• Welcome to Jetboaters.net!

    We are delighted you have found your way to the best Jet Boaters Forum on the internet! Please consider Signing Up so that you can enjoy all the features and offers on the forum. We have members with boats from all the major manufacturers including Yamaha, Seadoo, Scarab and Chaparral. We don't email you SPAM, and the site is totally non-commercial. So what's to lose? IT IS FREE!

    Membership allows you to ask questions (no matter how mundane), meet up with other jet boaters, see full images (not just thumbnails), browse the member map and qualifies you for members only discounts offered by vendors who run specials for our members only! (It also gets rid of this banner!)

    free hit counter

DIY: MFI Trailer Wiring and Backup Flood Lights

KXCam22

Jetboaters Captain
Messages
1,083
Reaction score
879
Points
217
Location
Kamloops BC
Boat Make
Yamaha
Year
2008
Boat Model
AR
Boat Length
23
Face it. The MFI trailer wiring and lights are crap. The first summer I had my boat I spent more hours working on the trailer lights than on the boat. I did two things to fix this. LED lights are a must since the stock waterproof lights I had only succeeded in keeping water in. The seconds was to install a dedicated ground wire down each side of the trailer and connect it to all the lights. This prevent any corrosion induced grounding issues. Here are some wiring diagrams I made. Hope they are helpful. Also note on the ultimate wiring diagram the additional backup flood lights. I added these to help when backing into camping spots in the dark. They also work under water when loading the boat in the dark. Cam
light mods 03.JPG light mods 06.JPG
 

Attachments

Bruce

Jetboaters Fleet Admiral
Staff member
Administrator
Messages
11,574
Reaction score
11,405
Points
657
Location
Royal, AR
Boat Make
Yamaha
Year
2007
Boat Model
SX
Boat Length
23
Those are impressive diagrams!

I am curious why you hooked up your backup lights to pin 4 with a switch instead of 7?

I run a pair of backup lights off of pin 7 on my utility trailer. Were you worried that there might not be enough amperage to disengage the brake and light the bulbs?
 

txav8r

Jetboaters Admiral
Staff member
Administrator
Messages
6,587
Reaction score
3,213
Points
382
Location
Lake Ray Roberts, Texas
Boat Make
Boatless
Year
NA
Boat Model
Other
Boat Length
NA
Very nice Cam!
 

leatherneck33

Jet Boat Addict
Messages
55
Reaction score
42
Points
107
Location
Wylie, TX
Boat Make
Yamaha
Year
2010
Boat Model
AR
Boat Length
24
I would like to setup the backup lights, what lights did you use? Thanks for posting your setup.
 

-klb-

Jet Boat Addict
Messages
65
Reaction score
23
Points
97
Location
North Texas
Boat Make
Yamaha
Year
2005
Boat Model
AR
Boat Length
23
I would think that using pin 4 is so that you can switch them on and leave them on while loading the boat at night.

I might consider using a double throw switch to select between pins 4 and 7.
 

KXCam22

Jetboaters Captain
Messages
1,083
Reaction score
879
Points
217
Location
Kamloops BC
Boat Make
Yamaha
Year
2008
Boat Model
AR
Boat Length
23
KLB is right. Pin7 is the always on trailer power wire. I only use them in reverse when I choose and with the switch they will stay on with the truck lights off. The lights are just cheapy sealed beam tractor lights, $5 each but sealed so they work underwater. In theory I think they are too powerful to legally be used as reverse lights on pin 4. They lights have proven to be extremely handy. I was rewiring anyway so a couple of extra wires pulled was easy and there was a natural no-work required mounting spot. Cam.
 

Scottintexas

Jetboaters Admiral
Staff member
Messages
3,734
Reaction score
2,858
Points
297
Location
Corinth, TX (DFW)
Boat Make
Yamaha
Year
2007
Boat Model
AR
Boat Length
23
great write up, thanks for the diagram, for others in the future if you're having trouble with a ground on a trailer with a folding tongue you can try run a jumper from near the hitch where the connector grounds around it to the ground of the first marker light,
 

Julian

Jetboaters Fleet Admiral
Staff member
Administrator
Messages
13,477
Reaction score
11,119
Points
712
Location
Raleigh, NC 27614
Boat Make
Yamaha
Year
2016
Boat Model
242X E-Series
Boat Length
24
@KXCam22 What brand/model LED lights did you switch to? Just had my first light failure (11 hours from home of course) and now need to buy some LEDs to replace the stock turn/brake/running lights.....
 

KXCam22

Jetboaters Captain
Messages
1,083
Reaction score
879
Points
217
Location
Kamloops BC
Boat Make
Yamaha
Year
2008
Boat Model
AR
Boat Length
23
I used some cheap Grote ones. A friend works at a peterbuilt shop and got the over 80" trailer kit for me cheap. They fit (with a few bolt hole mods), they work and they still work today - haven't looked at them for 2 seasons at least. I haven' replaced the small side marker lites yet. Those seem to hold up. My stock MFI lites were beyond horrible. I even replaced the ones on my dirtbike trailer a week later just to avoid any future maint hassle. Its a worthy switch. The LED optronics are nice and a perfect bolt on. They were ridiculously expensive in my town, hence my using the Grote kit. The Grote lites are the same size as the stock ones but required drilling one different attachment bolt hole. This is the kit.

Cam
 
Top