How does the fuel reserve function on my 2002 v max? Does the switch stay in the on pos. meaning fuel is on or does this mean I have the reserve on?

You are riding on almost empty gas tank, or reserve. This is dangerous and fuel pumps can be inside the tank also, those need to stay submerged when possible. It is also making clogged fuel intakes that have filters more likely.

The P0670 means "Glow Plug Module Control Circuit"
The P0195 means "Engine Oil Temperature Sensor"
The P0184 means "Fuel Temperature Sensor A Circuit Internittent
The P0383 means "Reserved by SAE J2012
The P0579 means "Cruise Control Multi-Function Input "A" Circuit Range/Performance
Hope that can help you!
____________________
AK500 key programmer

Those are your PRImary and REServe tanks, although it's actually just two valve openings at different levels in the same fuel tank.

The idea is to use the primary tank all the time and if the fuel level falls below the primary inlet the bike will stop as a warning that you're running out of gas. You can then use the reserve setting to get to a gas station.

G'day
This may not help or you have probably already looked at this.
Some times they put a manual fuel switch under the drivers seat to swap from main tank to reserve it might pay to have a look.
good luck
Shayne

If its set up like mine, there is no "reserve" tank as I used to know it (I.E. a petcock that you turned to access the remaining fuel in the tank). If you mean how much is left after the fuel light comes on, I have noticed two things. The fuel light will start dim and grow brighter as you continue getting closer to empty (easier to see at night : )). I have noticed that when the light is on fully and I pull in to fuel (done this multiple times espec. when I first got the bike), I only was adding 3-3.5 gal. in fuel which means there is between 1-1.5 gal LEFT in the tank. quite a reserve off a 4.5 gal. tank, right? HaHa. Hope this helps. I generally the purpose of the fuel light and when it comes on I take note of the odometer, and pull in when convinient (20-30 miles AFTER the lite comes on and never had a problem. Probably could push it more than that, but...

Typically there are three positions to choose from. On means you are using the main tank. Reserve means reserve tank and off means no fuel available from either tank. the off setting is used when trailering your bike.

Modern bike have a two stage fuel level indicator. Flashing then solid yellow. Usually you have 5 to 10 miles when you see a flashing yellow light and about 1 mile or less when the light goes solid. Older bike had a shut-off valve and a reserve switch. You turn the switch to reserve once you bike starts to sputter or stall.

If the fuel light stay lit even after you fuel up then the sensor need replacing. That sensor in inside the gas tank.

pos lead is used to measure ground...that means that the power goes through the fuel level sending unit and the ground lowers the power out from the unit....I would replace the fuel level sending unit.

by fuel tap i take it you mean to select between the reserve tank, and to switch the fuel off... on from 'new shape' models (2006 onwards) there is no switch: it has a vaccum system which sucks any unused fuel back into the tank..

when the fuel light comes on the 'reserve tank' is in use, so go fill up with some juice!