Junior cutting out

Friday afternoon, on my way home from work, my junior just died. No power to anything at all, not even the radio (which draws power directly from the battery.

Got the car towed home, tested the battery, it sits at 12.5 volts, more than enough.......

Any ideas ? I'm stumped

Earth strap? Gotta be one of the first connections if the radio isn't working.

Is there a "main" fuse covering everything?

wrinx

Checked the earth, all is OK there.
All the fuses are OK as well, but I have not had time to go through all the electrics with a Multimeter yet.
I suspect a massive short on the body somewhere........
Just goes to show you, earlier last week I mentioned to someone that I may sell the junior, since I have too many cars. The car heard me and is now punishing me.

If the car happened to be a J-body GM, I'd bet my entire fortune on the problem being an alternator that has packed it in. Since it's an Alfa, it could be almost anything.

Good luck locating the gremlin. And yes, they do listen to us and react accordingly.
--Toronto

Strange enough, I also now suspect the alternator has given the ghost........difficult to test though, as I cannot get the motor to turn over.
I should still have power to things connected directly to the battery, like the radio.
Nothing,Zip,Nada, f-all

I had a problem similar on my Junior a couple of years ago, problem turned out to be the battery cable wasn't clamped tight enough to the terminal, I had to modify the clamp with a hack saw to allow a tighter fit, no probs since. Might be worth checking.

Originally Posted by Eric Metz

Checked the earth, all is OK there.
All the fuses are OK as well, but I have not had time to go through all the electrics with a Multimeter yet.
I suspect a massive short on the body somewhere........
Just goes to show you, earlier last week I mentioned to someone that I may sell the junior, since I have too many cars. The car heard me and is now punishing me.

If there was a massive short to earth(Body) then I suspect your battery would be as 'flat as the proverbial tack'...
An open circuit would be mor likely IMO.

I found a loose power cable, that should connect to the starter motor (quite a thick red cable), but there are no burn or short marks on the copper. I cannot trace the other end of this cable, and do not want to re-connect before I know where it is supposed to go.
Excuse my ignorance here, but the starter has connection to :
1- Ignition switch
2 - Battery terminal direct
3- In some of my cars, a connection to the alternator
4 earth

Am I correct ?

A thick red wire would usually be the connection to the battery but not knowing your car........bit of strange one if you've alreay checked that

Why can't you trace the other end?

wrinx

I could not trave it as it goes into a loom with quite a few other wires, and this loom disappears inbetween brake pipes, fiuel lines, etc. I need to spend some serious time on this, but I have not got that luxury at the moment, I am swamped at work.
I did manage to speak to a good classic car mechanic this morning, who advised that, judging from my description, I have a bust battery or ignition switch.
This weekend I will take out the airfilter assembly, so that I can actually see what I am doing, and test the connections with a multimeter.

Still don't know where the red wire goes to ??

I could not trace it as it goes into a loom with quite a few other wires, and this loom disappears inbetween brake pipes, fiuel lines, etc. I need to spend some serious time on this, but I have not got that luxury at the moment, I am swamped at work.
I did manage to speak to a good classic car mechanic this morning, who advised that, judging from my description, I have a bust battery or ignition switch.
This weekend I will take out the airfilter assembly, so that I can actually see what I am doing, and test the connections with a multimeter.

Still don't know where the red wire goes to ??

.

Eric

There's two types of alternator on the junior - one with an inbuilt regulator and one with an external reg.

If you have a built in regulator then you should have a big fat red wire that goes to the battery, and a thin green wire that goes to the ignition switch via the charge light.

If the regulator is external then you'll have the two extra wires you mention on your other cars. On the junior the regulator is a shiny metal box about 2 x 1 x 1 inches, mounted just in front of the battery.

If the loose red wire you mention really is thick (about 6mm or more copper diameter) then this wire must definitely connect to your positive battery post. It's a straight through connection. You can jumper it to test.

You need to double check - is there a thick red wire already properly connected to the big terminal on the alternator? And is the other end connected to the + on the battery?

You dont mention the charge light at all - does it come on? I'd check the bulb (on cost/benefit) before changing the alternator. A failed bulb will always prevent charging.

You also need to check the connections at the battery posts and the earth to the car as mentioned earlier (eg do you get 12v between the + and the engine?)

And finally (or should it be firstly?) you need to reaffirm what you mean by 'completely dead' do you not get even a faint glow from the sidelights? When the lights are on do you still get more than 12V across the battery?

I disagree with the suggestion that its likely to be the alternator cos its an alfa - I believe its more likely to be an earth or a bulb for the same reason.

Gausie

Thanks for the info Gausie

Let me clarify.
The car went dead......no power whatsoever. as if the electrical system was removed.
The car cut out on me at about 60 km/h, and that was it.

If the battery is at 12.5V under load and the earth is good, then there is a break in the main wire or one of it's connections that feeds the electrical system. My guess would be either at the starter or at the back of the fusebox. I'll check the wiring diagram when I get home. What year is your Jr?

Yes, of course. 1972!

The diagram shows that your Jr. is powered by a single 10ga red wire from the starter to the fusebox. I check for battery voltage at the starter. If less than the voltage at the battery, I'd suspect the positive battery cable/connections. If the voltage is okay at the starter, check the voltage at the largest red wire on the back of the fusebox. If less than battery voltage, there's a problem with this wire or it's connections. If voltage here is okay, back to the drawing board.
If you'd like a color wiring diagram for your Junior, PM me your address and I'll email it to you.

Originally Posted by papajam

Yes, of course. 1972!

The diagram shows that your Jr. is powered by a single 10ga red wire from the starter to the fusebox. I check for battery voltage at the starter. If less than the voltage at the battery, I'd suspect the positive battery cable/connections. If the voltage is okay at the starter, check the voltage at the largest red wire on the back of the fusebox. If less than battery voltage, there's a problem with this wire or it's connections. If voltage here is okay, back to the drawing board.
If you'd like a color wiring diagram for your Junior, PM me your address and I'll email it to you.

Thanks for this.....I think this is exactly where the problem lies. The single red wire you mention must be the loose one I found. I could not find the other end, but it could very well be the connection to the fusebox, as it disappears into a loom that goes "where no man gone before".