2004 montana tach wire

The voltage is actually a pulsating DC voltage.   This makes it hard to read for some meters.  But those meters will usually pick it up as a DC voltage.

Thanks very much everyone. It was the correct wire. The unit is working now! I just need to connect the door locks and I can consider it done! There is keyless entry already, but doesn't have an alarm. Blue and white wires should do it.

Oh brother. Right when it was supposed to get easy! I can't find these wires. Well I see a bunch of wires taped up. Looks like some go from maybe the door rubber 'boot' that you see when the door is open, and down under the carpet towards the back seats. These ones? I pulled the plastic off beside the door in order to see the hole where these wires head up and out towards the door 'boot'

Now I have another question: I thought I needed extra relays to trigger the door locks. But then I read this in the door lock part of this website: "3 Wire Positive Door Locks This is one of the most common type of door lock switch configurations found in most vehicles. In most cases you will not need to add relays for this type. Most of the newer alarms and keyless entries on the market today have both positive and negative 200 ma door lock outputs that are usually capable of activating the factory relays." My starter has a 500mA output for the locks. Is this enough? Maybe I don't need those relays I have connected and ready for when I figure out where the wires are!