2004 Sprinter wiring diagram?

[VirtualMe]

Happy new year folks!

Would anyone happen to have a contact that could acquire a trailer wiring diagram for a 2004 Sprinter 5th wheel? I find myself in a position to try and figure out what a previous owner did, and it would sure make my life a bit easier.

Looking under the pin box on my Sprinter, I found a pair of toggle switches connected to a metal junction box. On one side of the junction box is the trailer cable that connects to the tow vehicle. On the opposite side is the wire bundle that runs into the trailer frame and the two wires for the break break-away.

Playing with the toggles, I discovered that one toggle stops the power flow to the trailer lights while connected to the tow vehicle. The second toggle seems to do nothing. I couldn't for the life me think of any legitimate reason for this. I cracked open the junction box to take a look and was unsurprised at the rats nest of wires, wire nuts, splices, and black electrical tape. I also found what I assume is a relay used for the flashers, but I'm not sure.

If your interested, you can see a few photos of what I found on my G+ profile at http://bit.ly/za0w3a.

My plan is this spring, I want to pull all of it out and rewire it with soldered and shrink wrapped connections. Unless I can think of any reason at all why they were installed, I will also eliminate the toggle switches.

I really don't want to have to tone and trace all of the wires individually, and would love a diagram if anyone knows where I can get one.

Any help is greatly appreciated.

Thank you!

Gerry

[rjsurfer]

Looking at wiring and where it was placed I'm thinking that was not factory work.

Looks like a previous owner had done some mods, maybe you could contact the previous owner? worth a shot.

Ron W.

[SteveC7010]

Looking at your pics, it looks like there is an automotive flasher in there. I bet the PO installed a switch to turn on the trailer's marker lights while in camp. It's a common thing to do among some campers.

BTW, that "rat's nest" is Keystone standard less the switches, flasher, and associated added wiring. I will go one step further, and say that most RV manufacturer's do a bit of that poor organization in their wiring in one place or another in their products.

So, the switch that is connected to the flasher can be removed easily by disconnecting the switch, flasher, and whatever wire goes back to the TT's pigtail wiring that comes in on the front side of the box.


If the other switch just disconnects the TV's 12 vdc charge line, then just remove it and tie the wires together.

The color coding on the pigtail side should be correct to this chart:


As always, when working with this stuff, disconnect the ground side of the battery and remove the pigtail from the TV. Also unplug the shoreline.

[mhs4771]

As for wireing diagram, forget. It all depends on which assembler did the wiring on your unit. Seems there is no standard wiring for any of the Keystone products, most likely industry wide. I agree with the other posts, sounds like the flasher for the marker lites deal. Some think it's kool, what ever floats your boat or should that be RV.

[JRTJH]

If it's any "consolation", the inside of your junction box looks exactly like the inside of my junction box except for your additional flasher and switches. Mine is exactly as it came from the factory without any additional "rats nest" added by me. Seems Keystone includes the rats nest "free of charge" to only it "best customers" LOL

As for a wiring diagram. Most RV manufacturers build on an assembly line, but don't follow "automotive" line procedures, ie: at Ford/GM/Dodge every wire is placed in the same location, every switch is installed the same way, every fastener is installed as all that were done before it.... In RV's, as a unit is pushed down the line,different workers install components in "their" best idea of what will work, route wires, lines, etc where there's enough space, sub red wire for green if no green is available, use twist caps in place of crimp caps because that was what they had in the unit (too much trouble to step outside to the supply bin).

While this may not affect the actual "functional quality" of the vehicle, it sure does make for nightmares when an owner or repairman tries to troubleshoot a problem.

When I installed the LED tail lights on my Springdale, rather than finding the standard trailer harness wiring colors (green, yellow, black and white) I found red, white, blue and orange. And, just so you know, those were not the wire colors at the trailer/tow vehicle pigtail....

Good luck with your switches and relay, as said earlier, it sounds like (and from your pix on the website) looks like the previous owner added a flasher and switch so he could have the running lights flash while on the roadside and/or in a campground. Why? on the roadside, it's probably safer, in the campground, so the pizza delivery guy can find him LOL

[trucker LOU]

I also had std. equip. rats nest that failed on first trip out. Rewired pin box with larger box and included fuses. If I can figure this out I will post pics. LOU.

[trucker LOU]

P.S.--I also cleaned up tangled mess in front compartment of my 242fwrlss and moved the landing gear fuse from behind the battery to beside the switch.

[VirtualMe]

Originally Posted by trucker LOU

I also had std. equip. rats nest that failed on first trip out. Rewired pin box with larger box and included fuses. If I can figure this out I will post pics. LOU.

