48v CC digital voltmeter install problems

[easytiger864]

New member here, I've searched several times and I haven't found any mention of this type of issue. Please forgive me if I've missed it in the searches.

Here's what I've got. 1998 Club Car DS 48v and I added one of these digital volt meters off of Amazon. (see pics) I have the voltmeter wired to the battery ground and to the switched part of the key switch so it turns off with the key. I charged the cart fully and turned it on and it's reading 46.4 volts. So I check the batteries with my handheld meter and I'm getting 49.8 volts. I measured the wires going to the new voltmeter with my handheld meter and I also get 46.4 volts, so I know the new voltmeter is accurate.

My question is why would the always hot side of the key switch read 49.8 volts like the batteries and the switched side read 46.4 volts? Is my key switch bad? I don't want to have to wire the voltmeter straight to the battery pack with a toggle switch if I don't have to.

Thanks for the help.

Pics attached showing the readings.

[TahoeDawgZ71]

Originally Posted by easytiger864

New member here, I've searched several times and I haven't found any mention of this type of issue. Please forgive me if I've missed it in the searches.

Here's what I've got. 1998 Club Car DS 48v and I added one of these digital volt meters off of Amazon. (see pics) I have the voltmeter wired to the battery ground and to the switched part of the key switch so it turns off with the key. I charged the cart fully and turned it on and it's reading 46.4 volts. So I check the batteries with my handheld meter and I'm getting 49.8 volts. I measured the wires going to the new voltmeter with my handheld meter and I also get 46.4 volts, so I know the new voltmeter is accurate.

My question is why would the always hot side of the key switch read 49.8 volts like the batteries and the switched side read 46.4 volts? Is my key switch bad? I don't want to have to wire the voltmeter straight to the battery pack with a toggle switch if I don't have to.

Thanks for the help.

Pics attached showing the readings.

When you say you have the negative side of the meter hooked to "battery ground", where exactly do you mean? On the actual battery post? Or on a ground block?

[easytiger864]

Originally Posted by TahoeDawgZ71

When you say you have the negative side of the meter hooked to "battery ground", where exactly do you mean? On the actual battery post? Or on a ground block?

I've tried both with the same results. I currently have it wired to the ground block under the driver seat.

[TahoeDawgZ71]

Originally Posted by easytiger864

I've tried both with the same results. I currently have it wired to the ground block under the driver seat.

I'm not sure of your setup, but the ground block on a DS is typically powered by a voltage reducer (for your lights) on the negative side of the circuit. The black negative wire from your meter needs to be hooked directly to the battery or the "B-" post of the motor controller. Otherwise you're going to be reading reduced negative voltage.

With your multimeter set to 200VDC, Red probe on the green wire on the key switch, and black probe on the MAIN NEGATIVE battery post (Negative post on battery number 6, rear, driver's side battery on DS), what kind of voltage do you see?

[easytiger864]

Originally Posted by TahoeDawgZ71

I'm not sure of your setup, but the ground block on a DS is typically powered by a voltage reducer (for your lights) on the negative side of the circuit. The black negative wire from your meter needs to be hooked directly to the battery or the "B-" post of the motor controller. Otherwise you're going to be reading reduced negative voltage.

With your multimeter set to 200VDC, Red probe on the green wire on the key switch, and black probe on the MAIN NEGATIVE battery post (Negative post on battery number 6, rear, driver's side battery on DS), what kind of voltage do you see?

You are THE MAN, David. I just went and checked the switch and I'm getting 49.9v on my multimeter. I'll extend the wire to the negative battery terminal tomorrow after work.
Thanks again for the help.

[TahoeDawgZ71]

Originally Posted by easytiger864

You are THE MAN, David. I just went and checked the switch and I'm getting 49.9v on my multimeter. I'll extend the wire to the negative battery terminal tomorrow after work.
Thanks again for the help.

I could see the problem from here.

[TahoeDawgZ71]

If your meter is wired directly from the meter to the pack, the only thing that can be wrong is the meter. I would replace it.

[Sergio]

Measure the voltage directly on the back of the dash meter connections.

If the multi-meter reads different and you sure of the accuracy of your multi-meter, the dash meter is bad.

If the voltages read the same, you have a wiring problem between pack and meter.

[NCPW]

Will do. Thanks for the advice!

[Mikefili]

I have that same digital meter on my 48 volt cart. The cart came with a bar type battery meter so all I did was pull the spade fittings off that and plug them into the digital. I did not word it so I do not know where it is wired to although the wires Ho into the wire harness. They do not go to the key switch and the meter is on all the time. At rest if reads 51.50 volts, under full load it goes down th 43 or so and then recovers to 46 or so on flat ground. When stopped it goes back up to 51 or so. My question is at what voltage should I head back to the charger?