most likely a faulty relay
there is a bit of rubish caught in the heater fan.
Completely normal. Chances are it only ticks when hot water is running, that is because it needs to work to keep heating the water.
A ticking or clicking sound is probably lifter noise, the valves need adjusting
Not enough power to starter motor.
Could be the Climate Control Unit or Clogged heater core.
http://www.markviii.org/LOD2/blend_door_repair.htm
Yes, as a child I heard them for years at my Mum & Dad's house. It's a very gentle tick-tock for about 20 seconds then pause for about 15 seconds before starting again. I have a different sound in my kitchen - which I can only describe as a fairy snoring. A regular, soft buzzing sound which, like the 'ticking' spiders can be disrupted by hitting the table or wall near to the sound - and I hear it in different parts of my kitchen on different days. Now, clearing mum and Dad's house - in the silence, the ticking spiders are still there, just like they used to be.
The only thing I can think of that would make a sound on a regular BMX would be the ticking from the pawls in the freewheel/freehub mechanism - the one way clutch that allows you to keep the pedals still while rolling forward.
Check the ac compressor and clutch to see where the noise is coming from. Also check the compressor drive belt for wear.
An automobile's heater that blows only cold air could either be a faulty thermostat or, more likely, a faulty heater core. A trip to a mechanic or shop that specializes in radiator and cooling system repair should be able to diagnose and repair any problems.
If the car is ticking but not turning over when trying to start, it sounds as if it's an electrical issue. The ticking sound is probably the starter solenoid. It sounds like there's not enough current to engage the starter. (They require quite a bit of juice.) I'd suggest checking the battery, alternator, and battery cables.
The (DCCV) dual climate control valve may be damaged also called heater control valve.