Running Lights/Tail Lights blowing SUV fuse

LisaMarie81 · 08-03-2016, 08:19 PM

Hi there! broke this off another thread of mine where I had a series of questions. This one has gotten more complicated.

We have a 2014 Roo 233S. Just purchased it a few days ago. The gentleman we bought it from had it on a seasonal site in 2014 and 2015, but did not use it this summer. It is still winterized and was stored at his home.

Here's the situation: Running lights and tail lights do not work on Roo. They trip/blow the fuse in my SUV immediately

Here's what we've found:
1) we have a PUP - tail lights and running lights work fine on that when hooked up (we did that tonight during trouble shooting as a sanity check, so it's most likely not the car)

2) we did a continuity check between all pins and ground on the RV cable and all check out. Meaning we DO have continuity (full circuit) and no shorts in the RV itself. (assuming if the short was in the RV circuitry continuity would not exist)

3) we removed all light bulbs before we did step 2 for 2 reasons - a) to assure there wasn't some "rogue" bulb causing the issue and b) I read somewhere it's possible to have too many lights for the fuse in your vehicle. Bulbs out - eliminate both issues

4) So.....we check the SUV fuse - good, start the car - good, plug the RV in (with NO bulbs in any tail lights or running lights) - fuse blows immediately. (FYI - same results if it's already plugged into car first then we start the car)

My Initial thoughts? The circuit is good (i.e. no shorts in the RV or we would not get a continuity reading), Our Gnd is good in the RV cable (because blinkers, brakes, etc all work).

Possible that the pin on the positive of the tail lights/ running lights in the plug bad? corroded? not positioned correctly?

Questions - can the back shell be taken off easily? Can you access this "cord" pins/wires anywhere else easily before it breaks off to the lights? Does anyone have a schematic of how and where this goes in the RV to trouble shoot it beyond the cord.

Edited to add this last question - is there a fuse within the RV for this cable (i.e. running lights, blinkers, etc) or is the only fuse for this cable within my SUV??)
Thanks for listening!

youroo · 08-03-2016, 08:29 PM

I would not rule out "Mr Mouse" they love to chew on Wires and since it was a Seasonal it leads more that way also! Hot bare wire against the metal frame is instant short!

Youroo!!

LisaMarie81 · 08-03-2016, 09:03 PM

Thanks Youroo,

But.....seasonal with mouse deterrents up the wazoo. It's everywhere in this rig
but more importantly - if a mouse chewed a wire wouldn't I get zero continuity at the RV plug? we did get a positive continuity check on the RV plug (no car involved) from the tail light/running light positive to the plug ground which means that whole circuit should be good? right? (i.e. - no chewed wires).
Please bear with me if that is not correct, but I'm banking on the fact that we got continuity in the circuit.

rockfordroo · 08-03-2016, 09:14 PM

With all the bulbs removed, I'm not sure why you think you should be getting "continuity." Note that "continuity" is 0 ohms resistance. An open circuit is "infinite" ohms resistance.

Sounds like you're getting a short to me. If you're on the trailer plug and you read the tail light pin to the ground pin, with the tail light and clearance bulbs removed, you SHOULD get NO continuity (i.e., you should see an open circuit). Same for each of the turn signal pins to the ground pin with the taillights removed. If you're reading "continuity," then there's a short somewhere.

Broadway Joe · 08-03-2016, 09:29 PM

You are under the false impression of continuity. With all the bulbs removed you should have an open (infinite resistance) to ground.

LisaMarie81 · 08-03-2016, 09:31 PM

Now....I'm confused....because - yes with all the bulbs eliminated we should still get a continuity as the circuit still flows with or without the bulbs. Reason for that assumption is that if the bulbs were dependent on the circuit running then every time you have a bad bulb you would lose ALL your lights wouldn't you?
I am under the assumption that the circuit flows through irregardless of the bulb or not. That way when bulb blows the rest of the circuit will still work.

