Lighting issues

NEG

True Classic
Does anybody have an EU wiring diagram for a 1978 1300?

I have an odd issue with the lights on my Lido.

First issue is the the headlight flash function. On my car flashing the headlights flashes the dipped beam and not the full beam circuit

Second issue is whenever the fog lights are switched on they disable the dipped and full beam lights. Turn them off and they work again. They should AFAIK work independently of the headlight circuits.

I found the relay below was none functional and fashioned a quick repair to the coil wiring hoping this may be related somehow, instead it fixed the rear demister! Oh well!





I also noted the connector below plugged into nothing and I’m wondering what it could be for.



Any ideas gratefully received!
 
Hi Neg
I have the same connector with nothing plugged into it. It's just below the fuse box in the drivers side.
I have no idea what it's for as I can't find that colour combination of wires on any wiring diagram.
Will be interested to find out what it's for.
Andy
 
This really does not answer the question about the mystery electrical plug, but keep in mind that the wire harnesses were made to fit multiple options, regardless of the particular car having them or not. For example, the air conditioned cars have a different heater box with a blower motor that uses a different connector plug. So rather than making two sets of wire harnesses (one for AC and for non-AC), they simply had redundant wires with both types of plugs - and left the unused one laying around. In your case I'm not sure if the plug you pictured is for that, but just know there may be unused connectors left laying around on purpose.

About the lighting issue. Again, I don't have a definitive answer. But corrosion is usually the source of such problems. I'd start by cleaning all of the grounds, connectors, contacts, etc, throughout the related systems. If the problem still persists then get out the electrical multimeter and start checking for continuity and excess resistance in all of the circuits.

Wish I had better answers for you, but hopefully this gives something to consider.
 
Sorry I have no definitive answers but hope this helps:

I believe the standard wiring is for the flasher to operate the main beam, but I do recall in the dim and distant past doing some rewiring at the column switch to make the mains rather than dipped lights flash on one of my cars, it may have been on a 128 3P, which has twin headlights. Maybe someone has swapped some wires at the column switch. I would have a look there first.

The fog lights are a bit of a special option and I don't think I've ever seen a factory wiring diagram for them. However I have fitted fog lights based on the circuits of later Fiats, such as the Uno. The Uno has an arrangement of cut-out relays such that the fog lights go off if you select main beam, and the front fogs are enabled by switching on the dipped beam.

These arrangements stem from the UK regs, which basically say the fogs should not be on with main beams. It seems you have a similar but reversed arrangement on the Lido, but it seems odd to kill both the dipped and main beam. I suggest you trace the wiring and find the cut-out relay(s).​

Looking at the relay holder and the wire colours, white/black is usually for a "switched earth" such as the door switches or the "handbrake on" switch. The relay is powered by the violet/black (or is it black/violet?) and the relay supplies power to the red/black wire when operated. More tracing of wires is needed!

I expect all your relays will be getting tired now. If you want to preserve originality you can still get the old school metal can relays from Auto Electric Supplies or evilBay. Search for Lucas SRB.
 
Last edited:
Fog light issue sorted, just the flash to work out now.

Fog light switch....

Incorrect



Correct



Simple but confusing!
 
Hi Neg,
Just checked my switch and it is wired as per you incorrect picture however I don't have foglights fitted. The PO removed them.
Interesting. Two cars wired incorrectly.
Andy
 
Or by design maybe? Bit odd all the same, thought having the fogs on as well as dipped beam would be normal operation.
 
It seems the flash issue is by design. I’ll post a diagram later to help others but essentially the column stalk flash switch shares the same spade connector in the steering column multi block connector as the dipped beam switch. IE they are wired in parallel. The wires, both grey with a red stripe, run to the column switch but terminate in two different places. These are fed from a green wire into the same connector block that has 12v on it when the master light switch is set on.

I’ll have to remove the column switch assembly to determine which grey/red wire I should the flash wire and then splice it into the main beam wiring.
 
Back
Top