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2017 PM2500, 159"WB
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Discussion Starter · #1 ·
I'm trying to tap into a fuse for my DC-DC charger that only comes on when the engine is running, renogy charger requires a DC+ wire.

My manual does not seem to have any diagram of the fuses, just lists of the numbers, use, and size of fuse. I have found charts online to show which socket is which number so that's fine but is there a chart somewhere in the van/manual that I'm missing?

I've read through lots of threads but no one ever seems to mention which fuse number they're tapping into, or they do it another way. I have a fuse piggy-back adapter and it seems easy enough.
 

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2018 136 HR Ont.
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Someone suggested that if you really want power only when the engine is running (instead of 'key on') you should tap into the fuel pump power wire under the floor mat. Fuel pump only gets power when the engine is running, or just about to be running.
 

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'16 2500 159 HT Granite Window - OH(io)
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Someone suggested that if you really want power only when the engine is running (instead of 'key on') you should tap into the fuel pump power wire under the floor mat. Fuel pump only gets power when the engine is running, or just about to be running.
I would be hesitant to use the power to the fuel pump directly. That being said, if you use that power to control a separately fused relay, I think that you would bed OK. You want to isolate the charger from the fuel pump.

Please forgive my crude drawing ! Rectangle Slope Font Parallel Handwriting
 

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2018 136 HR Ont.
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I would be hesitant to use the power to the fuel pump directly. That being said, if you use that power to control a separately fused relay, I think that you would bed OK. You want to isolate the charger from the fuel pump.
I don't think there would be any problem it you are just taking a few milliamps for a trigger signal. You wouldn't need a relay even if you were drawing an amp or two. The relay might draw as much as the trigger.
 

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'16 2500 159 HT Granite Window - OH(io)
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It's not the current draw that I would be concerned about, but any possible interference presented to the fuel pump module from the charger.
 

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'16 2500 159 HT Granite Window - OH(io)
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I'm trying to tap into a fuse for my DC-DC charger that only comes on when the engine is running, renogy charger requires a DC+ wire.
Back to the original question, it appears the Fuse 31 will give you what you want. (upper left fuse) Rectangle Font Screenshot Machine Display device


This picture is for a 2016, but should be accurate for most.
 

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2018 136 HR Ont.
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On the wiring diagram Fuse 31 is on the wire labeled "Ignition SW Output (Run)"
Not sure exactly what that means. Does it have power when ignition switch is simply turned on without the engine running?
 

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2017 PM2500, 159"WB
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Discussion Starter · #10 ·
On the wiring diagram Fuse 31 is on the wire labeled "Ignition SW Output (Run)"
Thanks for answering my original question, I'll probably go ahead and use that. My fuse chart in the manual refers to F31 as "INT/A", but where is the wiring diagram?
 

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'16 2500 159 HT Granite Window - OH(io)
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Not sure exactly what that means. Does it have power when ignition switch is simply turned on without the engine running?
From the looks of things from the schematic, no. I will verify tomorrow when I have access to the van.
 

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83Grumman said:

Not sure exactly what that means. Does it have power when ignition switch is simply turned on without the engine running?


From the looks of things from the schematic, no. I will verify tomorrow when I have access to the van.
I have to apologize, I was wrong about Fuse 31. It has power when the key is in the run position, whether the engine is running or not. It does not have power when the key is in the start position, however.
 

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I have to apologize, I was wrong about Fuse 31. It has power when the key is in the run position, whether the engine is running or not. It does not have power when the key is in the start position, however.
So the B2B will flick on and off during starting and attempt to charge with key on but engine not running?
That's why I think the fuel pump wire may be a good choice for an application like this.
 

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'16 2500 159 HT Granite Window - OH(io)
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So the B2B will flick on and off during starting and attempt to charge with key on but engine not running?
That's why I think the fuel pump wire may be a good choice for an application like this.
You are correct. (I still stand behind my suggestion of using a relay.)
 

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2019 Promaster 3500 Silver high top 159"
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If the upfitters connector is installed there is an "engine running" signal (Aux Run) listed here: eupfconn.pdf (ramtrucks.com) That signal must come from somewhere unless it is sniffed off the CAN bus by the upfitters connection block.

Anyone have a service manual with complete wiring diagrams? I can't find anything searching the web...
 

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If the upfitters connector is installed there is an "engine running" signal (Aux Run) listed here: eupfconn.pdf (ramtrucks.com) That signal must come from somewhere unless it is sniffed off the CAN bus by the upfitters connection block.

Anyone have a service manual with complete wiring diagrams? I can't find anything searching the web...
P820 - Aux 1 Relay Control Signal can be found on Pin 4 (brn/blk wire) of C8 which is plugged in to the back side of the BCM. Can't find any description of what it actually does. The upfitter description says it provides a ground path for a relay. I guess the thing to do would be to attach a relay and see how it reacts. Good find Larry !
 

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I was under the impression that the promaster 12 volt outlets switched on / off with the engine running, but have not double checked.

On the minivan that I had, the dealer was able to set these outlets to either stay on all of the time, or switch on / off.
 

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I was under the impression that the promaster 12 volt outlets switched on / off with the engine running, but have not double checked.

On the minivan that I had, the dealer was able to set these outlets to either stay on all of the time, or switch on / off.
The outlets are switched, but with the key in the run position, regardless of the engine running or not.
 
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