Danne,
Let me start by assuming you are addressing these issues in a BJ8 either a Phase 1 or 2.
The Healey has only 2 fuses and protects very few electrical components. The larger amperage fuse covers only the Horn and the smaller protects the Directional Signal switch, Heater Fan switch, Fuel Gauge, Wiper Motor, Revolution Counter, and Stop Light switch. Additionally, a fuse. located in the boot, was installed to protect the identification plate light from shorting and burning the rear harness due to water entering the plate light. Based upon this limited number of protected car components, it is more likely that the issues you are dealing with are the result of corroded connectors although it is not out of probability that you may also have a few problem components as well.
First, your panel lights are powered from a power contact on the headlight switch and will only work when the headlight switch is on. There is no headlight fuse or panel light protection so I would suggest you check the contacts to and through your headlight switch for power and ground connection at each light.
The windshield spray is not electrical but a repetitious push to its dash-located pumping device. This pump stops working due to a common internal diaphragm failure.
Power to your heater fan switch is protected by the smaller of the 2 fuses in the fire-wall located fuse box. If your heater fan does not function, it could be a fault in the switch or fan as power passes. If this device does not function and the fuse is good, check to make sure the dash switch is functioning and clean and then check the ground and power connections to the fan. Since replacing the fan is an uncomfortable task, I would check all connections prior to resorting to the fan's removal.
Last, to address your radio failure, I would first look for an independent in-line fuse as they were usually placed as part of the radio installation. Again, corrosive connections (power and ground) are problems and especially with radio antenna attachments at both the fender and radio.
To protect my Healey from these same issues, after cleaning and/or restoring the integrity of all my electrical connections, all my bullet connectors were coated with liberal amounts of a dielectric grease. Under the pressure of connection, this grease easily separated to provide good contact and eliminates water and humidity from entering. Additionally, I chose dielectric grease over a conductive grease to take advantage of its non-conductive quality and eliminate any flash over.
Danne, enjoy your Healey and enjoy its puzzles.
Ray (64BJ8P1)