2008 Nissan titan would not when key is turned

Titan talk is a great forum:
ac heater vent clicking noise Nissan Titan Forum

and a vid

If you are taking on such a huge job as a head gasket on a Titan, why oh why didn't you MARK EVERYTHING.

Titans have had an issue with a relay in the IPDM(fuse block), when I was at Nissan we replaced about 3-4 a week for the same problem.

You had leaking hoses replaced & now you
have other issues?

Some shop you went to

Sounds like it is low on fluid or the
pump is whining

When you can't take the noise anymore,
replace the pump

Have to use the correct fluid,maybe that
wasn't done as well

The Steering Rack may have failed from no
fluid changes every 3 years & that is your
restriction,not the hoses,rack may be bound

check battery voltage! the noise is most likely a relay with not enough voltage to keep coil energized.

There is an actuator that moves the diverter that makes the noise.

See this thread for a how-to fix.

http://www.titantalk.com/forums/titan-problems-dealer-service/105851-how-fix-annoying-clicking-heater-ac-actuator-under-dash-w-pics.html

As for the beeping noise, could be the tire pressure sensor. When it beeps, look for a yellow warning light that looks like this ( ! ) Means you have a tire that is low on air.

Sounds like an axle joint possibly

nissan is a piece of **** **** u and your truck

Cleaned battery terminals? Checked to make sure you have full 12v at the battery? Find the click noise and make sure if it's a relay, that power is getting through it to the starter, if not check the starter out.

If the wheels are turned to one side, try turning the steering wheel in the direction they are pointing, taking tension off the lock. likely you will be able to turn key then.