I've seen where the stop solenoid only has power when you turn the key on,
as soon as I hit the starter the solenoid had no juice,.. even after letting off the starter.
I replaced the switch and fixed it.
The MK2s had a blade on the pump, so you can just plug the wire onto it.
On the MK1s the wire is bolted on.
All my Rabbits have the blade upgrade,.. usually a blade from an old headlight ground down a little where the connector slides on because headlights use a wider connector.
This way you can carry a wire with a plug and clip it directly to the battery, if it fails to start again.