[Rellhamburger]

When I connect my 5th wheel to the truck all lights except the clearance lights work on the 5th wheel. I am certain that I blew a fuse or relay or something but I have no idea which one and I have checked all fo the ones that I can find and none are blown.

 

[Two Yeets]

Use a multimeter to test your truck's trailer connector to verify it's not your trailer that has a problem. Trailers are notorious for having eletrical issues.

 

[Rellhamburger]

Use a multimeter to test your truck's trailer connector to verify it's not your trailer that has a problem. Trailers are notorious for having eletrical issues.

It’s not the trailer, verified that first. Hitch meter shows that it is the truck.

 

[darkgenerals]

should be two different fuse blocks, not sure which on has the trailer lights but one is located inside the cab and the other is under the hood.

 

[Rellhamburger]

Yea sir I checked both and zero fuses blown

 

[darkgenerals]

That means you get to do the fun part of multimeter to test and confirm power on each power pin and ground on the ground line. Then tracing out the wires not getting power/ground.

 

[Rellhamburger]

That means you get to do the fun part of multimeter to test and confirm power on each power pin and ground on the ground line. Then tracing out the wires not getting power/ground.

I like tested my pig tail plug at the pins which is how I found that it was indeed only my clearance lights that were impacted. However, my issue is trying to find out which fuse or relay in the truck controls this particular function.

 

[darkgenerals]

Have you looked over the service manual? This should get you started on what and where to check.

https://www.nicoclub.com/nissan-service-manuals#titan

 

[Rellhamburger]

Line tested the receptical on my truck.

 

[Rellhamburger]

Have you looked over the service manual? This should get you started on what and where to check.

https://www.nicoclub.com/nissan-service-manuals#titan

Have you looked over the service manual? This should get you started on what and where to check.

https://www.nicoclub.com/nissan-service-manuals#titan

yes I spent all day Saturday and Sunday reading that absolutely useless service manual. As it only directl addresses the basic fuses lights, cigarette lighter etc. it does not isolate which fuse or relay controls the marker lights on the attached vehicle. Spoke with Nissan this morning and Accor to them there is no way to pinpoint which fuse/ relay does what without them doing a diagnostic test to the tune of $150.

 

[realbored]

Not sure why you had trouble reading the wiring diagram for the trailer tow system but terminal number six in the connecter receives power from fuse # 52 which is a 10 amp fuse in the IPDM. If the fuse is good check to make sure that there is power coming out of the IPDM at connector 123 terminal 50 (brown wire in the 8 pin brown connector). If there is power there it goes through trailer tow relay 1(they rarely go bad) before the SMJ connector on the passenger side frame rail. I would check there next as that is the most common place the wiring goes bad. You need to check pin location 44C in the SMJ. Pages TTS 10 -18 in the service manual shows the wiring diagram and pin locations for all connectors in the system.

 

[NavyCuda]

Not sure why you had trouble reading the wiring diagram for the trailer tow system but terminal number six in the connecter receives power from fuse # 52 which is a 10 amp fuse in the IPDM. If the fuse is good check to make sure that there is power coming out of the IPDM at connector 123 terminal 50 (brown wire in the 8 pin brown connector). If there is power there it goes through trailer tow relay 1(they rarely go bad) before the SMJ connector on the passenger side frame rail. I would check there next as that is the most common place the wiring goes bad. You need to check pin location 44C in the SMJ. Pages TTS 10 -18 in the service manual shows the wiring diagram and pin locations for all connectors in the system.
View attachment 48162

Do you happen to know which section I would find the obd2 connector pinout?

 

[darkgenerals]

Do you happen to know which section I would find the obd2 connector pinout?

By law obd2 connectors for the most part are standard across all vehicles. Unless Nissan is adding some special pins, all of the canbus, power and data lines are going to be in the standard spot. A google search for obd2 pin out will get you a majority of the way there.

 

[NavyCuda]

By law obd2 connectors for the most part are standard across all vehicles. Unless Nissan is adding some special pins, all of the canbus, power and data lines are going to be in the standard spot. A google search for obd2 pin out will get you a majority of the way there.

I did look at that, but the obd2 connector I'm using bridges the ground/chassis signal and I'm hesitant to plug in my prototype board until I know if that's going to be a problem.

 

[darkgenerals]

Better to be safe than sorry. Reading through the manual is kind of a pain, but it’s definitely in there.

 

[realbored]

Do you happen to know which section I would find the obd2 connector pinout?

Not sure if this helps but this is page EC-149. You may find more info in the EC section but CAN related information is typically found in the LAN section.

 

[Two Yeets]

Do you happen to know which section I would find the obd2 connector pinout?

I used realbored's comment to help me, as I overlooked it earlier. Pretty sure this is it. EC-170.

 

[NavyCuda]

View attachment 48167

I used realbored's comment to help me, as I overlooked it earlier. Pretty sure this is it. EC-170.

Well that settles it. also... ahh... that looks like three can buses?! In any case I wasted a bunch of time making a connector and worse I setup my connector to use an 8 conductor rj45. Going to have to order some new obd2 connectors. Why didn't I ask this question before I soldered the connector together?!