11.4v?

That battery is bajanxed... Should be around 12.7v with engine off, 12.9v after a long drive, and 13-15v with the engine running IIRC...

 

Thought so. Love this website. Thank you.

 

Rear fog always turning on is weird and is the opposite of what it should do, which may be significant.

11.4V is sh4gged though. Probably a dead cell if it drops to that straight after charging.

 

Was just about to purchase a new battery but I hate spending money so checked the voltages again.

Engine off without key in ignition = 12.4 V (healthy)
Engine off with key turned to MAR = 11.4 V (not healthy)
Engine running = 14.2 V (healthy)

Car starts fine and drives fine but I've started getting a glow plug light flashing and sometimes the rear fog light magically lights at start up. Inaddition I'm sure the right side button in the centre console under the hand brake used to light a dash warning if pressed. Now it does nothing. Is my car haunted?

Why 11.4 V with key but healthy 12.4 V without? Someone measure their voltage at MAR to confirm my battery is kaput please.

 

12.4V is in the "needs charging" range.
Ideally you want 12.6V (with 12.2V being officially flat).

There is a reasonable load at ignition on with a Diesel with the fuel pump and especially glow plugs lighting up.

 

Thank you. Couldn't be clearer. I'll buy at the weekend and post again if the "haunting" continues.

 

Ignition on voltage is 11.4V with fan running, 11.8V without fan. Measured from *** lighter socket, battery relatively new. So it does drop a fair amount just with ignition on.

 

This is the same as mine. Will your lighter reading be accurate?

 

I would say that those voltages are not too bad. I would suggest if possible give the battery a charge over night and take it to you local auto electrical specialist and ask them to load test the battery. That should provide you with a definite result one way or the other.

Don't forget at this time of the year if you are doing short journeys with lights and heater on then the battery is getting quite a hard time. If you give it a good charge before it is damaged beyond use then it will save you a few pounds.

I hope that helps.

 

I could turn the starter and measure the lowest voltage but I'm not sure what reading would be normal.
The car starts fine so normally I'd not consider changing the battery. I currently have odd warning lights, fog lamps turning on at start up and the switch 3 under the handbrake not lighting the dash. My first thought was weak battery but now I'm not sure.

 

If it is always starting fine, then I wouldn't be running out for a new battery yet.

Poor earth can do wierd things.
I had the brake lights on my 156 locking on when I indicated left. Slightly flexing the boot release lever would then unlock the brake lights...!
The nut on the earth point below the left rear light unit was loose.

 

To conclude: I finally got round to purchasing a new battery. No more glow plug warnings or rear fog turning on by itself at start up.

 

I recently had a new battery too...

Haven't had a smokey/spluttery start since... Didn't think the old one was due for a change as it was holding 12.7V no problem, but since getting the new one in I can't believe the difference...

Although I now apparently have a right sidelight failure.... Which I don't.... Car has taken 10 months to decide it doesn't like the LED sidelights :jester:

 

Ah, a happy ending at Christmas! :inlove: