Vot Meter acting funny
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Vot Meter acting funny
- Thread starter dwickens1
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Barry2
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Do you have the neg. side of the Voltmeter grounded, as it should be and the plus side to the ignition switch?
Torxhead
Always Off-Roading Jeeper
Start with the usual suspects, like a bad ground connection and light bulbs.
Torxhead
Always Off-Roading Jeeper
O.K., I would next check voltage at the headlights to begin tracing the system down. Is this voltage drop with or without the engine on?
BusaDave9
Always Off-Roading Jeeper
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- 1979 Jeep CJ5 with 304 V8, T18 Transmission, Dana 20 Transfer case with TeraLow 3:1 gears, 4.88 axle gears, Detroit Locker up front and Ox Locker in back with 1 piece axle shafts, 36" SuperSwamper SX Tires, Shackle reversal, MileMarker Hydraulic winch, MSD 6A ignition.
Water damage? Interesting. Let's keep that in mind.
You replaced the volt meter. OEM gauge. You wired it up the same as the original OEM.
It works fine until you turn on the lights. Then it reads zero.
If you hooked it up correctly then that tells me one of 2 things:
1. When you turn on the lights the supply voltage at the key switch drops to zero. That's unlikely.
2. When you turn on the lights you are also energizing voltage on the dash.
I think the 2nd option is most likely. You may also have a bad light switch. It could be supplying voltage to the dash (which should be ground). Remove the volt meter ground wire from the dash. Instead use a long ground wire and route it all the way back to the - side of the battery. This is just a test but let me know if that fixes it. You could just hold the wire on the battery terminal as someone turns the key and turns on the lights.
EDIT: Also try rotating the light switch so the dash lights are off. The switch should apply voltage to the dash lights when you turn on the lights. It may be shorting to the dash. It may be supplying voltage to the dash instead of the dash lights.
You replaced the volt meter. OEM gauge. You wired it up the same as the original OEM.
It works fine until you turn on the lights. Then it reads zero.
If you hooked it up correctly then that tells me one of 2 things:
1. When you turn on the lights the supply voltage at the key switch drops to zero. That's unlikely.
2. When you turn on the lights you are also energizing voltage on the dash.
I think the 2nd option is most likely. You may also have a bad light switch. It could be supplying voltage to the dash (which should be ground). Remove the volt meter ground wire from the dash. Instead use a long ground wire and route it all the way back to the - side of the battery. This is just a test but let me know if that fixes it. You could just hold the wire on the battery terminal as someone turns the key and turns on the lights.
EDIT: Also try rotating the light switch so the dash lights are off. The switch should apply voltage to the dash lights when you turn on the lights. It may be shorting to the dash. It may be supplying voltage to the dash instead of the dash lights.
dwickens1
Jeeper
@Busa Dave,
Ok it was a bad ground causing the the volt meter issue and I found it through the dimmer switch actuation (ON/OFF), great call Thanks. Now on to the oil pressure gauge INOP problem....
Ok it was a bad ground causing the the volt meter issue and I found it through the dimmer switch actuation (ON/OFF), great call Thanks. Now on to the oil pressure gauge INOP problem....
Torxhead
Always Off-Roading Jeeper
For a little bit of ground help on the dashboard electronics, run a wire from the upper battery side on the firewall to the dash to a instrument cluster mounting bolt. The nearest factory ground connection is at the firewall near the battery in the engine compartment. This will help get a connection from the battery ground to the instrument panel. CJs are well known for poor grounds, especially after 30+ years of dirt, corrosion, and coats of paint.
dwickens1
Jeeper
Thanks TORX, I'm an aircraft Mech by trade and its odd and on my list to put a negative Bus on the firewall to dumb it down to my level and meet my OCD needs