ignition warning light

[patrickhowell]

I have a 1971 Traveller, fitted with an alternator. Recently, the car broke down, and the condenser was found to be faulty. After replacing it, the ignition light in the speedometer stays on, even when the key is withdrawn, any idea as to cause? The light goes out after the engine is started, and the charging system seems to be working normally.
How do you get access to the back of the speedometer, as there seems no obvious access panel?

[mogbob]

Patrick
What type of Alternator do you have fitted. Do all the Alternator wires appear clean , sound and firmly attached.
Fan belt not slack.
You say the charging system " seems to be working normally ".Does this mean you have checked it with a Multi meter and the battery is showing between 12.6V to about 13.5 V.
Could be one or more diodes in the rectifier pack have failed but let us know the status quo before we jump to conclusions.

Speedo removal.( Battery disconnected ).Looking at the speedo there are two retaining screws , one at the 3.00 o'clock
position and the other at 9.00 o'clock position In the passenger cardboard glove box ( and drivers side ) there are two small circular cut outs. Just " slacken " these screws slightly , to allow you to withdraw the speedo towards you , holding the rim.
If you remove the screws completely , dropping them inside the car , somewhere ..do be prepared for hours of endless fun
dismantling the dash , retrieving the screws and putting everything back together again !!
Bob

[oliver90owner]

The bulb current is required to energise the alternator at start up (basically feeds the rotor coils to produce the required magnetic field. It should not be in any circuit while the ignition switch is in the 'off' position. The condenser replacement (in the distributor, presumably) should not have affected the alternator.

[patrickhowell]

There are no visible markings on the alternator to indicate the manufacturer, only a serial number. A voltmeter is showing 13-14 volts charge with the engine running. No visible damage to the wiring, I am wondering if it could be a problem with the ignition switch, which is of the steering lock variety? Thanks

[patrickhowell]

I would add that, with the ignition switched off, the right -hand coil in the voltage regulator engages automatically when the battery is connected. Thinking that the old regulator must be faulty, I replaced it with a brand new one, but the same still happens. Voltage is obviously still going through the ignition key switch, as disconnecting the top wire to the switch causes the offending ignition light to go out.

[myoldjalopy]

Thats a bit odd. An alternator doesn't need a separate voltage regulator/control box...........

[mogbob]

Patrick
A suggestion .. at the top of the Electrical Section on the Forum are two Dynamo / Alternator " stickies " one is a before and after wiring diagram ( switching from Dynamo to Alternator ) and the second is a Moss Motors video on how the two work and
wiring is run for both. It deals with the fact that the control box / regulator is not required when the switch is made.
Armed with a note pad record what colour / size wires are connected to what on your vehicle. In doing that you may solve the issue or at least enable you to eliminate the wiring.
Bob

[patrickhowell]

It proved to be a wiring mix-up problem, now fixed, thanks for all your input.

[mogbob]

Well done Patrick .
Onto the next issue ... Classic cars are designed to keep you on your toes and give you a challenge. Enjoy.
Bob