Best way to test gauges???

[4spdragtop]

I have quite a few gauges and was wondering how to test them?? I know there was a thread on here somewhere that said use a 6v battery. Can I test them out of the cluster, or should they be tested in the circuit board?? Im going to sell some of them and would like to verify their condition before I do that.

Thanks
4spdragtop

 

[Gryzynx]

For the purposes of testing a gauge, a 6V battery will work fine. If you need to verify accuracy, it's a little more complicated.

If you just want to veryify that it works, connect it across a 6V lantern battery. You don't need something that will supply lots of current. Make sure the gauge operates smoothly thru the full sweep. Don't leave the gauge connected longer than you have to, but it will survive a few minutes of this with no problems. You may notice that the gauge reacts somewhat slowly compared to how it operates in the car. This is normal and I'd be happy to discuss why in PM's if you wish.

 

[67Dart273]

This is normal and I'd be happy to discuss why in PM's if you wish.

You really should just go ahead and post info right here in public. The rest of us just might learn something.

 

[4spdragtop]

Pm coming your way gryzynx, but if you want post the info here. Maybe this should be a sticky...Im surprised there is no stickys for elec....seeing as how it confuses me soooo much!!

 

[skykeith]

The gauges operate faster in the car, because the instrument voltage regulator puts out full battery voltage that's "chopped up" (or pulse width modulated) until it resembles about 5 volts. The voltage spikes, which the test battery doesn't have cause the gauges to respond a little faster.

 

[Gryzynx]

The gauges operate faster in the car, because the instrument voltage regulator puts out full battery voltage that's "chopped up" (or pulse width modulated) until it resembles about 5 volts. The voltage spikes, which the test battery doesn't have cause the gauges to respond a little faster.

Couldn't have said it better

You really should just go ahead and post info right here in public. The rest of us just might learn something.

Well, I really don't want to get into one of those dick measuring contests.

You and several others here are very knowledgeable, but the argument that follows is making everyone's eyes glaze over. OP wants a simple way to test gauges, I'm trying to help.

 

[4spdragtop]

Couldn't have said it better



Well, I really don't want to get into one of those dick measuring contests.

You and several others here are very knowledgeable, but the argument that follows is making everyone's eyes glaze over. OP wants a simple way to test gauges, I'm trying to help.

Thanks Ray, got yer pm, now to get the bench and pipe setup!!LOL Probably got about 20 or so gauges to chk.

Thanks!!

 

[cudajim]

If I were testing gauges I'd limit the current using a resistor less than 50 ohms (or less) so you don't burn out the coil on the gauge.

 

[67Dart273]

Well, I really don't want to get into one of those dick measuring contests. .

That comment, you just did.

If someone could come up with the various gauge sender resistances "from the old days" as I know they had test instruments at the dealerships, it would be easy. The resistance for fuel is around, but I don't have it at the moment.

But having sender values for temp and oil would be helpful. It just is not that difficult to rig up a temporary power supply to check them.

By the way there are lots of aftermarket gauges that aren't much more accurate.

"All mechanical, all the time" used to be my motto. Had a SW fuel gauge with SW sender in my old FJ-40 Landcruiser. Never did get it very accurate, and you could yank the sender right out the top. Finally settled for "MT" The rest was a guess.

 

[krazykuda]

Miller tools used to have a special tool/gage for this. I'm not sure if it is still available. I believe that is is much safer to use without damaging your gages. I believe that it could test max, half, and min. I used to have two of them, but lost them in a move.

If you look in an old service manual 68,69 etc, it should list the tool number and you can call Miller tools and ask if it is still available.

 

[67Dart273]

Miller tools used to have a special tool/gage for this..

That is what I was thinking of. So far as I know, all it was was switchable resistors in a box to replace the sender. If someone could find out what those resistor values are, you could easily just buy 'em.

 

[4spdragtop]

I have been testing with a 6v battery for a short spurt. I havent tested all of them, but for some I have, seems to work great! Cant remember which one, but you have to do it differently(havent done it yet)

67dart273 as you can see with lots of threads, ya can get into a pissing match. Gryzynx helped me out, and if you pm him I am sure he will help you too, or start another thread asking the same question. Gryzynx never told me not to post his info, but I respect his reply here and wont post it unless he gives me the ok.