New battery flat - suspect ignition switch?...... Thoughts please folks

[BartonStag]

Hi all,
Firstly can i just clarify i've just moved house - am still in a mess so haven't actually checked anything! Just looking for any initial thoughts please good folk of the forum. My ignition switch was shot, so ages back bought one from ebay supposedly for a Stag. Fitted it not so long back now along with a brand new battery. When i went to pull the shear bolts up the barrel wouldn't pull right up to the column, on investigation the barrel casting where it fits up to the column was different. My car is a mk1 and the faces concerned were m/ced to 90 degrees, whereas the replacement had a small though significant radius cast into it. I removed the metal and fitted the switch ok. The battery however was dead as a dodo two days later with the car not having moved. The vehicle is in a basic state ie no radio fitted to give a small drain, all lights definately off so wondered if the switch may not be the correct one? The back of it where it meets the actual ignition switch is different in appearance though outwardly everything appears to do the job. Could it be a similar switch but not actually fit for purpose, such as one from a Stag mk2 (or are they the same) or maybe a Triumph 2000/2500 etc.
Not sure quite where to start with this one so any assistance would be appreciated. Also if the ignition switch is of an incorrect type does anyone have a good spare unit to sell please?

Thanks
Gord

[andy p]

time to get a multi meter on the battery to see if there is a drain to start with

[Robmsharp]

I agree but remember such things as the clock will show a small current drain. Another clue would be as you remove one of the battery terminals you might see a spark indicating a high current drain.

[Stagsongas]

Gord,

Recharge the battery, switch off as normal, leave a few hours and see if the coil is hot. If it is hot, the ign. switch is at fault.

It may also be worth checking the alternator which has the potential to discharge a battery through earth leakage.

Good Luck

Steve

[BartonStag]

Certainly have a few places to start checking then! Thanks to all for the replies so far - anyone have any idea about the actual ignition barrel?
Cheers
Gord

[Mike Stevens]

I'm pretty sure the switch assembly is the same as a big saloon type, but it is possible that the wiring is slightly different. It certainly is different for the light stalk switch, but that's all about dip/main headlights.

Use a multmeter (with care!) in series with the battery -ve lead to body to measure the leakage to earth. Start with the highest current range on the meter and then work down. I would not expect more than a few mA or perhaps 10s of mA. If your battery went flat in 2 days (and it was fully charged beforehand) that would imply a current drain of > 1A.

Please be careful when measuring current. There is an awful lot of energy in a lead-acid battery!

Cheers,
Mike.

[Andrew S]

Check boot light first. See if bulb is hot when you open the bootlid. If so, the swithc is missing the striking position. A multimter is a good start as suggested. You could also then remove a fuse one by one and see if it holds a charge, you will know something in that circuit is the causing the drain.

[Mike Stevens]

...or remove one fuse at a time while measuring the leaking current and see if it changes!

Boot light is a good point. 6W bulb I think, so ~0.5 amps. Approaching 2-3 days to flatten the battery.

Cheers,
Mike.

[BartonStag]

Thanks for the guidance folks it's all being taken on board. Please keep it coming.
Cheers
Gord