I have bought two of those fancy digital voltmeters for my T. The first one failed instantly,Flashed on then went completely black. The second failed after a couple of moments. The first I wired into my fuse box the second I wired to the battery. I do have an alternator and 12 volt system. Is there something I can put into the circuit before the gauge that I can lesson the amperage going into the meter? This is the meter I bought> http://www.amazon.com/gp/product/B006WHQ5JA/ref=oh_aui_detailpage_o09_s00?ie=UTF 8&psc=1
Voltmeters must not be wired in series with the load like an ammeter . They are wired in parallel across the load.
Yes, I wired the hot to the positive side of the circuit and the cold to the negative side. Same way when I hooked direct to the battery.
Will, The original wiring on a T is set up for an amp gauge.
Since it sounds like both your gauges are fried and if you still want a voltage gauge you might consider getting one of the Fun Project meters. It will look like the original amp gauge but be a voltage meter and would come with instructions.
Are you sure the battery is charged? There should be no current flowing through the voltmeter circuit other than caused by the internal resistance of the meter when connected properly. Maybe both meters were bad from the get go. I would test the voltage with a VOM that you know is good, using the same procedure you used before, then go from there.
Well, Actually the wiring harness is of my son in laws making. He's an electrical engineer and really good at what he does. Its a complete 12 volt system including the starter from Mr Becker just before we lost him. I had my son in law design a harness that can carry any load I ask of it. With this said, I still run the engine and coils off the magneto. If the mag ever fails I may go with the E Timer because of all the miles I put on the car. Like I mentioned the first time I tied into the fuse box with the ground to the frame and the second right to the battery posts. My 1919 Touring is a driver, She's no trailer queen. I take very long trips with her so I like to be kept up to date on her internal working while on the road. I have a digital Amp gauge, Digital Water temp gauge, Digital Vacuum gauge. Two cig lighter and two USB Iphone charging ports inputs. Plus permanently mounted GPS and cell phone holder and a back and forward facing video recording cameras for my own protection just in case. Its just the darn volt meter that is messing me up. I think Im going to go with the Auto Meter brand. A bit more money but in the long haul it might be worth it. Im going to call Summit racing in the morning. I have a feeling its all about a cheap $13.00 gauge. Heck, Its just a voltmeter, How complicated can it be?
Will, I think that might be a good course of action.
Recently I replaced a gauge cluster on a friends CJ5 Jeep, It took three "new" clusters to find one that worked. The vendor kept sending me free replacements and didn't want the bad ones back. It seemed that the Chinese manufacturer had a bad run, and shipped the lot out anyway.
The vendor finally found a good one from a different lot, which worked!
John Regan offers a very nice analog voltmeter that fits in place of the original ammeter. It is exactly what you need Will.
Anything with digital electronics is out of place on a Model T. Perhaps that is the problem - your Model T rejected the cheesey digital meter.
It's tough to diagnose a problem with a "custom" wiring harness since there's some unknowns but I suspect an error in the wiring or the connection. Do you have a wiring diagram--For the harness and meter? I would check the diagram for the meter. It's unusual for a digital meter to be lighted AND show ZERO volts as in one of the photos unless it has a separate circuit for the lighting. Something's not right.
Ken, Both gauges went completely black. The second flashed a number a couple times but it went black with in a few moments. I talked to my son in law about this and he said possibly the meter wasn't able to handle the amperage of the alternator. He said most good meters have a electrical amperage choke mechanism inside to protect the internal components. Theses cheap ones can't handle the current. It was a $26.00 lesson.I should have know better to get sucked into something cheap to start with.
Royce, You may have a point. With theses digital meters I can see watch within a tenth of a degree of what my system is doing. Im a need to know driver. As a rule I have one eye on the road and the other on the engine. More than once the wife has asked, Why are you smiling? I tell her a good sounding driveline is like music to my ears.
I've been a mechanic all my life, 80% of all repairs I made to customers cars were because they couldn't see or hear what there cars were saying to them.
"It's unusual for a digital meter to be lighted AND show ZERO volts as in one of the photos"
Ken, methinks the gauge showing zero is the tachometer.