Nice job.. I had thought about making more of a "power distribution center" when I redid it. I like the idea of the fuses you put in place, but am curious what you think of putting in circuit breakers instead?

[SteveC7010]

Originally Posted by trucker LOU

I also had std. equip. rats nest that failed on first trip out. Rewired pin box with larger box and included fuses. If I can figure this out I will post pics. LOU.

Lou:

Nicely done! (Another project for my spring job jar, too!)

Gerry,

Rather than the older AGC glass fuses, I am thinking the newer style ATO, ATC, or ATM fuses.


Not sure about circuit breakers in this application. Anybody else have any thoughts on this?

[JRTJH]

Steve,

I tend to believe that automatic reset circuit breakers are good in applications where they are monitored during use (the time when they are actually protecting the circuit) but I also think they can be hazardous if placed in an application where they are not monitored. Example: Automatic circuit breaker in running light circuit: Should there be a short to ground, the circuit would continue to reapply power possibly increasing the potential for fire, more damage by overheating and melting wire, etc. Or in the refrigerator circuit: it could open to protect the the appliance, but if it continues to reset and apply power, it could lead to further damage.

As for fuses, the older glass fuses are reliable in a dry, noncorrosive environment, but they are less reliable than the newer fuses in wet, dirty environments.

I think autoreset minibreakers are a good thing in landing gear circuits and other applications that need protection during use, but don't apply power otherwise. Manual reset circuit breakers do not fit into the "unmonitored circuit" category I'm talking about.

Manual reset breakers and/or ATM fuses are better able to protect "unmonitored" applications and probably are a better choice over glass fuses because they are currently used in most tow vehicles and RV's and using them in additional applications helps simplify the amount of inventory and the various types of fuses you'd need to carry on the road to manage power needs.

[SteveC7010]

John,

Fully agree on the logic for breakers not being optimal for this particular situation. You described it much better than I could have.

I just did a bunch of internet searching, and can not find a fuse block for ATO, ATC, or ATM fuses where each fuse has its own in and out terminals like the glass fuse block that Lou used. The only ones I can find have one input and a bunch of individually fused outputs; more like a distribution box. There are some for the much more expensive ANL fuses, but I am disregarding them for now.

Since that electric box is pretty well protected up under the pin box (I am rethinking here) it should be OK for moisture and dirt issues. If dirt and moisture was a problem up there, it would be very easy to swap out that steel box for a plastic, weather-proof, outdoor box of the same size or even a bit larger.

Since the glass fuse holder blocks and fuses are readily available and inexpensive at that, they're likely the best bang for the buck in this application.

[JRTJH]

Steve,

Here's a link to one ATO fuse block with independent circuit in/out terminals:

http://www.ebay.com/itm/Fuse-Block-6...item5647bef967

Granted, it's 12.95 plus 5 shipping, I'm sure the same block can be found locally at Radio Shack, etc or possibly other sources cheaper than this Ebay source, but at least it's a start for you. They are available

[SteveC7010]

Originally Posted by JRTJH

Steve,

Here's a link to one ATO fuse block with independent circuit in/out terminals:

http://www.ebay.com/itm/Fuse-Block-6...item5647bef967

Granted, it's 12.95 plus 5 shipping, I'm sure the same block can be found locally at Radio Shack, etc or possibly other sources cheaper than this Ebay source, but at least it's a start for you. They are available

John, that will do quite nicely! Thanks for the hunting. I'm not uncomfortable with the price at all. But it's worth a look at RS, etc. before deciding where to buy.

Edit: That same seller has the Summit Racing fuse blocks in 4, 6, 8, and 10 circuit models.

Thanks!

[trucker LOU]

I used glass fuses because the only fuse blocks for flat fuses I could find had a common hot lead. I needed separate hot leads .---LOU---

[JRTJH]

Originally Posted by trucker LOU

I used glass fuses because the only fuse blocks for flat fuses I could find had a common hot lead. I needed separate hot leads .---LOU---

Lou,

That was also Steve's problem. He could only find the common hot terminal block. Really, it's just a multiple distribution block. What I showed him on Ebay was the multiple circuit terminal block, pretty much the same as you used except for mini fuses rather than glass fuses.

In reality, what you have will work well, my only advice would be to check the glass fuses (especially the solder joints) for corrosion about once a year. With the mini fuses, there's not as much potential for corrosion.

[Festus2]

Steve:
You might want to check out marine supply stores as they usually carry or stock a wide range of fuse holders and terminal blocks. But like RV suppliers, they aren't the cheapest place to shop!