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View Full Version : Electrical or Mechanical gauges- what's the difference?



Tony J.
04-21-2004, 16:29
I'm trying to decide which type to get- what is the difference between electrical and mechanical gauges? I'm looking at Autometer... Is one more accurate? Easier to install? I'm thinking of installing mine in my overhead console where that "blank" panel is forward of the eyeball lights. Anybody done theirs this way? Is it possible?

CoachWagner
04-21-2004, 17:08
I have the autometer gauges and think they are great. I don't think you will have enough wire to reach the overhead console for the EGT and it says that you can't just splice more wire on cause it throws out calibration. There is not enough boost tubing but you could buy longer lengths of that if you want. I have mine on the pillar and it is really easy to keep an eye on.

patrick m.
04-21-2004, 17:12
electrical, or mechanical....hmmmm. This is going to be a matter of opinion, some will argue that mechanical is better because it is simpler, fewer parts to go bad, no electrical parts (stay the bulb) and cheaper.
others may argue electrical is better technology, more accurate, if not, why is everything using more and more electronics.

i got some fancy guages, and within a few months one does not illuminate, and i cant replace the bulb because there is no bulb! They use some kind of "phosphorus" coating that is fed power through a 2600ohm resistor. The really cool thing is the warranty does not cover illumination problems :(

if you are looking for opinions, here's mine: buy a very good mechanical guage set (where mechanical is availible) and make sure they use bulbs ;)

Bobbie Martin
04-22-2004, 04:29
What kind of gages are you installing? Typically boost are mechanical, you could probably find an electrical one but its pretty easy to hook up a mechanical boost. Most EGT gages use an easy to install thermocouple and a fixed length wire. Not really sure it would be considered electrical as there is no power wire but not really mechanical either. Electrical (oil, water, trans, etc.) temperature gages are much easier to install, mechanical temp gauges have a metal flexible tube that are kind of a pain. For what you are doing, I can't see accuracy of mechanical or electrical would be much different. A friend of mine uses a Cyberdyne digital temp gage. He likes it as you can see differences of a degree or two that you might not see in an analog gage. You can see the water temperature rise slightly at stop lights. Engine oil (or fuel) pressure I would go electrical, a mechanical gage requires plumbing the engine oil into the passenger compartment. Something I don't like to do for several reasons.

cruzer
04-22-2004, 06:14
Electrical gauges use sending units screwed in the engine and then you run wires to the gauges.
The gauges read the resistence from the sender, similar to a gas gauge.Sending units can go bad.
Electrical is easier to install.

Mechanical is a little harder to hook up. For instance, with water temp there is a temp probe that runs to the engine which is mabe 1' in diameter and a heavy cord that feeds the gauge. They usually can't be disconnected. It's length is it's length. There is no eletrical current going thru it. If the cord is crimped or cut it usually can't be replaced. A hole will usually you have to be drilled in the fire wall for the probe. An oil gauge has a tube(plastic or copper) going the engine, and you plumb that tube to the gauge. Oil is fed to the gauge and the gauge determines how much pressure there is. I run Autometer mechanical gauges and like and trust them more than elctrical, but that's just me. They are both fine. The main thing to me is the accuracy, so a good quality gauge is in order.

If you are going to mechanical Autometer, you will need to get a special adapter that A/M makes, so the temp probe can be installed in the head on a 6.5td. FYI