Volvo C70 Battery parasitic drain on fuse 6 central locking

Riass · Post by **Riass** » 11 Jun 2026, 13:35

Hi,

I noticed since i bought my c70 that it eats through batteries and when it is really dead, i can't open any doors so i'm basically locked out . I decided to finally investigate with a multimeter, set it on amp and putting it between negative battery post and negative terminal. It reads 120mA (door closed, waited for modules to go to sleep). When i pull fuse 6, it lowers to 10mA. So yeah i know the circuit is the culprit but i dont know what to look for now to fix it. Any ideas ?

Or should i just live with it by installing a wireless battery disconnect switch?

Riass

helenewton · Post by **helenewton** » 16 Jun 2026, 22:52

Hello, A parasitic draw of 120 mA is definitely too high for a C70 that's asleep. The fact that it drops to 10 mA when you pull Fuse 6 strongly suggests something on that circuit is staying awake.

I think the next step is to identify everything powered by Fuse 6 (check your owner's manual or wiring diagrams) and disconnect those components one at a time while monitoring the current draw.

Riass · Post by **Riass** » 23 Jun 2026, 07:08

helenewton wrote: 16 Jun 2026, 22:52 Hello, A parasitic draw of 120 mA is definitely too high for a C70 that's asleep. The fact that it drops to 10 mA when you pull Fuse 6 strongly suggests something on that circuit is staying awake.

I think the next step is to identify everything powered by Fuse 6 (check your owner's manual or wiring diagrams) and disconnect those components one at a time while monitoring the current draw.

I'll try to find the right diagram and give it a go. Thanks !

Vova585 · Post by **Vova585** » 23 Jun 2026, 08:42

https://volvodiag.com/ewd-online-eng/
Not sure it will have your year.

Credit to scot850

Vova585 · Post by **Vova585** » 23 Jun 2026, 09:16

On the other thought.. based on the 92-00MY thread, I think that your car might have VGLA module that controls central lock system. Full disclosure- I do not have any experience with this system. I just remember reading about it. Apparently vgla was utilized prior to p2 and was in charge of storing fob information and controlled the central lock system/alarm/immobilizer(? Might be wrong on this). If I remember correctly, it is located behind the dashboard or somewhere next to the steering column. There were posts on this website about it and how to program it. Just by logic, I would first opt for either voltage drop across fuse #6 vs prior parasitic draw test method. Then based on the method selected-reconnect the battery and/or reinstal fuse six.. Open all doors and hood and move the lockes into "locked" position via screwdriver mimicking closed doors, trunk and hood(if the car does not have any wires to the hood locks, skip this step). Close the car with the keyfob.. give it 10min(likely will fall asleep even faster) and measure the draw/voltage drop across #6. Next disconnect door to body wiring connectors starting with trunk-right door-left door. With each disconnect, verify if measurement dropped from 120mA to more acceptable reading. If it dropped-likely actuator is shorting somewhere and needs to be repaired/replaced. If despite disconnecting it still shows 120mA...one can try to disconnect the siren(I think it should be horn like device at the center of the motor compartment next to firewall). I doubt that it will be an issue, but we are already there...if that is also not getting is nowhere, you can take thermal canera and look at vgla module and see if it is "glowing"(or simply warm to touch), you have your suspect and now it will be search for a used unit and some guru with knowledge if/how it needs to be programmed. Sorry, that's the best I can do

Post by **abscate** » 23 Jun 2026, 23:05

Calculations

120 mA times 24 hours is 2.6 Amp hours per day, or 18 Amp hours per week. That’s about 20% of your battery charge. A bit high but shouldn’t be killing batteries on a daily driver

Riass · Post by **Riass** » 25 Jun 2026, 08:51

Vova585 wrote: 23 Jun 2026, 09:16 On the other thought.. based on the 92-00MY thread, I think that your car might have VGLA module that controls central lock system. Full disclosure- I do not have any experience with this system. I just remember reading about it. Apparently vgla was utilized prior to p2 and was in charge of storing fob information and controlled the central lock system/alarm/immobilizer(? Might be wrong on this). If I remember correctly, it is located behind the dashboard or somewhere next to the steering column. There were posts on this website about it and how to program it. Just by logic, I would first opt for either voltage drop across fuse #6 vs prior parasitic draw test method. Then based on the method selected-reconnect the battery and/or reinstal fuse six.. Open all doors and hood and move the lockes into "locked" position via screwdriver mimicking closed doors, trunk and hood(if the car does not have any wires to the hood locks, skip this step). Close the car with the keyfob.. give it 10min(likely will fall asleep even faster) and measure the draw/voltage drop across #6. Next disconnect door to body wiring connectors starting with trunk-right door-left door. With each disconnect, verify if measurement dropped from 120mA to more acceptable reading. If it dropped-likely actuator is shorting somewhere and needs to be repaired/replaced. If despite disconnecting it still shows 120mA...one can try to disconnect the siren(I think it should be horn like device at the center of the motor compartment next to firewall). I doubt that it will be an issue, but we are already there...if that is also not getting is nowhere, you can take thermal canera and look at vgla module and see if it is "glowing"(or simply warm to touch), you have your suspect and now it will be search for a used unit and some guru with knowledge if/how it needs to be programmed. Sorry, that's the best I can do

Thanks, i'll try to locate the module first to confirm i indeed have it, i'll try what you said probably during july (finally holidays

). Thanks for the diagram too !

Riass · Post by **Riass** » 25 Jun 2026, 09:01

abscate wrote: 23 Jun 2026, 23:05 Calculations

120 mA times 24 hours is 2.6 Amp hours per day, or 18 Amp hours per week. That’s about 20% of your battery charge. A bit high but shouldn’t be killing batteries on a daily driver

Yeah, it's not much but i kind of have PTSD of the battery dying in this car. 2 years ago, i forgot headlights after parking while on my way to work, car was dead, but unlike any other car i've owned, the door locks were unoperable, couldn't open the car to pop the hood and jump start. Rear seats can't fold so no way to get in the car. Ended up shredding my arm to reach the hood lock from under the car at 9pm in winter weather...

So when i felt the car a bit weak (after not driving for 10 days) to start the day i posted this thread, i finally decided to investigate.

I guess if i can't fix it, i'll just make sure to drive regularly and disconnect the battery if i'm not using it for a while.

Post by **abscate** » 25 Jun 2026, 09:19

You cannot open the car driver door with a key??

Riass · Post by **Riass** » 29 Jun 2026, 05:53

abscate wrote: 25 Jun 2026, 09:19 You cannot open the car driver door with a key??

Yes, i have no idea why. If it dies completely, i'm locked out... So now i basically fitted a metal wire to have an emergency hood opener under the car. If anyone know why i have this issue, i'd love to know the fix !