Please bear with me and my stupidity - it's the Christmas tree lights effect in my mind. When 1 bulb on a strand of Christmas tree lights goes out, they all go out. If the RV circuit was dependent on the bulbs then when 1 went out they would all go out - no?

maybe this will help - the ohm measurement was .002 ohms and our voltmeter beeped which it says happens when there is continuity

LisaMarie81 · 08-03-2016, 09:48 PM

Wait....I'm with you now.....an open would constitute no continuity. a short would still register continuity because it may be "touching" somewhere it shouldn't be. (i.e. the frame of the rig).
If that's the case...things just got more complicated....

Broadway Joe · 08-03-2016, 09:49 PM

Rv's and car lighting circuits are parallel circuits. Each bulb has a ground and power circuit. If each bulb was in series like Christmas tree lights you would never find out which bulb burnt out.

rockfordroo · 08-03-2016, 10:10 PM

Quote:

Originally Posted by LisaMarie81

Wait....I'm with you now.....an open would constitute no continuity. a short would still register continuity because it may be "touching" somewhere it shouldn't be. (i.e. the frame of the rig).
If that's the case...things just got more complicated....

Now you've got it. Finding a short can be difficult. You have to follow the wiring until you see something that's not right. Good luck!

youroo · 08-04-2016, 05:58 AM

Quote:

Originally Posted by youroo

I would not rule out "Mr Mouse" they love to chew on Wires and since it was a Seasonal it leads more that way also! Hot bare wire against the metal frame is instant short!

Youroo!!

OK sorry look for Mrs. Mouse!

Youroo!!

LisaMarie81 · 08-04-2016, 06:03 AM

UGH. That's all I've got to say now. Hoping the wiring is easy to trace out under the rig. Haven't crawled around under there yet.

LisaMarie81 · 08-04-2016, 08:10 PM

Just wanted to say the problem has been solved.
After last night I suggested we probe each light outside and measure the voltage coming to it to see if there is a problem. My stubborn husband insisted we go have it looked at....so we did...and...the first thing they did was probe each light to measure voltage.

Long story short - it was the upper 3 lights on the back center of the rig. the guy took the fixtures off and the lights just fell out (little or no wiring attached). In looking at the wiring, it was the original manufacturers wiring, but very very short. We're assuming that day on the assembly line they were running short on wire or cut ours too short, wired one light, then had to "pull" it to get to the other side thus disconnecting or making the connection on the ones in the middle very shoddy. Over the past couple years and vibration they finally came off.
Problem is now fixed and we are good to go!

rockfordroo · 08-04-2016, 08:48 PM

Glad to hear. Also surprised you could get it looked at so quickly. Most people have to wait days or weeks. Did you take it to a dealer?

Broadway Joe · 08-04-2016, 08:50 PM

Glad to hear all is well, enjoy your trailer.

LisaMarie81 · 08-05-2016, 05:45 AM

Rockfordroo - we have a small mom and pop company around here that does hitches, brake systems, "toys" for trailers and campers. Not a dealer.
Small hole in the wall, but fantastic hard working knowledgeable guys working there. The kid knew exactly what he was doing and had it troubleshot and fixed within 45 minutes. We told him we'd be using them from now on! (same company that installed my electric brake)

My husband called them yesterday when they opened and he said bring it on down.

**Bama Rambler** · 08-05-2016, 07:12 AM

Thank you very much for coming back and letting us know what it was and how you got it fixed. And you learned something about electrical in the deal!

Also, thanks for letting us know about the fantastic service you got for the local shop.
I think you should post the name of the business here so that people can use them if they're in the area.

You could also write a review of them in the reviews section.

LisaMarie81 · 08-05-2016, 12:37 PM

Not a bad idea!

I'm from Western Mass and the company that helped us out is Cap and Hitch in W. Springfield. We've had 2 experiences with them and both have been fast, thorough, polite, and they've gone way out of their way.
Great Staff and lots of experience.

They will be the first people I contact going forward for any questions or issues!

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