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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

Reply to
Dmitry K.
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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?

Reply to
Bonnet Lock

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.

Reply to
Myron Samila

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

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for stepby step instructions to repair the trigger to unlock the doors. The onlyother alternative is to buy a whole new unit for about $300 each.

John

Reply to
jcm

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