12V from TV not powering refer.

06-20-2008, 09:24 PM

It seems that the TV (7 wire, factory installed Toyota Tacoma V6) isn't powering the refer. Works fine on shore power, gas. Battery charges from shore power with no problems.

Now I haven't performed a full test. My plan is to pull the fuse on the TM battery and see if the interior lights work when connected to the TV. I suspect that they will not.

Anybody got ideas on what might be wrong.

**ShrimpBurrito** · 06-20-2008, 11:31 PM

There's a good chance there is not adequate voltage at the TM battery terminals while the TV is running. I have a factory installed tow package on a Toyota Sequoia, and there is a significant voltage drop between the alternator and the TM battery terminals. Several folks have reported this as an issue, and some have resolved it by installing larger wire. Since copper is so expensive these days, that's not a cheap option, and even then, while it will run the fridge and charge the batteries, it won't charge the batteries all the way. I still haven't come up with a solution that is relatively inexpensive (less than $400).

You'd probably want to take a look at this thread:
http://www.trailmanorowners.com/foru...ead.php?t=3822

Dave

**wbmiller3** · 06-21-2008, 06:37 AM

I wasn't sure if you got no 12v from the TV or just no cooling on the fridge when towing. You can check the voltage at the connector if you suspect no 12v from the TV by getting a wiring diagram for the Bargman connector. They are not hard to turn up on the internet if you don't have one. Here is a verbal description of the way mine is wired. If you look into the vehicle side of the connector with the "key" at the top, reading clockwise from the one o'clock position the pins are battery charge, right stop/turn, brakes, common ground, left stop/turn, and running lights. Looking into the trailer connector with the key at the top and reading clockwise from the one o'clock position the sockets are running lights, left stop/turn, common ground, brakes, right stop/turn, battery charge. The central pin is "center auxiliary"? but should not be a player in this problem. But find a picture and check for yourself!!

Just connect a voltmeter across the battery charge and common ground pins and see if you have 12v. If you do, it's probably an inadequate amps problem which has been discussed often on the forum.

**commodor47** · 06-21-2008, 10:14 AM

Quote:

Originally Posted by ng2951

It seems that the TV (7 wire, factory installed Toyota Tacoma V6) isn't powering the refer. Works fine on shore power, gas. Battery charges from shore power with no problems.

Now I haven't performed a full test. My plan is to pull the fuse on the TM battery and see if the interior lights work when connected to the TV. I suspect that they will not.

Anybody got ideas on what might be wrong.

Have you checked the two fuses located near the bottom of the refrigerator? They can be accessed from the lower louvered outside vent. One fuse is labeled 20 amp and the other tag says 3 amp. I believe the 3 amp fuse is used to power the refrigerator off the 12 volt circuit.

http://good-times.webshots.com/photo...95282683bhPVXu

Dick

**ShrimpBurrito** · 06-21-2008, 10:20 AM

The fridge takes 10 amps on 12 volts, so it presumably wouldn't be the 3 amp fuse.

So you could have a multitude of possible problems:

- inadequate voltage in the TM from the TV power lead
- blown fuse at the fridge
- blown fuse in the TV for the towing charge circuit
- burnt 12 volt heater element in the fridge
- loose/broken connection somewhere between the TV alternator and the fridge

Should make for a nice afternoon.

Dave

06-21-2008, 12:36 PM

Well I opened the battery in the TM and connected the cable to the TV. Brake controller shows connected, nothing works in the TM. That, on the surface says no 12 V from TV.

So I will check the the fuse in the TV and power on the connector.

06-21-2008, 01:37 PM

New info.

On the Tacoma, the TM is NOT power unless the ignition is on.
With the TM battery opened (fuse removed) I turned on some lights to test the Tacoma trailer charging circuits. Initially, with the ignition off, there were no lights. After checking the TV's fuses I saw that the fuses were good.

I turned on the iginition and then the lights in the TM lit.

I checked the fuses on the refer, and they too are intact and I have 12 volts on the strip on the back of the refer.

Next is to test the refer and see if it will cool on 12 volts (lined up on shore power).

So here is what I know:

On TV power--

At end of a long day refer is warm when lined up on DC power.
TM battery is dead.

On shore power--

Refer runs fine on A/C or DC
Battery charges
All DC circuits work.
When refer turned on DC converter fan spins up.

I find it difficult to believe that I have multiple problems in the DC circuit. I can also understand how the battery might not charge due to the length of the power cable from the TV.

However, unless there is something really strange about how the converter box works, I do not understand why the refer won't cool on DC.

06-21-2008, 02:52 PM

I have the TV isolator on my vehicle also.....which is a good thing in my opinion. But if you stop for a long period of time, the fridge keeps on running off of the batteries, which could pull you batteries down and not power the fridge after a time. If I kill the engine for longer than a pit stop, then I will pull the fuse and put it on my driver's seat so I don't forget to replace it before I drive off....meaning no more fridge, charging the battery, or emergency disconnect braking system.

Just a thought if you have long rest stops, especially right before you set up for the nite.

Chap

**commodor47** · 06-21-2008, 05:54 PM

Quote:

Originally Posted by commodor47

Have you checked the two fuses located near the bottom of the refrigerator? They can be accessed from the lower louvered outside vent. One fuse is labeled 20 amp and the other tag says 3 amp. I believe the 3 amp fuse is used to power the refrigerator off the 12 volt circuit.

Dick

Need to correct my previous post: the 20 amp fuse is for the DC side (of the refrigerator) and the 3 amp fuse is for the AC.

Reference this thread, post #12:

http://www.trailmanorowners.com/foru...or+fuse&page=2

Dick

**ShrimpBurrito** · 06-21-2008, 06:23 PM

So based on your tests, I'd say you've narrowed down the problem to either:

1) a burnt DC heater element in the fridge; or
2) inadequate voltage at the TM from the TV

If the fridge works on DC while the TM is plugged into AC, that would seem to point to option 2 as the culprit. Since you said the TM battery is dead upon arrival at camp, that's another vote for option 2. If the heater element was fried, it wouldn't draw any power, and your TM battery would be fine when you arrived.

What I would do is first start your TV and let it idle for 20 minutes. You need to do this because your alternator output will decrease as it gets warm, and you need to know the operating output voltage. Then, turn off everything in the TM, and disconnect the TM battery leads (or just one, or whatever). Take a voltage reading at your TV battery terminals while the TV is running, and then while the TV is still running, measure the voltage output at the TM battery leads. In my case, my TV voltage was ~13.9v, and the TM battery lead voltage was ~12.5 volts. Based on my actual experience, and from ammeter readings (the Link 10), that is insufficient voltage to power the fridge & fridge fan. I have about a 2 amp draw off the TM battery most of the time while the TV is running.

If you look at the wiring diagram in the blue binder, you will see that the TV charging lead goes right to the TM battery. There are no circuits, chargers, or anything, and the converter does nothing while towing.

Dave