Cooltech and RVI charger...be aware

[Redbaron73]

I recently installed the cooltech flat tow harness and the rvi towed battery charger.

After the install I noticed that some of my circuits remained active when the battery was disconnected *and* the 3 lugs on the sidewall where disconnected.

I traced the problem to the installation of the cooltech combined with battery charger.

When the cooltech is installed, the ground from the 6 way plug is also connected to the chassis. This is under the passenger footwell. See this picture:

Now when the rvi tbc is installed, the ground from the RV side is joined with the ground of the cooltech.

Internally, the rvi grounds are common, so if you connect the rvi to the battery directly, then it will remain joined with the 2nd battery, and via the cooltech harness provide a ground path.

This could be a real problem, as it is a very small gauge wire and too much load will cause damage.

For safety, I have relocated my vehicle side ground of the rvi to the sidewall posts.

If you leave it connected to the battery, this should be the first connection removed, and the last to be installed.

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[Jmonroe]

I'm not understanding why there is a problem.

My Cooltech wire harness is grounded to the post behind the passenger kick panel, as shown. I simply connected the toad charger directly to the battery terminals. As the entire vehicle is, essentially, grounded through the body & frame, how would simply moving the ground connection fix anything, if there was a problem?

 

[Redbaron73]

When connecting the rvi charger to the ground, the most like likely connection one would make is under one of the 2 nuts circled here:

When doing the disconnect, the normal method is to remove the battery ground, and the 2 sidewall grounds.

This is the danger, as the circuit is still connecting via the rvi charger and the cooltech harness.

This connection path is from the rv side of the charger where the cooltech ground and the rvi ground are joined before going to the 6 way plug.

You *must* remove the rvi ground from the battery post before removing any other ground, since this is a small 16awg wire. It will overheat and cause damage to itself or other components if disconnected incorrectly.

I find it much safer and easier to connect the rvi ground to the sidewall lug, and have it disconnect before the 2/0awg ground.

 

[Jmonroe]

Still not sure I'm following this but I do understand the concept of a common ground. Every electrical component in the vehicle shares a common ground, they just don't tap into it at the same place. Are you suggesting you should not use the toad charger if you are using the Cooltech harness at all?

A single toad charger line goes to the "battery" or power post in the 6 pin connector. The only ground connection comes out of the charger unit itself directly to the battery so I'm still not understanding how it creates any potential issues with the Cooltech toad harness and if so, why not with the unaltered vehicle harness?

Call me dense if you will, but I'm still not getting it.

 

[Redbaron73]

Still not sure I'm following this but I do understand the concept of a common ground. Every electrical component in the vehicle shares a common ground, they just don't tap into it at the same place. Are you suggesting you should not use the toad charger if you are using the Cooltech harness at all?

Absolutely not suggesting this -- the toad charger and cooltech are a great combination.

A single toad charger line goes to the "battery" or power post in the 6 pin connector. The only ground connection comes out of the charger unit itself directly to the battery so I'm still not understanding how it creates any potential issues with the Cooltech toad harness and if so, why not with the unaltered vehicle harness?

Call me dense if you will, but I'm still not getting it.

When you connect the cooltech ground to the frame, this wire extends to the 6 way plug. With the RVI Charger, you are connecting the "RV SIDE" of the ground wire to the same harness. See this picture from figure 7, Step 10:

I added the red wire drawing indicating the RVI wire.

Now what happens is this wire from the "RV" side of the RVI is internally connected to the "Vehicle" side of the of the RVI cable, which is in turn connected to the ground.


The JL wrangler has 2 batteries. One you see, and one below it.

When you remove the ground wire from the upper battery by using the single 10mm lug and removing the cable, you still have a ground path to the other battery.

To properly disconnect the vehicle from all ground sources, you are supposed to also remove the cables on the sidewall.

This is where the problem is with connecting the RVI Jeep side to the battery terminal. With the battery charger ground on the battery terminal, it is still connected to the 2nd battery. The cooltech harness is now completing a path to the chassis (See Step 5 + Figure 7 Step 10 ).

The vehicle is still finding a ground and power source, and will overload these wires.

I discovered this only after doing my normal disconnects, and noticing the interior lights remained on.


The solution is very simple. Do NOT connect the RVI Battery Charger directly to the battery. Instead, connect it to the sidewall, where it will be removed as part of your normal disconnect procedure.

This will allow the battery charger to work as intended, and remain safe when the battery is being disconnected.

I should stress that it is not good enough to say, "I know it needs to be disconnected and will do so", as the dealership or anyone else working on it will not know this. If they only remove the battery ground, the vehicle remains charged, but there is a sufficiently large (2/0 awg) wire that is in place to handle the load on the sidewall. If they know enough to remove this wire, then they will end up removing your wire as part of the process, thus keeping it safe.

 

[Jmonroe]

OK, your concern is the installation.

I didn't have to touch the connection to the negative battery post, I was able to use one of the ancillary posts coming off the side of that main connection.

So, when it comes time to replace the battery...

 

[Redbaron73]

OK, your concern is the installation.

I didn't have to touch the connection to the negative battery post, I was able to use one of the ancillary posts coming off the side of that main connection.

So, when it comes time to replace the battery...

Then you did it the proper way. This is what I was documenting to make sure others are aware.

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