuity ie a bulb and battery.

[Rich997]

I'll have a go with the bulb & battery method next.

Frustrating to not have found anything glaringly obvious and the seemingly erratic flasher unit might be misleading.

Thanks

[Mini7org]

Silly question but are you running Dynamo/alternator and positive/negative earth?


It sounds more like it could be a earth return fault from a floating (poor) earth so your meter and test equipment will act as the earth return, check your earth points are actually true earth in respect to the battery terminal (resistance should be practically zero ohms from battery earth terminal to all other earth points) But I have no experience on any pre 1980 Minis to point you in a better direction than that.

[Rich997]

Thanks for the comments about earthing.

The system is Dynamo with Positive earth.

Most of the components are new, with the exception of fuse box (looks fine), horn, wiper motor (working).

I've wondered about dodgy earths but there wasn't an obvious bad one.

Haven't tested the resistance with a meter so will look at that.

The wavering issue with indicator flasher is frustrating, all seemed ok apart from the stalk flashing even when in the parked position.

Can't figure out why the horn won't sound (column is earthing but I haven't measured it)

Not sure if this can be explained by a short circuit.

Cheers

[abri]

I assume you've tried running a wire from the solenoid to the horn and one to earth to check if the horn makes a sound? Sometimes the innards on the horns can get stuck (I had this on a Lucas 9H)