Transit Connect (2016) Renogy DC DC Charger Install

[gkb2016]

Recently I installed a Renogy 20 amp DC-DC Charger in my van. It's working great, but figuring out the logistics was a pain ... so I'll save you the time! First off, I followed the Renogy wiring diagram shown in the instructions.

Under the dashboard to the left of the brake pedal, there is a small plastic/rubber grommet hidden behind some carpeting. If you pull that out, you can fish your positive, negative, and D+ wire through to the engine bay. It will come out to the right side of your battery box.

Inside your fuse box, you can use a fuse tap to piggy back off fuse F42 (rear window wiper) for the D+ signal. This fuse only comes on when the ignition is in the on position. Figuring this part out was probably the most time consuming part.

Works great and is really helping keep my batteries topped up ... whereas before I was going below 50% every day.

 

[frater secessus]

Useful info for TC folks, thanks for sharing.

you can fish your positive, negative, and D+ wire through to the engine bay

Does this mean you ran a separate negative to the batt/alt? If so, what factors went into the separate wire rather than using the chassis as a negative return?

 

[gkb2016]

Yes to the battery. IIRC that is how the manual says to wire it - I have no idea what I'm doing when it comes to grounding so I just followed the manual.

edit: Page 9 of the manual states ...
"The DC-DC share a common negative ground meaning that there should be only one common ground point between all batteries and electronics typically seen in either chassis/body ground, a canopy, a trailer, or even the vehicle battery negative connection. In most cases, connecting the starter and house battery directly to the DC-DC is enough for a grounding application. You will not ground the body of the DC-DC. "

 

[gkb2016]

Soooo one side of my 30a Renogy ANL fuse melted and this is no longer working (I’m sure that’s a good thing )

The only problem is I don’t know why / what to do next.

The manual did call for a “25A or close” fuse, closest I could find was 30A.

Only other thing I can think of is maybe some water got on it from a leak in my roof? Doubtful though.

 

[user 423]

^Which side? Input or output?

 

[gkb2016]

^Which side? Input or output?

Input. It was the positive cable connected to the starter battery. The fuse melted only on one side - the side connected to the starter battery. On the other side of the fuse (connected to dc dc charger) everything looks like it wasn’t effected.

Manual actually calls for 30a fuse on that side, which is what I used for both sides since I couldn’t find a 25a fuse for the output side and I think a 20a fuse is too small.

I am thinking of taking this opportunity to upgrade to the 40a or 60a charger because I’ve found the 20a can’t keep up with my electrical needs on heavy usage days. Lately I have been needing to run some energy intensive simulations on 2 of my computers and it’s draining a lot of juice.

Edit: attached wiring diagram photo pointing to the melted area

 

[user 423]

How was the wire protected where it went thru the firewall? Did you use a grommet?

 

[gkb2016]

Didn’t use any protection , just ran it through a hole (factory, not sharp or anything afaik). Cable looks to be in good shape.

 

[abnorm]

Was the connection LOOSE..................Half a melted fuse indicates a local heat source.

 

[gkb2016]

Was the connection LOOSE..................Half a melted fuse indicates a local heat source.

There is a potential this could be the cause. I actually had the wire pull out of the ring connector when installing and had to recrimp it.

For what it’s worth, everything seemed to be going fine with this setup til today (or yesterday at the earliest). I was running it for an extended period of time, like 6+ hours a day, which is not something I usually do.

 

[gkb2016]

Decided on keeping the 20a charger instead of upgrading. I will be upgrading the wiring though to 4 AWG and a new fuse of course.

I think I might have used wiring that was not heavy enough gauge for the run length, got confused when reading the manual, but 4 awg looks to be good for their worst case scenario (30 ft wire run). Probably another factor in this situation and lucky that I didn’t turn my van in to a crisp.

 

[user 423]

Decided on keeping the 20a charger instead of upgrading. I will be upgrading the wiring though to 4 AWG and a new fuse of course.

I think I might have used wiring that was not heavy enough gauge for the run length, got confused when reading the manual, but 4 awg looks to be good for their worst case scenario (30 ft wire run). Probably another factor in this situation and lucky that I didn’t turn my van in to a crisp.

I meant to ask you what size wire you used. I have the same charger and have 8AWG to go just 8' and that's a size up from what they recommend. There's a current limiting feature that's mention also but I'm not sure why you would want to put a 50% limit on current.

 

[gkb2016]

I meant to ask you what size wire you used. I have the same charger and have 8AWG to go just 8' and that's a size up from what they recommend. There's a current limiting feature that's mention also but I'm not sure why you would want to put a 50% limit on current.

I believe that I used the smallest wire they recommended (10-12 awg IIRC) but each cable was 10-12 ft long ... so I think that should be 4 AWG since the total wire run would be 20-24 feet. Yeah, the only way I could see someone wanting to use the current limiting feature would be if they got the 60a charger and the 40a charger is too much power... although I guess there is a case for using it on the 20a charger as well. (Renogy sells 20a 40a and 60a chargers)

 

[sithigh]

The only way I think a 25 A fuse would blow before a 20A charger is you made a bad crimp that heated up. Please fix the bad connections and use gromets before you drive it far.

 

[sithigh]

The only way I think a 25 A fuse would blow before a 20A charger is you made a bad crimp that heated up. Please fix the bad connections and use gromets before you drive it far.

Oh, and fused systems work to prevent fires. Other rigs were not so lucky. Maybe they had improper terminations too.

 

[gkb2016]

What is the purpose of the grommets? Genuinely don’t know.

Edit: from what I found on Google it’s to eliminate sharp edges that might cut through the rubber on the wire

 

[tx2sturgis]

The grommets protect the wire insulation covering from being cut or worn by a sharp metal edge. Vibration and movement can wear right thru the insulation (given enough time) even if the metal edge is painted and feels smooth to the touch. If that happens, the result is usually a 'short'.... and either a simple blown fuse or a smoking pile of metal and plastic.

As mentioned by abnorm, if only one end of a fuse is melted, scorched, etc, then that indicates a bad crimp or loose fastener. The connection warms up, oxidizes, gets warmer, then oxidizes more, thermal runaway and then...either it melts and fails or it catches something on fire nearby.

You got lucky there.

You should be absolutely sure the new replacement fuse, fuse holder, and connections (crimps etc) are correctly made, tight and secure.

 

[gkb2016]

The grommets protect the wire insulation covering from being cut or worn by a sharp metal edge. Vibration and movement can wear right thru the insulation (given enough time) even if the metal edge is painted and feels smooth to the touch. If that happens, the result is usually a 'short'.... and either a simple blown fuse or a smoking pile of metal and plastic.

As mentioned by abnorm, if only one end of a fuse is melted, scorched, etc, then that indicates a bad crimp or loose fastener. The connection warms up, oxidizes, gets warmer, then oxidizes more, thermal runaway and then...either it melts and fails or it catches something on fire nearby.

You got lucky there.

You should be absolutely sure the new replacement fuse, fuse holder, and connections (crimps etc) are correctly made, tight and secure.

I take it that a good practice would probably be to check for oxidation on the fuse on a fairly regular basis?

 

[abnorm]

MELTING is not the normal failure of an ANL fuse.....That bolt and nut had to be glowing Red to melt the fuse !

 

[tx2sturgis]

Yep. Not good if the thing got super heated.

As far as checking for oxidation. If you live or camp in humid areas, rainy forests, along the beach, anywhere the humidity is high, I would recommend that you use a knife (or small metal bristle brush) and scrape the metal parts where they mate, till they are shiny metal, then use some de-oxit or simple 'bulb grease' on the connections after scraping them, and then make sure the connections are tight.