Flat Battery

[wobblyweb]

Can any advise how to check if there is a drain on the battery when everything is switched off. the battery flatens after one week,I have tried a new one and the same happens. i did have a problem with a headlight solenoid and now it always feels warm. I would like to connect a voltage meter, check out what is happening then remove the solenoid and see if there is a difference.

Thanks
Rae

[types26/36]

Rae,
You really need an ampmeter to check for current draw, but failing that you could disconnect one side of the battery and in the dark touch the battery terminal to the battery post, you might be able to see a small spark. The problem here is if you have a clock/imobilzer/radio(with memory) / or any other divice drawing a small current you will proberbly see a spark. A clock should not flatten the battery but an interior light would, dont know what car it is but if its got an auxiliary position on the ign switch dont leave it in that position.....just turn to off.
rgds Brian

[gjz30075]

You can pull one of the two fuses to help determine which part of the circuit you need to deal with. Pull one of the fuses, let the car sit a week and try again. If the battery remained up, at least it narrows down the options. If the battery is dead, then you know its the other half of circuit, the one handled by the other fuse. To absolutely nail it down, charge the battery again and pull that fuse and let it sit a week.

Greg Z.

[nebogipfel]

Another favourite on cars over the years has been glovebox or boot lights staying on when closed

[BillGavin]

That warm relay worries me. If you have the "switched" and "always hot" power leads in each other's position, the headlights will work, but you'll have a warm relay, an overstressed headlight switch, and, probably, a flat battery.

- Bill

[1964 S1]

I go with Bill, warm relay equals problem (no matter what) that needs attention. Interior hidden lamps as mentioned are also easy fix suspects. Finally, as odd as it seems, some new batteries are defective. Good Luck, please let us know about the fix. Eric

[wobblyweb]

Thanks for the help, I have had the relay off so maybe have connected it the wrong way.
I will just disconnect, recharge the battery and leave for awhile to see what happens.
Brian, can I connect a multi meter over the contacts of the battery and read a negative if the relay is pulling current? What about using a ampmeter guage over the batter, will that pick up a discharge.I would like to check out what happens when I disconnect the relay to pinn down the fault
The car is an Elan Sprint.

Thanks
Rae

[types26/36]

Rae,
I am not an electrician so any one more qualified please step in.
If you are talking about putting a voltmeter across the battery and checking for a discharge its unlikley to show any significent reading unless you had a major short,
you would see a big spark when you connected/disconnected the battery.
A fully charged battery with a 40 amp hour rating would (in theory) be compleatly discharged in 40 hours with a 1 amp draw, the car would not start long before this when it got to 9 -10 volts (I forget the formula volts/amps etc)
To give you an idea about current draw my Sprint pulls about 0.25amps with the dashboard light on (door open) but not with the two interior lights on (fhc)
With the ign on it pulls about 2.8 -3.0 amps (Luminition)
You need a multimeter (preferable digital) with a low scale, disconnect one side of the battery and connect the multimeter (set to amps) to the battery post and to the battery terminal DONT START CAR or you could damage meter!
Connect/disconnect the relay and check readings, a relay will operate with a small current and if its getting warm with every thing off its getting current from somewhere, it could be a faulty relay or it is being fed from somewhere else.
Brian.

[wobblyweb]

Hi,
It is the headlight dip solenoid. I have had it disconnected so I am not sure now if it is faulty or wired wrongly.

It has 4 wires and the manual dosnt show where they should connect to.
They are thin Red/ Black, thin Blue/ Brown, Thick Blue/Red and thick Blue.

Any help with the correct connections greatly appreciated!!

Rae