Dash Wiring

I got my dash wired up over the last couple of evenings:

The wires are all wrapped in self amalgamating tape, and held in place with cable-tie saddles screwed to the dash with self tappers.

In the middle of the dash are the mini clocks.
Just below them is my VRS-to-digital interface for the speed signal.
To the left are the hazard and fog switches, and a relay I had to add to invert the hazard signal.
To the right are my CAN interface modules to take the various signals from the car and generate CAN messages for the mini clocks.

Plugged it into the car and most things seem to work!
Need to do a small tweak to the RPM, as currently it's displying twice the engine speed!
The brake warning isn't quite working.  Turns out the brake sensor is 500 Ohms when off - hadn't expected it to be anything like that, so will need to reduce the value of my pull-up resistor for that input.
Haven't tested the speed yet, but don't expect the scaling to be anything like correct!
The only other thing I'm not sure about is the fuel level.  It's currently displaying as 1% full with about 10l of fuel in the tank, so that might need some futher investigation.

---------

UPDATE:
I spent some more time on this over the bank holiday weekend, and all the dash functions now work :)  (except possibly vehicle speed which I haven't yet checked).

Adding a 1k pull-up to 12V to the brake warning signal fixed that problem.

Tweaked the code to fix the double RPM issue.

I've left the fuel level as is for now.  It sort of works, in that it's fairly accurate at full tank and empty tank.  The problem is that my code assumes a linear voltage from empty to full, but in reality it's curved.  I might add some code to linearise the signal at some point, but it'll do for now.

Whilst testing I spotted that my indicator tell-tales weren't keeping up with the indicators, but just sending the CAN messages to the clocks more frequently fixed that.

Also noticed my charge warning light was permanently on.  That needed a 120 Ohm pull-up with a diode in series adding.  Not sure why, but it appears that alternators need quite a strong pull-up resistor on the charging light wire to actually initiate charging.