My truck runs great, but the Temp gauge stays on cold for about 20 miles and then goes to normal. In between that time I don't get any heat. Is the Thermostat bad?

Could be. It might even be super low on coolant also.

Could be. It might even be super low on coolant also.
No, the coolant is good. The truck doesn't over heat, so figured it's the thermostat. I just looked where the ther is at on the engine and it doesn't look like an easy fix, like my old 67 mustang was.

Where else would it be? They're always on the front. If that's your original thermostat you should probably change it over for good measure.

My neighbor had a '67 fastback. My favorite year of Mustang, and the new ones look so much like it...

Yeah it's on the front of the engine, but it's kind of deep between the AC and Alt brackets. Maybe a socket extension will do the trick and yes it's the original one.

67 mustang is and will always be the best model. It's just was built better than it's predecessors and looks a hell of alot better than any of the others. Yes the 05 does look alot like it and it's the only other year that I can say looks cool.

When you say 20 minutes, how cold is it and where are you driving? What engine do you have?

If you're getting right on the highway and it's 10* outside, then yeah it'll take awhile to warm up.

It's not 20 minutes, but 20 miles, but I guess it's about the same. I live in Southern CA so the coldest it gets in my neck of the woods is 30. I have a 5.9 in my truck.

Yup, then it does sound like your thermostat has failed, in the open position.

better open than closed right.

Yeah if it was closed then you'd just cook everything.

I found a write up on the web on how to replace a thermostat. It has a few pictures to go along. The writer states that the stock Thermo on 98 Rams are 195* and it's better to replace with a 180*. Something about being better on the engine and more power?

What do you guys think?

Here's a link to the page
http://www.vr4stealth.com/ram_thermostat.htm

I dunno about noticeable power, an engine certainly runs better when it's colder, but I don't know about "seat of your pants" noticeable power...

I'm putting a 180 degree thermostat in my truck come springtime when it warms up.

Under normal conditions: The temp guage should rise to a point around 205 (assuming 195 thermostat) then fall back to 190-195 (these guages ain't NASA quality so give or take) If guage just rises to a point and stays there, the thermostat is stuck open. Also if you open radiator cap and see coolant flow right after cold engine start = stuck or failed temp thermostat.

They're designed to fail in the open position.

As far as a 180* working better, I've seen it both ways, sometimes the engine works better cooler, and other times better with the original thermostat. Since they're not 100% accurate, then that may be due to variance within the different ones.