In a 2001 Volvo XC70 the wrong fuse was removed for testing and the clock time was lost and an SRS (airbag) fault was set...How can this SRS fault be cleared?

You have to be very careful with the airbag system It is very dangerous.
Before attempting anything. It will be more appropriate for a mechanic or technicians to do it. But have a look at this link:
https://www.autozone.com/repairguides/GM-Bonneville-Eighty-Eight-LeSabre-1986-1999/AIR-BAG-GENERATION-1-CORPORATE-SYSTEM/General-Description/_/P-0996b43f8038fb7d

1. Have the SRS fault code retrieve
Do-it-yourself,
2. Remove the airbag fuse wait 5 minutes at least so the condenser for SRS system to goes out. (if you unplug the battery terminal you will have to reset many things)
3. Remove the steering wheel airbag and steering wheel until you find the split ring. Unplug the connector, under the dash and remove it from the steering column.
It is very complex procedure if you never play with SRS system
As far as I can tell the noise you can hear is the

need more information than that

you will have to have the SRS system reset at volvo dealer. should be around $85 for reset

Here's a quick check list for most common cost of SRS / Air bag problem.

Dirty contacts on driver and passenger seat belt buckles

Dirty contacts on seat belt connectors (under seats)

Dirty contacts on driver and passenger sides weight sensors (under seat)

Seat covers

Weight on passenger seat
(Example: grocery package trigger SRS / Air Bag light on the way home.)

I recommend you to pass an vacuum over the contacts and use CRC electronic parts cleaner to rule out connectivity problem.

I DO NOT recommend disconnecting the negative battery connector to clean the code(s).

Without the code(s) the dealer will takes "BILLABLE" time to reproduce the problem.

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Please rate my answer if it is useful to you.

Cheers,

Mustgo

tHIS LIGHT IS ON TO ALERT YOU TO THE FACT THAT A FAULT HAS OCCURED IN THE AIRBAG SYSTEM AND THE AIRBAG DIAGNOSTIC MONITOR HAS DISABLED THE SYSTEM, THE LIGHT WILL REAMAIN ON UNTIL THE FAULT IS REPAIRED, SO RIGHT NOW YOU HAVE NO SRS, THE MOST COMMON PROBLEM IS THE FOLLOWING.
When the airbag light is on it means a fault has occurred in the system and the airbag diagnostic monitor has disabled the system, the most common problem that turns the light on is a break in the connection to the steering wheel mounted airbag, this is due to a rotating ribbon contact that breaks under the steering wheel that connects the airbag to the wiring harness and the diagnostic monitor, the part is called th clock spring contact, a coiled up ribbon electrical contact that turns with the wheel

See if you can pull the airbag fuse to avoid accidental deployment of the airbags. It sounds expensive.

ether take the bulb out, or take it to someone that will reset

Most common SRS fault in XC90's is the driver side SIPS bag (side air bag) located in the side of the seat. The wire runs close to the hinge for the backrest and after working back and forth can break or short.

If you have SRS and "brake failure" it should be taken to a dealer. a shadetree mechanic will screw more up than he will fix in this case. trust me on this! you will pay a price, but will save you more $ and less headache in the longrun.

I recently purchased a 2002 S60 D5 which had this problem. I am not a Volvo expert so don't know if it could be the same fault, but it sounds identical. No lights, gauges etc, but intermittently and very briefly comes on. Having heard some silly prices for replacement dash and ECU, I had a look. I found 4 poor soldered joints on the dash circuit board (top left processor & heat sink). I cleaned them and re-soldered them, although I had continuity just after cleaning the corrosion. The dashboard has worked perfectly since (3 weeks) . If you try this make sure you disconnect the battery first or you may have the SRS airbag warning light on! (I had to have it re-set at the dealers!!)

The whole process took less than an hour. If you are not electronically savvi get one of your mates who is to have a look..