Quote:

Ok, I found the article referenced. It looks to me like the 270ohm resistor is supposed to go from the output to ground. What that will do is supply a small load (18mA) to the regulator to ensure that it outputs 5v. With no (or little) load regulators aren't guaranteed to output their rated voltage, like you noticed.

Ideally the regulator would have capacitors (10uF to 100uF, or bigger) on both the input and output. This also helps the regulator work better.

http://www.moparts.org/Tech/Archive/elec/11.html

For capacitors, the long lead is positive. They should also be marked with a vertical strip to indicate the negative pin.

edit: I would also highly recommend heatsinking the regulator, either to the can, or a seperate heatsink. With all three gauges pegged, they will be drawing just over the rated current, which will make it get HOT, and cause the output voltage to turn off or otherwise act weird while it cools.

-Dave



Hoozie, I can't read those "picchhers" very well but it APPEARS they are hooking that reistor from the negative lead to ground, and the TAB is already grounded, meaning the same place as the neg. lead!!!!! In other words that resistor is hooked to ground on both ends!!!