Total electrical failure - 1750GTV registered race car

[mbakermarco]

Hi there

I'd been working on the car in the air filter area and went to road test the car to find a dead electrical system - I'm not very good with auto electrics ! - Any ideas ?

Battery charged and tested as ok
starter motor is getting current
Both sides of isolator switch have current
Red wire to starter now has new connector

I have no horn (but I can take a tablet for that !) No indicators / headlights / dash lights / ignition lights, nothing !

And ultimately, no start.

Any inspiration would be gratefully received !

Mark Baker

[colcol]

Check earth wire from battery, check that fusebox is getting 12+volts, and ignition switch is getting 12 volts and if it is see if the 'ignition on' wire has some juice, double check that isolator, they can be a source of all sorts of problems, just get a 12 volt test lamp onto the battery and work your way through the car, best of luck, Colin.

[mbakermarco]

Thanks Colin - have been using test lamp and have a new multimeter - not yet used - thats tomorrows job - thanks again - much appreciated.

Kind Regards

Mark Baker

[MD]

Mark,
Just adding a little to Col's advices.
Those old ceramic fuses develop two problems. 1 A lack of tension so that there is insuficient current flow to drive a circuit. 2 Occasionally a verdigrease oxidation that causes a high resistance connection.

So whether the fuse box is your source of problems or not, it is a good idea to go through and clean up every connection in the fuse box, including the tips of all the fuses with a "Scotch" abrasive cloth. This should be followed up by a tiny smear of vaseline on all contacts. The third thing to do is re-tension all the connectors by squeezing them together a little.

Be sure you place all the correct fuses back to where they were originally.

Just remembered to say that a circuit may show it has 12 volts. It may even make your test light glow. However, if there is a poor connection or a high resistance joint in a connection, there will be a serious inability of that circuit to deliver a good working voltage/current to do the job for what the circuit is intended to do due to such connection faults. So don't be fooled thinking just because it shows 12 volts and a light glows that all is well. Most of the time it is well but if the problem persists, you need to examine such circuits more thoroughly.

As for the horn circuit, get that seen to asap as you never know when you will need a good horn.

[colcol]

Absolutely correct MD, whenever the 33 has a problem, the first thing to check are those Stupid, Stupid fuses, the old type ceramic fuses where good, as they wouldn't melt like the new plastic ones, when they carry a fair bit of current like 25 amps, they get a bit warm, when they have a poor connection, they get hot and the plastic ones melt, clean up all the connectors that hold the fuses and clean the fuses themselves and push the 2  fuse holders together to ensure a tight connection, and when you install the fuse, put it in upside down, that is the fuse wire pointing down, and when installed turn the fuse 180 degrees, as sometimes pushing the fuse in, with the fuse wire up, dislodges the fuse off the tang and you get a poor connection, Colin.

[mbakermarco]

Thanks guys - much appreciated.

[colcol]

Apart from Alfa Romeo electrics, did you find the problem?, Colin.

[mbakermarco]

Thanks again guys - I wimped out in the end as I was getting nowhere, and got Paul Young out (who I bought the car from) as he is an auto electrician. He quickly found a broken wire to the alternator, so all is well now ! So I'd recommend Paul if you have any problems of an electrical nature on your car, Alfa or otherwise ! I was embarrassed that I didn't find it though........

[MD]

Ha haa, I know Paul very well but I didn't know he was moonlighting as the Wizard of Oz. 

Mark you originally reported a "No Start" problem so I am starting to think that perhaps Paul does have latent Wizard talents cause that would come in handy to get a car to start that had an alternator wire problem. That's because the two are about as related as corncobs and soccer boots.

You see, the job of the alternator is simply to top up lost energy from your battery. If your battery was fully charged as you said it was, then it was ready to do its job of cranking the motor and firing up the ignition and fuel systems. In the short term you could tie the dog up to the fence with the alternator wire and your car would still start and run.

I know Paul has a sense of humour and I hope you do to. Paul needs to explain to you perhaps in more detail what the actual problem was. However given that this has been part of a private business transaction, please don't feel obligated to discuss it further. Everybody will understand.

All silly perspectives aside, now that your Alfa is running, go out and have yourself a ball.

Cheers.

[colcol]

A broken alternator wire is not that hard to find,....about 20 years ago i went over a railway line and the 33 stopped, no power nothing, no instrument lights, completely dead, after about TWO HOURS i found the wire had fallen off the back of the alternator, so obvious, but i kept checking the ignition switch, fuse box, battery, starter motor, etc until i looked in the right direction, those master switches for the battery can be a source of problems, the 2 plates can get corrosion on them and refuse to make [good] contact, Colin.

[mbakermarco]

The alternator wire that was broken was the main feed apparently, affecting ignition and everything else besides, in short (no pun intended) a total electrical failure. Paul was surprised not to find this main feed wire either connected to the battery or starter motor, but instead to the back of the alternator. As all I had done since parking the car in the workshop/shed had been working on the other side of the engine compartment, on the air filter arrangement, fitting trumpets and socks, I thought I'd affected something with my ham fisted tinkering on that side !

I know basically what an alternator does, but am looking at my Labrador, wondering if using her as suggested would be more eco - friendly ? If nothing else it would tire her out and stop her running around the house when she has a mad five minutes at about the same time each day !

I must have a sense of humour, as I started playing with Alfas after I'd spent a good few years with LOTUS cars, which as I'm sure you all know, L O T U S stands for Lots of Trouble, Usually Serious !

Thanks again for your input guys !

[MD]

Paul was surprised not to find this main feed wire either connected to the battery or starter motor, but instead to the back of the alternator.

Me too. 

That explains everything.

[alfafarm]

Hi Mark   Thanks for lotus translation we called elans sunday cars as you spent mon to sat screwing all the bits back on that fell off on the previous sunday. I could fill a book on the various bodges perpetrated on Alfas by so called mechanics I have seen.eg one cent coins with holes drilled for flat washers Regards john