What does a Golf Cart Solenoid do?
Before trying to understand the symptoms of a solenoid going bad in you golf cart, let’s review what they are supposed to do when operating properly.
Technically, in fact, a solenoid is a shape – a shape in which the length of something coiled is longer than the diameter of the coils. In engine starters, this refers to the smaller motor that piggybacks on the starter … as that smaller motor contains a wire coiled many times around a metal bar.
For a gas golf cart, the function of the solenoid in a golf cart motor is to use a small amount of electricity (made possible by turning on the ignition switch) to close two heavy-duty contacts that are needed to get the starter turning over. It also functions in the same way with an electric golf cart.
Step by step, it looks like this:
When you turn the ignition key, a small amount of electricity goes to the solenoid. The solenoid uses that small amount of juice to close two heavy-duty contacts that allows a large jolt of electricity to pass through the starter. The solenoid also sends a pinion gear forward, which is the device the starter uses to turn over the flywheel. Once the engine engages, a spring brings the pinion gear back to the starter, where it remains idle until you need to restart the engine at some point.
So, in review, the solenoid does two things:
- It acts as a switch that permits a large amounts of juice to go to the starter.
- And it acts as a mechanical device that puts the starter pinion gear into position, so when the starter turns over it will be engaged with the flywheel just long enough for the engine to catch.
For an electric golf cart, it functions in the same way, however there is no starter. The solenoid is simply there to allow electricity to flow freely to the controller and motor which will result in a running golf cart.
So, what are the symptoms of a bad solenoid on a golf cart?
In a gas golf cart, The larger contacts could fail to release, which means the starter will be operating even if you turn the ignition switch to off. In addition, the spring that pulls the pinion back to its resting position could wear down leaving the starter engaged continuously. (Starters are supposed to get the flywheel moving, then back out of position – disengage.)
Like any switch that relies on wiring, the solenoid could also just wear out due to overheating. This might cause it to fail to retrieve the pinion gear.
Knowing that, when the solenoid starts failing, how do you know it and what’s going on?
On a gas golf cart, the most common symptom is the starter failing to engage – so the engine doesn’t turn over – while all you hear a series of very futile clicking sounds.
On an electric golf cart, the most common symptom is the solenoid is not delivering electricity to the controller when the vehicle’s ignition is turned on. In normal operating conditions, the solenoid clicks on and off with the ignition switch. A failing solenoid will generally not click.
Two things could be going on here. The solenoid might not be getting enough electricity to do its work – which could be caused by loose connections, a weak battery or the coil wearing out.
Secondly, the contacts could begin to wear out from overheating or exposure to high levels of current. This needs to be fixed right away if possible, because this causes continuous use of the starter. If not caught in time, the solenoid and the starter will both need replacement.
How to test for a bad solenoid in your golf cart
If you’re a do-it-yourself-er (of course you are), here’s what you can do.
Before starting work, a couple of items/tools will be recommended prior to starting. The list is as follows:
- a multimeter or voltmeter
- a 1/2” or similar in size wrench
- electrical tape
- safety glasses
First rule here: when you test the starting system, first disconnect the cables that go to the larger solenoid terminals from the starter (gas) or controller (electric). When you do this, use electrical tape to seal the cable ends, so they won’t form a circuit by accidentally touching each other or connecting through a metal conductor inadvertently. Doing this will ensure the vehicle will not run while testing the solenoid.
Once you’ve disconnected the cables safely – using your multimeter – use the voltmeter on the ohms setting and touch each large terminal with the probes with the key turned off. You should get a zero reading.
Now try the same thing with the key on and the cart set to forward travel (not reverse).
Step on the gas and listen for a clicking sound.
If you get a clicking sound, look for a reading of less than 0.4 ohms. If the reading is higher, the solenoid is not working and needs to be replaced.
On an electric golf cart, if the solenoid is silent – no clicking – use the setting voltmeter to DC volts using the 200 range. First, turn on the ignition while looking for a reading on the smaller terminals. If nothing is appearing, then press on the accelerator. If the needle doesn’t move, then the problem is not with the solenoid. If it jumps and displays full voltage, then the solenoid is the problem and should be replaced with a new one.
We hope this article has helped you understand the symptoms of a bad solenoid on a golf cart. If you have any questions please feel free to ask them in the comments below.