Wiring

[Swampy]

Afternoon all can anyone suggest what's gone wrong getting ready for the big mot I've lost indicators wipers heater and horn fuses all good. time to put the kettle on. Regards swampy

[geoberni]

indicators wipers heater and horn

Well (unless someone has changed the wiring) that's a mix of the permanently live fuse and the Ign Sw fuse. So either both have gone or a fuse is unlikely.

Just because the fuses are OK (checked with a meter or just looked for the wire through the glass), doesn't mean the contacts are good.

It's a bit like when the TV remote stops working and spinning the batteries around suddenly brings it back to life....
Clean the contact surfaces.

[Swampy]

Thanks for your reply have tried all of mentioned apart from testing the fuses with a meter every thing is clean. Regards swampy

[geoberni]

Well the Horn is on the left of the Red Line from the permanent live fuse, the other 3 items are the coloured in wires on the RH of the red line.
There is no common point of failure for all 4.
You should also be having problems with the Brake Lights, Fuel Gauge and Oil light amongst other things, or haven't you looked at those .....
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[Swampy]

Evening thanks again yes no oil light or fuel gauge but fuel gauge never has worked.that was on the list a new unit has been fitted. Up till now everything was working fine starts no problem will try again tomorrow thanks again. Swampy

[geoberni]

Evening thanks again yes no oil light or fuel gauge but fuel gauge never has worked.that was on the list a new unit has been fitted. Up till now everything was working fine starts no problem will try again tomorrow thanks again. Swampy

Seems to me your wiring is a bit of a mess then.... Is it still the original 60-70 year old loom it was built with?

[Swampy]

Afternoon yes it's all original and as far as i can tell looking not to bad. Today I've checked all connections cleaned all the terminals at the fuse box fuses are all new and working cleaned all earthing connections and still nothing. Engine starts first time no problem have only red ignition light on that goes out and all the main and side lights work. It's like a switch been turned off .my other half says get auto sparks not yet. Regards swampy.

[geoberni]

Well, it just needs checking out with a multi-meter; if you're not confident/competent with one, then you need someone who is.
The circuitry is about as basic as it gets.
You could try posting a photo up of your wiring at the Fuse Box area and get a second opinion on how good or bad it looks....

[kevin s]

I think they all are earthed via cables, possibly to a common point ?

[Swampy]

Evening ok thanks for your reply I'll try tomorrow i think it's that C word shopping tomorrow .regards swampy

[simmitc]

Indicators and brake lights are earthed through the lamp clusters to body. The horn has a constant supply and earths via the horn push on the steering column, so I don;t think that it can be a common earth.

[kevin s]

The process for this is fairly simple and needs to be methodical.

1. From the wiring diagram identify the live feed to each of the affected components.
2. for each component Using a multimeter (or even better a 12V 5w test light) connected between the live feed above and a good earth check you have power.
3. If you do then it's the component or its earth.
4. If you don't using the wiring diagram work your way back along the circuit to the battery checking for power at each accessable connection until you find where power is present, the break will be between this and the previously tested point.

I suspect you may not have common fault but perhaps a couple of seperate ones theat have occurred by coincidence or there is a trauma somewhere in the wirin which has damaged multiple circuits.

[Swampy]

Morning thanks again for your help I'll look at it later today. Regards swampy

[Swampy]

Morning again please find photos of the fuse box if any help thanks again everyone. Swampy

[kevin s]

As geoberni pointed out it can't be the fuse box, the horn and other items are on differnt fuses and other things on the same fuse are still working, you realy need to set a aside a couple of hours and methodicly go through each issue.

[geoberni]

We can discount a 'Common Earth', there isn't one.

The reason I asked about a photo was to establish a baseline. From the photo, we now know that...

It's a latter car with plastic insulated wiring, not the rubber & fabric of the early ones.
The Fuse Box makes it 1963 or later, so it has individual Blade terminals, not just wires under a screw head.
From the Colours of the wiring, we can see that someone hasn't mixed them up in the past, cross connecting the different wires at the fuses.
The right number of wires appear to be in the right places.
The Wiring appears to be in good condition.
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There's at least 2 problems here, I can see you've cleaned the fuses, but those Blade Terminals don't look to be particularly clean.
Have you cleaned the fuse terminals and not the Blades on the wiring???

You've not mentioned Interior Lights working or not??
But there's only 2 Purple wires, one for Horn, one for Interior Lights.
The 3 Green outputs spilt to cover:
A - Stop Lights
B - Indicators
C - Everything else

That's about as much as I can tell you, but you can see there is no common point of failure.
I have concerns that there are other things not working which you haven't told us about.

I appreciate that many people don't have a clue about basic electrics, but this is not a complex problem for someone with a multi-meter and a bit of an understanding of how electricity works.
It's a 5 minute job .... if you know what you're doing. If you don't, it's time to find someone who does.
I don't subscribe to using a Test Lamp for fault diagnosis, because if you don't understand what you're doing, even using that can confuse.

[kevin s]

The reason for using a test lamp is if there is a high resistance a multimeter may read 12V but put some load on the circuit via a 5W bulb and the voltage drops away.

[geoberni]

The reason for using a test lamp is if there is a high resistance a multimeter may read 12V but put some load on the circuit via a 5W bulb and the voltage drops away.

I understand that, I was an aircraft electrician for decades, I have vast experience of strange faults, including induced EMFs and circulating/floating earth faults, but as I said regarding the test lamp...

if you don't understand what you're doing, even using that can confuse.

[Swampy]

Good afternoon Have cleaned all the terminals but will give them another go. As mentioned before the main lights are ok and side lights interior light works but only on the switch. I have been looking at other photos some have three wires at the switch I've only got two not sure if this right or not it has door switches and a brown wire running from one side to the other behind the dash no sign of any loose wires about. Regards swampy

[geoberni]

As mentioned before the main lights are ok and side lights

Not relevant, they are supplied direct from the battery via the RB106 Control Box.

Don't get hung up on the door switches, the car clearly has a lot of small electrical issues, and you're mentioning them piecemeal.
You don't seem to have the level of understanding to take this any further yourself; your other half now has my full backing...

...my other half says get auto sparks