2000 V70 SE 285K miles - Denso, B5244S NA intake VVT, AW-5

Awoke one recent morning to a dead V70 battery and after recharging and troubleshooting, heard the central locking system repeatedly clicking. First I thought it might be the glovebox light, but the continual cycling of central locking is the likely reason the battery discharged overnight.

Pulled #6 Central Locking fuse and the clicking stopped. Installed new 20A fuse. Now, the clicking comes and goes intermittently, and I wait until it stops or pull the #6 fuse before leaving the car. Haven't yet figured out where the clicking originates (doors, tailgate, relay?). Three of four door lock modules have been replaced over the years. Tailgate latch has not been replaced.

Anyone had this or similar issue?

Update:

Spent some time inside of the car and attempting to isolate the clicking noise (i.e., with all fuses in place, ignition off, windows down, cycling all door and tailgate locks, cycling through electronic driver seat adjustments). Finally, the random clicking was isolated to the driver seat adjustment controls.

I did a visual check of the under-seat wiring and routing, ensured wire harness plug was seated (it seemed a bit loose) and detached/reattached the switch console located on lower driver seat. Seat controls had been intermittent and in hindsight, linked to the intermittent clicking noise.

With the above troubleshooting, the clicking noised has stopped and seat controls consistently work OK. Will monitor for any repeat symptoms or recurrence.

The previous pulling of #6 central locking fuse to stop the click was likely coincidence, as there now appears no connection between seat control and central locking circuits.

While on the subject, I'm guessing there is an electronic seat control relay somewhere. Anyone know the location of that relay? (I did not remove the driver seat when performing the above troubleshooting). The relay is what I would have checked next.

Thanks,
Robert

Most likely, the relay is up under the dash, driver's side. More than likely a seat plug became loose and caused a short, sending electrons all over the place!

The location of the seat plugs can be prone to heels while the cruise control is active...

--
Keeping it running is better than buying new

Hi Robert,

That's a funky problem.
Why did you change Fuse-6 ?
Do all of the door lock buttons cycle up and down when it malfunctions?

Looking at the 850 scheme:
I'd pull fuse 32 which is for the remote control module /central lock/alarm.
See if it's the same fuse in your V70, and pull it to disable the remote.
The problem might be a fault with the module, or some unwanted RF nearby.
Is a toddler or ex-wife playing with your key fob?

Post back with your findings.

Good luck, Bill

Thanks for the reply Bill.

Attached photo shows the auxiliary fuse panel for our 2000 V70 SE.

"Why did you change Fuse-6 ?"
- Pulling #6 fuse disabled central locking, including fuel door. When #6 fuse reinstalled, the clicking stopped for a while and all doors, tailgate, fuel door worked normally. But later, the clicking starts again.

"Do all of the door lock buttons cycle up and down when it malfunctions?"
- No button cycling. Only an internal clicking as if the lock is partially cycling and doesn't know when to stop, although there is no button movement.

"I'd pull fuse 32 which is for the remote control module /central lock/alarm.
See if it's the same fuse in your V70, and pull it to disable the remote."
- See fuse #10 on the V70 SE panel: (Remote Keyless Entry). I'll try pulling #10 and see what happens.

"The problem might be a fault with the module, or some unwanted RF nearby.
- Is a toddler or ex-wife playing with your key fob?"
The key fob batteries might be weakening, but the fob still works to unlock the doors. No one else has access to the key fobs.

Will pull #10 and report back.