Are there any Switch Savants Here?

RNajarian · RNajarian's Garage

Silly question, of course there are. Hopefully someone will able to give me some insight on a project of mine.

I am directly wiring a volt meter to the battery pack of my 48 volt (DC) golf cart. Though it has minimal electrical draw I would like to be able to turn it off when not in use. My cart has a panel of 4 switches, two of them are used for the 12v headlights and 12v fog lights. There are two unused switches.

My question is how can you tell if the switch is rated to handle 48 volts? I’ve included a couple of photos. Like an idiot I forgot to pop one of the switches out to see if there is anything printed on the side which may indicate rating. However, when I am able to get back to the cart what and where should I look on the switch to see its rating.

OR, can/should I wire the switch to the ground with the hot positive connected directly to the voltmeter?

Thanks for your insight.

Sorry for this bad photo, it is all I have right now of the rear of the panel.

1990C4S · 07-12-2021, 07:53 AM

48 Volts will not be a problem. On a voltmeter you are switching almost zero current.

Why not connect the voltmeter to your 'ignition', isn't there an 'on/off' for the cart?

RNajarian · RNajarian's Garage

Quote:

Originally Posted by 1990C4S

48 Volts will not be a problem. On a voltmeter you are switching almost zero current.

Why not connect the voltmeter to your 'ignition', isn't there an 'on/off' for the cart?

There is an on/off switch. From what I read the most accurate measurement is a dedicated circuit with nothing inline on the current. That’s reason one, reason two is the switch is hard to get to and it’s easier this way.

So I am assuming the recommendation is switch the positive lead?

Pazuzu · 07-12-2021, 08:20 AM

Did that switch package come with the vehicle? Whats' the chance that it's internally converting from 48V to 12V, since you mentioned 12V lighting being powered by it. Or, it might be feeding relays that convert to 12V.

Reason being, the other two switches might not give you the volt reading you're looking for, unless you can actually get in and connect to the switch leads themselves. If you connect to some pre-existing pigtail harness, it might be sending out 12V not 48V. Easy enough to check.

john70t · 07-12-2021, 08:47 AM

Quote:

Originally Posted by RNajarian

OR, can/should I wire the switch to the ground with the hot positive connected directly to the voltmeter?

The switch after the load (voltage gauge) would be safer I believe.

The VM should be rated for 48V of course.

RNajarian · RNajarian's Garage

I spoke with a guy from the golf cart manufacturer’s parts department. He told me the power going to the switch is 48v and is converted to 12v AFTER the switch. However, looking at the wiring diagram it appears to me the power is 12v going into the switch. I’m not near the cart now to verify, but based on what (little) I know about schematics I think I am right 12v at the switch.

Oh and yes the voltmeter is rated at 48v.

john70t · 11:06 AM

I assume it's going to be wired 48V battery--inline fuse--gauge--switch--battery?

I think the entire 12V circuit should be a separate legs and isolated though a step-down transformer or two.
The two circuits shouldn't ever meet.

Take the switch off and DVOM the input wire to find which is feeding it.
Actually if it's a dead console filler switch nothing at all might be hooked up.

(I'm just guessing. Autistic not savant here.)

RNajarian · RNajarian's Garage

The company designed a four switch panel, two are being used, the other two slots have switches installed (which are not hooked up-see photo in first post.)

Your description of the circuit is correct.

dad911 · 11:44 AM

The yellow are all 12v lines, after the DC converter. so 12v at the light switches, 48v at the solenoid and power key.

I'd wire the 48v meter between Blue (pos) and Black (neg) and it will work with the key, or Red & Black and it will work with the solenoid.

1990C4S · 07-12-2021, 12:26 PM

Looks like your instrument panel powers up with the key, and is 48 Volts...

RNajarian · RNajarian's Garage

Quote:

Originally Posted by 1990C4S

Looks like your instrument panel powers up with the key, and is 48 Volts...

Yes that is true. I am considering removing the “instrument” panel all together and use the space for a double DIN head-unit with all the works.

The instrument panel for this model year cart was an all in one gauge that did the following:

Power ON green LED
Low Power Idiot light -red
Turn signal indicators (green LED arrows)
Voltmeter

I have recently installed a traditional speedometer/odometer (cart DID NOT come with this option)

I’m going to put this easy to read voltmeter (the one on the instrument panel cannot be seen from the driver’s seat) right under the speedometer.

. . . and of course what does every golf cart need? Yes, a Bluetooth/DVD player/Navigation unit. I plan on putting something like this in place of the existing radio and instrument panel.

I will utilize the 12v going to the existing single DIN radio and disconnect the “instrument” panel. The only real feature I may be losing is the turn signal indicator, which like the “instrument panel” voltmeter is difficult to see from the driver’s seat.