Yamaha Front Wiring Harness
 

The headlights on my 2020 cart have been flickering at start up speed. The guy from Carts and Clubs says its the front wiring harness and will cost a good chunk of change to fix. He further said it's an accessory and not covered under warranty. Anybody else have this problem? It's more of a nuisance at this time.

Check the bayonet plug connection make sure they are tight.

Agree with Kee.

Doubt the harness is the issue, more likely than not a connection.

Thanks, this thing has low miles and hours. The kid that changed the oil said the harness has been a problem and that they install an upgraded one.

I would also check the ground connection, especially if both lights are going out at the same time. The other common components to check, the headlight switch and the connections for this switch. The main fuse and the key switch also are common to the engine, so you would see the engine stutter or shutdown. I have seen problem with wiring harnesses and the older style Halogen lights, but not the newer LED lights.
If you are a DIYer, you can turn on the headlights and jiggle the wires while observing the headlights, you can also remove the dash panel and do the same with the wiring in there. If you find the loose wiring, then you should be able to apply a fix.

Can you find wiring diagram? You’re headlights, meaning both of them? First would check ground and connectors for corrosion. Look for wires chafing. If they are good them you have to get multimeter and trace each wire from point a to point b. You can also back probe to check voltage. When doing this need to wiggle harness see if voltage fluctuation? Which might mean break stains in particular wire. That’s why it may be costly, time consuming to actually find fault?

Like others has said it both are blinking I would suspect grounding/corrosion problem?

Check the wire harness assembly part number. If yours is J0K-H2590-00-00, it has been replace by part number J0K-H2590-02-00. The new part should cost around $250.00

The typical Yamaha wiring diagram does not cover headlights, turn signals etc, as these are not on a typical golf cart. As noted above the wiring harness foe these items is usually an after market product, and therefore could be different between manufacturers. I have helped several neighbors with golf cart electrical problem and have not found any 2 wired the same, even models of the same year.
I hope the OP keeps us up to date if they get a chance to follow the previous suggestions.

1. The part I recommended is OEM.
2. The Yamaha Shop Manual has the wiring diagram. (Yes, I have a shop manual for my golf cart. Bought it when I bought the cart.)

If its a Carts and Club cart- they use an aftermarket harness, and that is where the issue is. Carts and Clubs has always been proud about how they use their own wiring harness. They havent held up well are there are issues.

My 2020 does the same thing. I was told it is in the amount of voltage that is delivered to the headlights at startup. It is not a short as it never happens at any other time, only when getting going from a dead stop.

The technician said that since the voltage was 12 volts are above on startup that would indicate the wiring harness issue. Yesterday when I took it out the voltage went below 12 volts at startup and both headlights flickered. Played around a little in the afternoon with the wires but did not get any flickering. Interesting to see a Curt control box under the lid.

OP, check you battery. If you have a digital voltmeter, you should have over 12 VDC with everything off, and around 14 VDC when the cart is running (have a friend look at the meter while you drive). If you are getting readings below this, I would take the battery out and go to an automotive store and have it load tested, and replace if necessary. We had the battery on ours go and the cart would hesitate on starting, new battery fixed that immediately. We never noticed any flickering on the headlights, but ours is a 2017 with a NON Yamaha wiring harness and probably the same for the lights..

All good suggestions but it all boils down to Carts and Clubs. Only they have the wiring diagram for their carts as they buy the carts from Yamaha without the complete Yamaha wiring system. They do their own in-house wiring. They do this to save a buck. I would press Carts and Clubs a little harder to help with this. Good luck.

I agree with you, if it was a bad harness they probably wouldn’t come on at all. It’s a connection that’s barely making contact. Surprised the dealer didn’t check it for you. Unless the owner insisted it was the harness so the dealer gave you a price on the harness. You can check the connection yourself it’s easy!