Cooperess
Engine off for now. We just want to know roughly how much electrical load (current) there is from each lighting circuit.
Dave2

Engine Off
Battery Volts in the boot = 12.64
Fuse Box Volts = 12.64
3. Parker Volts = 12.4
4. Low beam volts = 11.94
5. High beam volts = 11.86
Earth wires, switch wires, dip switch wires all getting VERY hot especially on high beam

NB Dip Switch, Light Switch & all wiring to lights is brand new along with front VIN wiring loom.

For completeness, is your rear wiring loom new? Parkers, indicators, number plate light, fuel pump, fuel gauge (wiring to tank), interior light all work OK? Try disconnecting the rear loom. Still running the 130/90 bulbs ? You could try unplugging/removing bulb (or disconnecting headlight wires from front loom) in one headlight and see if the problem remains, then swap sides. Clutching at straws now.

_________________
1970 Mk2 Cooper S under restoration

ausdino Rear wiring loom is 1969 original?
Parkers, indicators, number plate light, fuel pump, fuel gauge (wiring to tank), interior light all work OK.
Running the 60/55 bulbs.
Haven't tried unplugging/removing bulb in one headlight and see if the problem remains.

Cooperess
Your voltages look right; it is unlikely that you have major short circuits or faults. The 60/55 bulbs are better for the wiring than 130/90 watts.
I will try my car when it stops raining in Sydney and check the temperature of the wiring. I don't have relays so the 55/50 bulb x 2 current (ie 10 amps) is directly from the light switch. I rarely drive at night but have not had any trouble in the ten years that I have owned the car.
My (wild) guess is that maybe your wiring loom is using cheaper, thinner, low current wires that are meant to switch on headlight relays. If thinner wires are used without the relays the lights will work but the wires will get warm or even hot. Don't panic yet; I might be wrong. (Any other thoughts????????????)
A few Ausmini helpers have suggested fitting relays to run the headlights and this might be your final solution to fix the problem. I will get back to you in a few days but in the mean time try to find any info that came with your wiring loom.
Dave 2

The headlight volts are actually bad. Even 0.5v drop in 12v is a lot.

_________________
1986 Mayfair (998 auto), 1974 S, 1974 Van, 1972 PMG Van

Too many minis

it sounds like it, but I really hope not - I think its from Vintage Wiring Harness - this is their bread and butter

cooperess

I'd like to see what it's like with the stalk dipper switch removed from the system.

Can you disconnect the car side of the blue/red and blue/white wires from the connector on the steering column and (individually) connect them directly to the blue wire that comes from the headlight switch - see if it still gets hot

I think it should still get hot, but ??

_________________
did I tell you that I won a trophy?

If you do this, you will also be drawing half as much current. If its a problem with the loom/wire sizes, they wires should be noticeably cooler with half the load. Simon K - Good idea isolating the stalk dipper switch.

_________________
1970 Mk2 Cooper S under restoration

simon k I'd like to see what it's like with the stalk dipper switch removed from the system. The blinker stalk dipper switch is not connected. The wiring loom I have is for the floor dipper switch.

Can you disconnect the car side of the blue/red and blue/white wires from the connector on the steering column and (individually) connect them directly to the blue wire that comes from the headlight switch - see if it still gets hot. I only have the blinkers and horn connected to the steering column blinker stalk.

Cooperess
I just had a lightbulb moment.
LED bulbs use much less power than normal (incandescent) bulbs AND draw much less current through the wiring.
IF your car has H4 connectors for the headlight bulbs (3 spade connectors at right angles to each other) AND you have removeable bulbs AND IF you don't mind the white, white, white colour of LED headlights then fitting H4 LED headlight bulbs MIGHT solve your hot wiring problem.
Quality LED bulbs cost about $100 a pair but cheap VERY poor quality LEDS cost about $10 on the net. The cheap ones die very quickly but might work for testing.
If you have the H4 connectors were they on the wiring harness when you bought it? .......................
Dave2

So what headlight bulbs were in use during this test?

You mentioned way back something like 130/90 bulbs?? Are they still fitted ? Have you installed relays?? With the new bulbs both high and low beam are drawing much more current than standard....and more than the standard switches, wires etc are designed to handle. P=I squared R .. More current = lots more heat.

If not, then everything seems to operating entirely normally. Install some standard bulbs and check what happens.

Cheers, Ian

PS Before entering ANOTHER unknown (LEDs) just get a couple of cheap standard bulbs....

Dave Dobeson I am using halogen H4 60/55W. Should I be using H4 NON halogen bulbs?

Changing to led bulbs may cure the symptoms but may not solve the problem

_________________

timmy201 Your right I do need to solve the problem. I am sure there are other round nose Mini owners who are running H4 halogen bulbs and not having the same problem.

1071 S So what headlight bulbs were in use during this test? H4 60/55W Halogen.