Tapping into DC power to install aftermarket fridge fan.

[Beachcamper]

I have ordered the Titan rack fan to try to see if it will help with keeping fridge and freezer temps colder. It’s been hot here in South Florida but cooled down a bit and temps are now stable. Leads me to believe cooling with additional fans would work. I have looked for instructions on how to get 12 volt power to the fans but can’t find anything. Here is where my 12v terminal block is on my DM2862. I am assuming the left is the positive and right is negative. Plan is to just unscrew from top and insert bare fan wires into each slot as marked. Will this be an issue with those wires already in there?






Thanks for any help.

Vivian

[howson]

Here is where my 12v terminal block is on my DM2862. I am assuming the left is the positive and right is negative. Plan is to just unscrew from top and insert bare fan wires into each slot as marked. Will this be an issue with those wires already in there? Thanks for any help.

According to their website, that fan and controller combination will pull a maximum of .48A, or 5.76 watts. https://www.titan-cd.com/en/product/...22-Series.html

I agree that block is where the 12v is supplied to your Dometic 2862. Indeed the left side as you've marked in your picture should be + and the right side -.



From what I see that means the circuit is fused from the Convenience Center. That means the fuse protecting the circuit is most likely 15A. (Probably the one marked "Kitchen", but not guaranteed.) What I'm getting at is a 1A fuse added first to the + side of the block, then the fan wiring, might be wise. (If one of the real electricians says differently follow their advice!) You can pick up a small fuse holder with standard fuses from any auto parts store.



Adding the fuse wire to the + side of that block should not be an issue, nor adding the - wire from the fan controller to the block.

I suggest avoiding the tap splices to join the fuse wire to the fan wire.


Best is to solder or crimp the connection, then cover with heat shrink. If you don't have these tools, another option is a push-in wire connector. GD uses these on the trailer. So far I've had good luck with them (no failures).



Good luck with the project. Look forward to reading your follow-up report.

Howard

[Beachcamper]

Howard, I do so appreciate your time to look into all this for me, I learn so much from all of you. I probably have some left over fuse holders and connectors from my last project to build a portable power box for my kayak depth finder so it’s a waterproof one. It looks from the diagram the stock fans are coming into the other side of the terminal block. Those carry a 3 amp fuse from what I interpret in the diagram.

What are the wires coming out of the block that are white/red and white where I want to shove the necked wires into?

[OurNewEra]

Howard, I do so appreciate your time to look into all this for me, I learn so much from all of you. I probably have some left over fuse holders and connectors from my last project to build a portable power box for my kayak depth finder so it’s a waterproof one. It looks from the diagram the stock fans are coming into the other side of the terminal block. Those carry a 3 amp fuse from what I interpret in the diagram.

What are the wires coming out of the block that are white/red and white where I want to shove the necked wires into?

I have the Imagine 2970RL with the fridge in the slide. My fridge did have the factory installed single fan for ventilation. I had to replace it because it was so noisy. I replaced with dual fans. I cut out my old fan which was connected to the factory thermostat installed on the coil of the fridge so it only comes on when needed at the preset temp. It made the wiring very easy as I just tied the new fans into the wiring from the old fan that was removed.

I see your 303 has the fridge in the slide which means it should already have a fan(s) installed for venting. If it does you may want to consider wiring your new fans into the existing fan. I live north of you in Central Florida. After replacing the very poor factory fan, very noisy, with two new fans the performance on my Dometic DM2882RBF1 has been great!

[howson]

What are the wires coming out of the block that are white/red and white where I want to shove the necked wires into?

I believe the wires feeding the block are tied back to the Convenience Center panel. In other words, these wires are part of the RV's wiring and provide 12vDC to the refrigerator circuits.

The positive wire coming out of the block and to the refrigerator (follow the lines on the schematic) feed the fans and the refrigerator's circuit board.

If you look closely at the schematic you'll see how the return ("ground") from the OEM fans are tied together and go back to a single connection point.

OurNewEra (Mike) has a good suggestion. If you can find that 3A fuse, tie in the new fans between the existing fuse and the old fans (or replace the old fans) and you won't need an additional fuse. (Though 3A seems like a lot for a component that will draw a max of .48A?)

Glad you found Sadie's video on Facebook--that should definitely help you with the install.

[Beachcamper]

Here is a wide shot of where those wires connect to. So I will remove the wire nuts and twist in the new fan wires and connect at that point. I don't have those type wire nuts so will have to get some next week have residential type ones. Think that is a good idea?

I believe the fan wires are on the opposite side of the terminal block. I want to leave those fans they are working well, just adding more cooling power. So the question is, do I still need the fuse.

[howson]

I will remove the wire nuts and twist in the new fan wires and connect at that point. Think that is a good idea?

I'm not a fan of wire nuts. They are used, obviously, by OEMs so YMMV.

