Two electronics problems in S70: voltage drop and doors central lock

Hey people,

I've found two problems in my Volvo S70:

1) The voltage drops, so when you ride in the night with your head
lights on you can see them fade rapidly then getting lighter, the
nfade again, etc. It looks like the battery has been replaced.

2) Central locks wouldn't work in three doors: it would be able to
lock each of them but wouldn't be able to unlock. I was told it's very
likely to be the solenoids in the doors.

Has anybody faced with the above problems? If so, I would really
appreciate any type of advice/hints/tips on that (what could cause it,
how much woud it cost to repair, etc.).

Thanks a lot!

Dmitry

 

In an earlier contribution to this discussion,

The two problems may be related! For the central locking to work properly,
the battery needs to be in a good state of charge. If the alternator is
playing silly b's (which could explain your lighting problem) the battery
may not be getting fully charged.

You could try charging the battery OFF the car and then seeing whether the
central locking is ok. If it is, you need to concentrate on the charging
circuit. If the central locking *still* doesn't work with a fully charged
battery, the solenoids could be at fault.

Although I suspect that the lighting problem is due to fluctuations in the
alternator output, it *could* be caused by a bad contact in the lighting
wiring - which maybe recovers a bit when you drive over a bump in the road.

Does everything else continue to work ok when the lights go dim? Does the
starter motor always turn the engine over at a good speed?

 

Don't know about the problem #1, but I definitely had a massive headache
with my V70. Rear doors and the hatch, fuel gauge and some rear lights
occasionally became disabled. After driving a few kms, all systems just
recovered by itself. May I add, that it was most annoyning when you came
back to your car after driving a few kms and the rear doors just didn't
unlock. With a screaming kid it's not very pleasant

I was finally able to take the car, 2001 yearmodel btw, to the garage
here in Berlin. And believe it or not, it was just a software that
needed to be upgraded. The fix did cost a whopping 14 cents and there
has never been a problem since. Talk about the minor fault...

--
Kytis

"Isän tärkein tehtävä on kasvattaa tyttärensä niin
ettei hän huoli paskaa jätkää miehekseen"
J.Sarasvuo

 

I would have your alternator tested and repaired asap. If the regulator were to become
failed in the shorted position, you could easily have an overvoltage situation, which at
the least blows lamps, at the worst, destroys ECUs and such.

The door lock solenoid is an easy fix, possible something is not allowing it to open
properly/close properly (need of lubricating all the points in the mechanism), or simply
replacing it.

The #1 problem is more important, a bad alternator can also ruin a battery.

 

The door lock problem is not the selonoid, it is the red thing in the lock
mechanism that breaks off when a passenger is trying to open the door while
the driver is unlocking the doors. The only door of yours that works is the
driver door. Go to http://www.volvospeed.com/Repair/v70latch1.htm for step
by step instructions to repair the trigger to unlock the doors. The only
other alternative is to buy a whole new unit for about $300 each.


John