Voltmeter Power Source Question

[tgreese]

My take - anything with mechanical contacts (fuses) or moving parts (circuit breakers) is less reliable than what is essentially a piece of wire (this is a fact - not opinion). Probably costs less too. The fusible link is supposed to last the life of the vehicle, and there's negligible danger it will accidentally go open. A fuse or circuit breaker implies that it might "routinely" be needed. If you blow the fusible link, you have a big problem that might otherwise cause a car fire.

[memsiej]

Makes sense. Good- I'll leave them as fusible links.

Just tried to fire it up- the voltmeter didn't work. I tried the direct power (the red wire going to the battery) and moved the ground. Switched the +/- in case I'd mixed that up. Still nothing.
When I took it back apart I realized the needle was trapped, and maybe that's why there was no movement. After fixing that and trying again, now the voltmeter and oil pressure gauge don't work. But all continuity on the board is a-ok.

Shoot.

[tgreese]

Did the other gauges work? Oil pressure gauge and voltmeter are on the same side of the board; that might be a clue. Do you have a multimeter? Test your connections, including the ground.

Be careful with applying voltage to the gauges. They get regulated power from the green trace shown on my picture. Power from 14 to 15, where its regulated down by the temperature gauge to about 5V, coming out A3 and going to the other gauges. You can take the whole panel out and test with clip leads and a battery.

[memsiej]

Other gauges worked. Everything on the board, green part included, test OK for continuity. All connections are tight. Was I wrong to run a ground off the negative post on the voltmeter? Does it only need power to one post?

Trying to find a video to demonstrate how to bench test the volts, as I'm much more of a visual learner.

[tgreese]

Can't help there. I'd much rather read than have someone yak at me. I don't want to spend 30 minutes listening to something I can read in 10.

One to positive, one to negative. Connecting backwards probably won't hurt it. Should be labeled though. Figure it out.

[memsiej]

Yea, I've noticed we're different in that way. You learn by reading, I learn by seeing/doing. Being a 3rd grade teacher I pick up on different learning styles

I tried using my 12v portable battery jumper- one clip to each post. No needle movement, and the jumper just beeped at me. I guess it's not that simple. When I get home I'll test the wires feeding power to the gauges (though if all the others are working I suspect those are fine).

[letank]

When I took it back apart I realized the needle was trapped, and maybe that's why there was no movement.

I had this stuck needle happened as well, on hot days, after a few run... I shaved the offending spot.

VoltMeterBindingBro.jpg

VoltmeterBindingClearBro.jpg

[memsiej]

I noticed that and wondered if that might have been a problem. I considered shaving off part of that cylinder on the oil gauge, but didn't know if there would be negative impact or not. Good to know it's doable.

I just have to figure out why now the oil pressure isn't working all the sudden.