I want to leave those fans they are working well, just adding more cooling power. So the question is, do I still need the fuse.

As long as the new fan controller power leads are connected after the existing 3A fuse (as shown on Dometic's schematic--which is assuming GD installed the fuse) I suspect your new fans will be fine. I can't see the 3A fuse in your pic?

Remember, I'm a "shadetree RV owner" at best so feel free to consult others. I won't be offended.

I know there's many qualified electrical types on this forum, so feel free to chime in everyone.

[Superduty]

[QUOTE=Beachcamper;n36456]Here is a wide shot of where those wires connect to. So I will remove the wire nuts and twist in the new fan wires and connect at that point. I don't have those type wire nuts so will have to get some next week have residential type ones. Think that is a good idea?

I believe the fan wires are on the opposite side of the terminal block. I want to leave those fans they are working well, just adding more cooling power. So the question is, do I still need the fuse.



Hi Vivian,
I did something like this on my 303. I installed two seperate fans, mounted in the bottom vent area, pointing up towards the 4 fans that came installed on the refrig., blowing accross the tubes to the refrigerator.
I used a toggle switch to turn them on/off, which I placed in the bottom vent area.
I got the 12v from a relay that runs the upper fans. (This has a in line 3 amp fuse). When the Refrigerator switch is off inside the RV, I have no power to these fans in case I forget to shut them off. (Yes, I did forget once after we got home)

So on hot days, with the sun beating on street slide, I turn the extra 2 fans on and just let them run till dusk, then I shut them off.
I found, with the extra fans running, the main fans do not run as long either.
I seen no different effects in the Refrig temp after doing this other than the main 4 fans shutting off quicker (and my new fans are so quite, so I let them run), and removing the unwanted Heat in that area.

I see you list your refrigerator as DM2862. Mine is 1350. Hum, our 5ers were built so close together also.

[Beachcamper]

Steve, I have a 2 door fridge and a small pantry to the right of it. Is yours the 4 door one?

I have looked and looked for a relay or terminal block as in the diagram. It must be up in the top vent area. The only 3 amp is in the red wire going to circuit board (black box) behind it and that goes into the 12v block. The other red wires go to the burner.

[Superduty]

Vivian,
Yes I have the 4 door. I wanted a 2 door, but when I ordered the 5er, GD said they were only installing the 4 door models in the Reflection 303.
Butsince we have the 4dr, I do like the extra capacity.

As far as the relay, might be the difference in the 2dr to the 4dr. Tomorrow when I get home from work I will snap a couple pictures and post them. This relay (if that is indeed what it is) is just inside the lower vent. It is a square, black and has a few wires hooked to it.

[Yoda]

I have the Imagine 2970RL with the fridge in the slide. My fridge did have the factory installed single fan for ventilation. I had to replace it because it was so noisy. I replaced with dual fans. I cut out my old fan which was connected to the factory thermostat installed on the coil of the fridge so it only comes on when needed at the preset temp. It made the wiring very easy as I just tied the new fans into the wiring from the old fan that was removed.

I see your 303 has the fridge in the slide which means it should already have a fan(s) installed for venting. If it does you may want to consider wiring your new fans into the existing fan. I live north of you in Central Florida. After replacing the very poor factory fan, very noisy, with two new fans the performance on my Dometic DM2882RBF1 has been great!

Mike - What fans did you use?

[Yoda]

Here is a wide shot of where those wires connect to. So I will remove the wire nuts and twist in the new fan wires and connect at that point. I don't have those type wire nuts so will have to get some next week have residential type ones. Think that is a good idea?

I believe the fan wires are on the opposite side of the terminal block. I want to leave those fans they are working well, just adding more cooling power. So the question is, do I still need the fuse.

From the picture they look like they are not wire nuts, but bulb crimp connectors. I have never found a wire nut on my unit - everything is the bulb crimp connectors which need to be cut off. Be sure the circuit is dead before doing things too. Its easy to short a 12V line - then you have to find where the fuse is

[Beachcamper]

From the picture they look like they are not wire nuts, but bulb crimp connectors. I have never found a wire nut on my unit - everything is the bulb crimp connectors which need to be cut off. Be sure the circuit is dead before doing things too. Its easy to short a 12V line - then you have to find where the fuse is

Yep after looking at it more and not finding any other place to tap into, just going to loosen the screws from 12v block, slip the wires into each corresponding side and tighten things up. Will turn battery and power off and remove negative cable from battery.

[OurNewEra]

Mike - What fans did you use?

I ordered these off e-bay

https://www.ebay.com/itm/2-RV-Boat-R...YAAOSwNmhes2PC

Great service! They shipped out of Georgia and arrived in two days.

Here is the thread I posted to previously on this topic.

https://gdrvowners.com/forum/operati...frigerator-fan

These fans did just fit between the back of my fridge and the back wall. So be sure you have the clearance between the back of fridge and back wall of slide.