Good evening all!

I drive a 2008 S40, 2.0D, 136ps. I've had this car for 3 years and there has been the odd electrical glitch, like the steering lock not unlocking, or the dash cluster dying, or the abs service light appearing or the CD player not working. But these things have happened once, and never again. Just random electrical faults. I have never found the cause for these problems as Volvo need the fault to appear when testing.

My headlight bulbs also pop quite regularly which I am assuming is an electrical fault. And the radio has recently stopped working when connected to any channel apart from the Bluetooth receiver in my car.

Anyway... over the last 2 weeks, my car has started every time, but has been a little lumpy.

Today, after 3 days of being stationary, the car didn't start, it just clicked. It had battery power, but just clicked. I rolled it down a nearby hill to bump start it, and that did not work. After 3 attempts, I gave up, and used another car with jump leads attached, and it got the car started. Although the alarm service light was on, and the power steering was heavy at times.

When I arrived home, I checked for parasitic drain and there is 1.46 amps of drain. The fuse for the ECM accounts for 1.00 amp of the drain, the other 0.46 I haven't found yet.

I really like the car and would like to keep it a while, any help is appreciated!

 

It can take up to a couple of minutes for control units to turn off. Open a door, 3 control units turn on, turn the light switch 2 more, say a few curse words, 3 more control units turn on. - So that makes it very difficult to check for a parasitic drain, you have to wait for them to turn off, every time you check something. Hopefully you are using a non-contact ammeter.

How old is your battery? More than 3 years? Replace it and see what happens.

 

Thank you, the battery is less than 12 months old, I changed the last one after this happened to see, but something on the car is draining the battery. I just don't know what 😐

 

I have replaced many one year old batteries under warrantee to fix the "battery goes dead" problem. I sold the Interstate brand - yes a name brand but there were still some duds.

Lets see - you had this problem a year ago, you changed the battery, the problem went away, and now the problem is back. What could be the problem? What brand of battery did you purchase? Interstate has a 18? month free replacement warranty - no questions asked.

 

If you draw over 1 amp them you have an issue it will cetainly drain any battery in 3 days , the only thing that should drain is the alarm (if you have one ) but its nothing like 0.1 amps so if you are checking properly for amps (as mentioned) then you have an issue , I see you have a modification to the sound system Bluetooth ? who did that its not easy on this vehicle, but would certainly not draw much power .
To make things worse your is a diesel so needs lots more power to start
I would start with any extra that was done

 

The best way to check for parasitic drain is to use a clamp-on DC ammeter (multimeter). Careful though, as the vast majority of clamp-on meters don't do DC current, but only AC current. People get confused because they CAN read DC amps, but only if you use the leads, which involves disconnecting the battery, and can blow the meter if anything draws more than (usually) 10 amps (which can be almost anything).

Clip the meter on around the positive cables, and see what kind of current is flowing. Since having the hood up on some cars leaves an underhood light on (or possibly doesn't allow the security system to reset) I'd recommend getting a meter that allows remote monitoring via your phone. The one I got has worked out VERY well for the purposes, and was really dirt cheap. I don't pretend to claim this is the best deal out there, but is just the one I decided to buy (there may be better options out there, but I'm happy with mine).


Then you just have to sit back and monitor the current drain from your phone as the computers in the car shut down one by one. You'll know soon enough if you have a parasitic drain, or something else.