Re: [tabtrailers] Re: audible clicking sound when trickle-charging via 7 way

8:51 PM |

John, take a look through the AA_Electrical folder in the Files section to help understand the electrical system. The converter is a separate part of the electrical panel--it changes shore power (AC) to 12VDC for operating all the 12V functions in the trailer--lights, water pump, vent fan, etc.--and for charging the battery. The converter and the battery both feed the same 12V distribution buss. If you have shore power, the battery serves no purpose, because the converter provides the 12VDC. The wiring for the trailer external lights are (should be) completely separate (except for the ground) from the 12V power system for the internal functions--they are operated from the tow vehicle light circuits. In other words, even without a battery or a charge lead, all the external lights (brake, running lights, turn signals) will work. They are not involved with the trailer battery at all. My suspicion at this point is that the new battery is simply demanding too much charge current. With the battery disconnected, wait a few hours and check the voltage. It should not be down below about 12V. A fully-charged battery will be around 12.6V. See the BatteryDischargeTable in the *Electrical photo album, page 3.

Jerry J

----- Original Message -----

From: John Makar

To: tabtrailers@yahoogroups.com

Sent: Wednesday, April 20, 2011 10:59 PM

Subject: [tabtrailers] Re: audible clicking sound when trickle-charging via 7 way

Thanks. My money is on a low battery. I did the plug check last week which is when they were all good, but that was last week and things happen.

Sequence today was I was on shore power checking things, and there was definitely no click. Disconnected from shore, did the group's very good pre-drive check with the old battery on truck connection, but wasn't paying much attention when I checked the turn sigs, etc, so can't say for sure was no click. Drove to NAPA, swapped out old battery for core, and put in new. Started truck with 7-way connected, checked lights and that's when I heard the click for sure for the first time.

What is flow from 7-way to trailer? I thought everything passed through converter box including incoming DC from truck.

--- In tabtrailers@yahoogroups.com, "Jerry Jones" <jjerryj@...> wrote:
>
> John, a couple of other things. My earlier reply was based on the "plus" was disconnnected, when I realize now you must have meant the "plug" was disconnected. If you have a voltmeter, check the pins on the tow vehicle connector--see photo
> "Connectors pin functions" (photo 35) in the *Electrical album. Check between the ground pin and the 12V pin--there should be no voltage there if your tow vehicle is not running. If it is there, you are missing an isolation relay, but that will not be the cause of your problem, though you should have an isolation relay. Whether the engine is running or not, make sure it is reading +12V when it is there.
>
> If the polarity is correct and the voltage is not there when the engine is not running, then you have a wiring problem in the trailer.
> Disconnect the battery ground lead and set it aside, then hook up to your tow vehicle (without being connected to shore power) and measure the voltage between the ground lead and the battery positive lead. Make sure it is the right polarity. If not, you have a wiring reversal in your trailer. If it is the right polarity, then you have either a short in the battery or it is deeply discharged, causing too much current through that circuit breaker.
>
> Let me know, please.
>
> Jerry J
>
>
> ----- Original Message -----
> From: John Makar
> To: tabtrailers@yahoogroups.com
> Sent: Wednesday, April 20, 2011 8:06 PM
> Subject: [tabtrailers] audible clicking sound when trickle-charging via 7 way
>
>
>
> Today I replaced my battery with a new deep cycle marine, and now when I connect the 7-way from my truck I hear a distinct clicking sound at regular intervals from the area around the relay screwed to the frame behind the battery box. This occurs whether the truck is running or not, and completely stops when the plus is disconnected.
>
> Every thing inside works just peachy, the truck has no problems, and there is no smoke yet from anywhere. I carefully checked to make sure that I had not done obvious dumb things like mixing up positive and ground. It is totally possible that the old mostly dead battery also made the clicking sound under the same conditions, but I wasn't paying attention so can't say for sure.
>
> Any suggestions?
>