Practically Classics Forum

heres the scenario guys and gals. 1965 singer gazelle 1600 had a problem with loose igntion switch finally fell out and shorted some wires -result mess of melted wires from switch to solenoid and elsewhere. Have replaced the main wire to the solenoid but none of the others and engine seems to start and run as normal, but after a couple of miles the wiring to the fuse box gets hot. The ammeter is disconnected following the meltdown and it is not shown on the wiring diagrams i have .
There is a spare connection behind the solenoid -should this have a wire to it from somewhere ? Where does the ammeter fit into the wiring? Any help would be greatly appreciated.A decent wiring diagram would help enormously !
Many thanks as always John B

When you took the ammeter out of circuit, how did you join the cable ends together? That cable carries up to the full (c.28A) output of the dynamo and unless you make a continuous, soldered join with no restriction in the area of the cable, that could be responsible for other paths - which shouldn't be exposed to that sort of draw - becoming hot.
Ideally, there wouldn't be a join at all, I'd always replace the battery positive with a shorter piece of cable of the same gauge, going directly from the battery to the solenoid. Without the ammeter in the cable, there's no reason to have it inside the car.

Thanks for that John-this could be the root of the problem . The wiring was so bad that I could not tell where the ammeter was wired in to the circuit. I have replaced the wires to and from the ammeter but they are waiting to be connected -any idea where on a gazelle ?

An ammeter is usually connected in series with the dynamo's output or, in other cases, in series with the supply lead from the battery's non-earthed terminal to the block of terminals at the solenoid so the easiest way to establish where it's supposed to have been connected in your car would be to look for either of these thick cables entering and exiting the bulkhead via a grommet (or one each) somewhere in the engine bay not too far from the back of the instrument panel.

The symbol for the ammeter in the car's wiring diagram would be this: but if it's been added as an accessory at some later time, then there's maybe not one on there. I have a feeling that only the lower spec Minx would have come without the ammeter though, the Sunbeams, Humbers and Singers of the same period coming with an extra gauge or two.

Unless originality is of paramount importance to you, I would advise that you replace the ammeter's movement with a voltmeter ("battery condition gauge") since they're an awful lot safer than bringing full charging current to the dashboard and are connected in parallel with an ignition load (say by an earth lead and a switched supply from the ignition switch or fusebox).

John B wrote:...The wiring was so bad that I could not tell where the ammeter was wired in to the circuit.....

Given the importance of electrical safety, might it be worth your while considering the replacement of the entire section of the loom which suffered as a result of the problem? It'll be the neatest as well as the safest way forward.

the gazelle had a round dial with 3 gauges at 60 degree spacing and one of these is the ammeter. The main loom seems ok the only wires that burned out were the thick wire from the ignit switch to the solenoid which i replaced and a thin wire which went from the ignit switch and disappeared towards the ammeter behind the dash. Access is poor and visibility is also bad behind there but with a torch and contortions i have replaced the wires to the ammeter but not connected it in and all else looks ok surprisingly . There was another thin wire which went through the bulkhead from the switch i think . could this have gone to the spare wire connector hiding partly behind the solenoid? We have 2 wiring diagrams and neither show the ammeter connected or these wires which burned out so it seems you are on the right track .

Cheers again JohnB