Dear greenvolvo,

Hope you're well. Power to the driver's seat motors is controlled by a computer attached to the underside of the seat. Inside the computer, there are relays, which govern the flow of power to the seat motors.

It seems to me as if the relay, that controls power flow to the "front-back" motor is "on the way out". The relays are not available as a repair part. However, you might find a "commercially-available" substitute relay.

It is not likely that the seat motor has failed. I can't recall a report of such a failure in more than a decade of reading BB posts.

A salvage yard may be able to supply a replacement seat computer. The Volvo part number is: #9128546; it is about $300 from a US-based Volvo dealer.

Before spending anything on a replacement computer, I'd inspect the drive cable to make sure that it has not worn so much at one end, that it slips. See the site's FAQs for how to inspect and to upgrade seat drive cables.

Before removing the seat from the car, write-down the radio security code and then disconnect the battery's negative cable clamp from the negative battery terminal. Put the cable clamp in a plastic bag to isolate it.

Wait at least 20 minutes. This de-energizes the SRS system, and so ensures that the SRS module (beneath the carpet, below the driver's seat) cannot trigger an airbag deployment, should the seat slip from your grasp and land on the SRS module. An airbag deployment can be lethal at close range.

Hope this helps.

Yours faithfully,

Spook