Austin Ten Four Chrom Rad Wiring

[austin10_4]

Hello the everybody.
Some of you may remember me from around this time last year with my dreaded head gasket problems?!?!

Anyway, the english weather has finally turned for the better and i though it was high time i cranked the shaft once again to hear her familiar chugging.

All was well and good, that is until it got dark.

I, naturally, put the lights on, only to be greeted with one sidlight. I replaced the bulb, nothing happened. I replaced it again, still nothing. Putting this down to bad luck, i replaced it with the one from the drivers side that was working, still nothing.

This lead me to the dreadful and time consuming task of identifying the 74 year old wiring (its still original!!)

Anyway, i then discovered that the junction box which houses fuses aswell as a multiplex of wires was becoming extremely hot. This points to a short circuiting problem agree?

Thats what i thought, so i proceeded to disconnect the lights and try them individually. Neither of the lamps now work, and the junction box is also becoming very hot.

Just to add confusion to the matter, the polarity seems to change if you change a fuse?!?!?!

And to make it even more complicated- the ignition has reversed. I think it has anyway, as the ignition warning light comes on when you turn the key the opposite way you normally do if that makes sense?

Something has gone horribly wrong here, and the wiring is vaguely similar to a rats nest.
I come seeking advice from any electrical masterminds that may be here.

Regards, Austin10.4

 

[Bruce Bowker]

Wiring is as much fun as a spinal tap. Any chance the battery is backwards? If wires were shorted I think they would smoke soon enough. The heat though indicates too much current being drawn or a short. Are grounds all good?

Any chance you might know in what car Detective Foyle of Foyle's war rides?

Bruce

 

[Bruce Bowker]

Found it.

1937 Wolseley 14/56 Series II

 

[philman]

I have a wiring diagram for the Austin 10/4; I am unsure of the model year. If you pm me your email address I can send you a jpeg image of it. It would be too large to add to a post.

 

[philman]

The wiring diagram shows another fuse in the nearside headlamp for the dipping solenoid. Power to side lamps and the ignition warning lamp seem to come from the switch box on the instrument panel through different terminals. Maybe a short in there?

 

[austin10_4]

Cheers for the heads up guys. Obviusly the time difference between the UK and US is going to mean long reply times!

Anyway, i have the wiring diagrams at the moment and to be honest i cant make head nor tail of them.

I see that the sidelights do go straight to the switch, i shall have a look inside the instrument panel to look for bare wires but i feel it may be simpler to bypass the old wires for new ones :frown:

Also in regards to the battery, yes it is round the correct way as everything else is working correctly. It is only the side lights.

Ill keep you posted,
Regards.

 

[DrEntropy]

If the iggy light comes on after the switch is off, the generator is a likely suspect. No idea what shape yours is in but a new set of brushes is all it takes with mine to get back to normal. Clean the commutator with a kitchen type plastic scrubbing pad, 3M "ScotchBrite" (dark red) works very well.

The wiring can be getting hot due to high resistance. I'd be for cleaning all the grounding points and all connectors. A short would result in copious SMOKE release. Your description sounds more like a resistance (read: corrosion) problem.

 

[austin10_4]

None of the wires get hot at all, just the relay type bit.

Let me give you some more details:

It is the ignition light that comes on but only when the sidelight switch has been on for over 3/4 minutes.

So, you turn the switch for the sidelights, they dont come on, but then the red ignition warning light comes on (lights still off) and then when you turn the key to power the coil, the red light goes out. The only way to correct this is to disconnect the battery.

The "relay" im referring to is next to the auxillary and main fuse box, and this starts to get hot as soon as the red ignition light comes on (about 3 minutes after turning the light switch)

The main headlamps are still working fine, but the car is currently out of MOT and will fail :frown:

Regards.

 

[DrEntropy]

Is this "relay" p'raps the voltage regulator? And the ignition light behavior still sounds like it could be dynamo brushes. But it also sounds like bad earthing points is a possibility, and the light circuit could be grounding back thru the iggy light or circuitry.

Whatever it is, you've got ~something~ weird goin' on! Have you tried running a separate wire to the light as a grounding test? And a "test light" would help you poke around and tell if the wires are passing current & where it stops (connectors, etc.).

 

[eschneider]

I think Doc's spot on. Corroded grounds and poor connections will give you no end of grief.

Even if it's not the ultimate source of your problem, bad connections will make your life difficult. Spending a couple evenings cleaning the grounding points, the engine ground cable connections, and cleaning the electrical connections will make life dramatically easier, and will reduce the resistance through all of the electric circuits of the car.

Once cleaned, most mechanics use silicone grease or "kopr-shield" to keep them clean. Everyone has their favorite.

Heat = high resistance. Resistance requires more current to operate a lamp, coil, whatever. Worse, resistance increases with heat. Enough heat and your wires will melt. Usually its connectors and grounds that cause resistance.....

Current load from high heat would be greater if this is a 6-volt system?

if the (first) inoperative headlight and funky sidelight share the same ground.....?

Regarding polarity - your generator may need to be re-polarized?

The red light should come on when battery voltage is different than generator output when the key is "on". If it's illuminated with out the key, then there is some current flowing through the switch (worn metallic particles inside the switch?) or through the generator circuit (bad regulator?) when they're supposed to be "off"

Dunno 'bout Austins - but Morgan lamp circuits run directly from the regulator, and are un-fused. Brown and blue heavy wire going to the lamp switch. There could be a common denominator in your car at the regulator?

Early regulators had "points", which may be stuck after some period of storage.

You mentioned a "main" and "auxilliary" fuse box? Is all the wiring original? I would have thought the car had a 2-fuse lucas fusebox.....?

 

[austin10_4]

Hi everyone, thank you for your replies

An update for you:
I have checked this relay bit and it appears that when you touch it, you earth the system which then causes the red light to illuminate for some reason. Easy answer- dont touch it and its fine!

However, there is still no power going to the sidelights. They are on the same wiring as the main headlamps, and i have replaced the wiring that i can see.
However, there is still definitely no power going to them, despite the ammeter reading says it is drawing 2Amperes.

I have checked and double checked the light fittings, all seems normal.

And yes, i have checked the bulbs :wink:

 

[Bruce Bowker]

Regarding the relay - is it an actual relay? A switch relay? If so are the contacts clean and making full contact when closed?

A relay trying to shut but can't quite make complete contact can get hot and burn.

Bruce

 

[austin10_4]

Ive fixed it, cheers guys!

It was the grounding points that was the problem. Now the lights work, all of the other problems have disappeared. Now its out with the WaxOyl to get her ready for summer.

Thanks to all of you for your input

 

[DrEntropy]