Jensen stereo short circuit, installing fuse blows fuse in panel

photon

Some time ago, as we were not using the stereo, we got tired of the light from it at night so pulled the fuse. When getting it ready to sell, I reinstalled the fuse and it blew fuse 3 in the panel (lighting, radio, TV) right away. I thought it might have been a weak fuse so replaced the panel fuse and it blew again immediately. I'm guessing I have a short circuit but don't know where to start to troubleshoot it. This is a Jensen AWM965 in a 2014 T@B.

Although there are places for up to 20 wires in the connector on the back of the stereo, only 6 are connected to the trailer. The others are cut off at 6-8 inches mainly for additional speakers according to the wiring chart. This is what is connected:

15 YELLOW MEMORY/BATTERY (+) (this wire is in fact red not yellow)

16 BLACK GROUND

17 VIOLET RIGHT REAR (A) SPEAKER (+)

18 VIOLET/ BLACK RIGHT REAR (A) SPEAKER (-)

19 GREEN/ BLACK LEFT REAR (A) SPEAKER (-)

20 GREEN LEFT REAR (A) SPEAKER (+)

The only odd thing, noted above, is that the wire at 15 is red not yellow.

Additionally, loose in the space behind the stereo are two wires, both with tinned ends. One is red and labelled +12VDC and the other is red and black and labelled GND. I'm sure they weren't touching anything else when I inserted the fuses. I intend to put electrical tape on them unless I find they need to be connected somewhere.

I might also mention that the 12V battery is removed, the trailer is connected to my household 120V with a heavy duty extension cord.

I'm not knowledgeable about electronics so don't know where to start to troubleshoot this so any comments or suggestions would be most welcome.

pthomas745

What year trailer? Look over this thread, which discusses wiring a "on off" switch for the Jensen.

And, somewhere buried in your Jensen manual, there are instructions for either turning off or dimming the lights.

Look over this thread:

https://tab-rv.vanillacommunity.com/discussion/5577/jensen-radio-disconnect/p1

photon

It's a 2014 T@B. Thanks for the reference but the Jensen doesn't operate due to the fuse blowing as mentioned in the first paragraph.

pthomas745

What I was thinking is if the Jensen has been disconnected and the bare wires are shorting out, that may be the source of your fuses blowing.

gulfarea

What amp is the fuse that is blowing and i it a slow blow type fuse? Art

Yoshi_TAB

Hi,  Most likely it's a loose or  cut wire.  Its going to take some detective work to find it.    I would suggest, if you have not already, focus at first on a close inspection of the #15 and #16 wires and look for chaffing and  any cuts along the entire circuit from the Jenson to the WFCO (#3).    Follow the circuit (#15 and #16 wires) as much as you can.  Look behind the WFCO where the Jenson wires tie  into the #3 fuse.  That could be where the issue is.   If possible you may have to remove some other items to get to the the wiring.  Here is a technique I've used. RVelectricity: Finding short circuits in 12-volt systems, Part 2A - RV Travel  Good luck.

(the other red wire is probably the #8 and would not be used.  But good idea to cap it off.  )

photon

gulfarea said:

What amp is the fuse that is blowing and i it a slow blow type fuse? Art

It's a 10A blade-type automotive fuse, same as the one that is blowing in the main panel. They are not slow-blow designs.

photon

Yoshi_TAB said:

Hi,  Most likely it's a loose or  cut wire.  Its going to take some detective work to find it.    I would suggest, if you have not already, focus at first on a close inspection of the #15 and #16 wires and look for chaffing and  any cuts along the entire circuit from the Jenson to the WFCO (#3).    Follow the circuit (#15 and #16 wires) as much as you can.  Look behind the WFCO where the Jenson wires tie  into the #3 fuse.  That could be where the issue is.   If possible you may have to remove some other items to get to the the wiring.  Here is a technique I've used. RVelectricity: Finding short circuits in 12-volt systems, Part 2A - RV Travel  Good luck.

(the other red wire is probably the #8 and would not be used.  But good idea to cap it off.  )

Thank you. That gives me a good starting point.

photon

pthomas745 said:

What I was thinking is if the Jensen has been disconnected and the bare wires are shorting out, that may be the source of your fuses blowing.

The two bare wires in the cabinet were not touching at any time when testing and blowing fuses. The Jensen is connected with a multi-pin connector as seen in the earlier picture and there are no 'disconnected' wires on their own. The two bare ones are not part of the wiring harness.

SLJ

First, pull the multi-pin connector out and plug in a new fuse. If it blows it's in the wiring. If it doesn't, plug the connector back into the Jensen. If it blows, it's most likely the Jensen if there's been no wiring changes.

photon

SLJ said:

First, pull the multi-pin connector out and plug in a new fuse. If it blows it's in the wiring. If it doesn't, plug the connector back into the Jensen. If it blows, it's most likely the Jensen if there's been no wiring changes.

I put new fuses in the main panel and the Jensen then plugged in the connector to the Jensen. It immediately blows the main panel #3 fuse (10A) but not the fuse in the Jensen. The odd thing is there've been no wiring changes and the Jensen has just been sitting there without power (fuse pulled in Jensen) for the past few years. The main panel fuse has never blown previously.