My new boat does not have reverse lights and I've checked all the fuses and no reverse lights. So I figured I need my truck lights checked to match my trailer connections. Does anyone in Forney or Terrill know where I can get this done?

Do you have a test light or voltmeter? It's not hard to check.

First, do you have a 4 wire flat, 5 wire flat, or round trailer wiring connector? Only the last two support the blue wire for reverse. Do you have disc brakes on the trailer? If so, the important reverse lock-out solenoid may not be working if the reverse lights aren't on since that wire controls both; this is not good as you can damage brakes in this circumstance.

Look for white wire on trailer connector, trace from trailer if necessary. That's Ground. Look for the blue wire on trailer connector, trace to truck's connector. Test lamp between those two contacts is the reverse lamp circuit. Have someone put the vehicle in reverse. If a test lamp doesn't illuminate, you don't have a reverse wire connected on your truck's connector.

Do all other lamps work correctly? This would tell us that Ground is good as a starting point.

it's the 2' round plug on the truck and boat and all other lights work on the boat. I have a volt meter but not sure how to use it in this situation.

Put the voltmeter on "DC Volts" selection. Have someone start the vehicle and put it in reverse with the parking brake set and great care, obviously. You want to look for 12V present between the yellow and white contacts of the truck's connector. See image below. As a test of your procedure, measure between white and red (a brake light) where you should also see 12V while someone is holding the brakes.



Note: Color code on the connector is NOT the color of the wire you should see on the trailer. What's on each contact is all about location on the keyed connector that can't be plugged in upside down.

That's great help there, thanks a lot

Did you figure it out?

No sir, starting to make me upset, having to put that tool in to back up. I appreciate the help.

Did you check voltage on the center pin of the truck's connector to the one shown in white? You should get 12V there when the truck is running and in reverse. You can even use a cheapie auto parts store test light for this test. If you don't have 12V between the two contacts, your truck is the problem. Any trailer repair shop or automotive shop can easily fix this.

On the trailer connectors the center contact is for the brake lock-out solenoid near the trailer tongue. It is a small "can" looking part that has hydraulic brake lines running through it. Make sure the wire from the trailer connector is actually connected to this (not broken).

You said "new" boat. Is that dealer new or new to you? I ask because if a used boat, it is quite possible that the lock-out solenoid is bad. Test it in a manner similar to testing the truck. Use voltmeter or test light with truck running, in reverse, trailer connected. The wire connection at the solenoid should have 12V when you have the GND test lead on the mounting bolt/bracket for the solenoid. (They get Ground internally from the mounting bracket.) If you read 12V there, but the trailer brakes are locked up, you have a bad solenoid.