Why is the coolant gauge always perfectly in the center on my ‘99? Is It a dummy gauge?

[JoshT]

all good points, but I work my truck hard. It could be 100 degrees pulling 3500 pounds up a steep hill in first gear and that stupid little water temp guage sits happily in the center. I really don’t care what it reads when I’m driving it to town for work, but when I’m hauling mowers I’d like to know if I’m working it too hard. Maybe the coolant system is way overbuilt and it’s just that good at keeping it cool. I really don’t know.

I was reading somewhere about the sender, and I recall hearing something about the resistance curve having a flat line or something where the operating range is. In other words, after it reaches operating temp it keeps voltage to the guage the same during a large range of temps. Once it exceeds that it’ll boost the current. I don’t completely understand this, but if it’s true then I should be able to get a different sender that’s got a curved line. I keep imagining it like a torque curve and how they are different for semi trucks vs city buses.

For future reference, anyone here who builds a vehicle or starts a company that does, I like to see real data in real time. Don’t care if it’s a little Honda fit or an F450, I like real information. Just in case anyone here begins manufacturing vehicles. That goes for you too Ford.

1) 3500lbs in 1st gear really isn't working the engine that hard. Trans, maybe. Brakes on the way back down, definitely. Engine, not really

2) The senders in these aren't that smart. The senders in most vehicles aren't that smart. Where that trickery comes into play is the computer, particularly in vehicles where the cluster is fed by the ecu I stead of directly. I'm pretty certain that in 98 they had a fairly dumb sensor that is connected directly to the gauge.

3) You and about 4 other people out of 100 (I'm being generous) want that type of real time data. The other 95 would be scared and confused by all that data. It would lead to a huge influx of people worrying over one instant issues. That means more customer complaints and worry work over things that don't matter, aka more expense to manufacturer. Manufacturers are going to aim for the masses and increasing profit. For everyone else the aftermarket has aux gauges, scan tools, and scan gauges.