SRS light is on, and the seat connectors look fine!

Most F and TF airbag modules can be well over 20 years old, over this time they lose their prime pressure which either makes them fire weakly or just not fire at all wnen in a collision.
If you buy a second hand one, you can end up in the same situation with a 20 year old unit.
If I was you I would disconnect the plugs under the seats and put resistors in the sockets.and unplug it from the coupler.

My 02 TF 13 spares car had extensive front end damage, the airbag did employ but was too weak to split the plastic on the steering wheel, it just made a white mess round the stalks,,, it was just worn out due to age.

I've not found anyone who recharges air bags, they might exist.
As for new genuine spares, these must be new old stock, spares are not made anymore except for after market spares, when were they manufactured? the last tf to leave the factory was 2011, so the manufacture of spares must have stopped then as well, so if it's original, it's still a 12 year old part
Like anything else they do degrade over time.
If you buy an airbag unit, it just might be totally fine, but the only test to find out if it works is when you have a bump.
I've bought spares from many places, but as yet not found any Fs or TFs with the airbags that's been fully deployed.
MMMmmm food for thought.
I've completely disconnected my bags, but I do have 4 way harnesses fitted.
Cheers Ray

JoCoLo said:

They are not gas, it is an explosive that detonates and makes gas very very quickly. My Avensis is having a new bag fitted next week. It is 18 years old but Toyota are still recalling the airbags. Fitting is free.
I think with time the explosive becomes less and less effective and due to the atmosphere around it weakens.

Click to expand...

I agree, with the Fs and TFs being open tops, how many times has the steering wheel been soaked, water and dampness get everywhere.
Maybe there is a way to change the charge, but I wouldnt like to attempt the repair.

JoCoLo said:

That means the MOT for airbags in cars our age is totally pointless. I have suspected this was the case for a while now as airbags had a sell by date on them. Best not to rely on them going off I suppose.

Click to expand...

It looks as though the MOT rules on warning lights confuse the Mot testers, it seems like if your car is older than 1st July 2003 it doesnt matter if the lights are on or not, they cant fail the car.
But what is the meaning of RELETIVE lights?

The MOT failure rules on warning lights state: (taken from the Government website)

You need to inspect MIL and relative warning lights fitted to:

• petrol vehicles including hybrids with 4 or more wheels, not more than 8 passenger seats in addition to the driver’s seat and first used on or after 1 July 2003 Cheers Ray