Comprehensive 5th-Gen 1500 Fuse / Relay / Circuit Breaker Documentation

[HAL9001]

I posted a diagram for the Internal Fuse Panel recently. This was good information to share with other 5th-Gen 1500 owners because the owner's manual doesn't contain such a diagram and the labels on the panel are very hard to read.

However, there was a lot more information that could be even more useful such as a diagram for the External (Engine Compartment) fuse panel as well as better detailed information about all of the fuses, relays, and circuit breakers. This took a while to compile but it was worth it because it will be a handy reference for anyone who could use it.

I created the information in a spreadsheet database and then published it on the internet. From here anyone can reference it any time online. I've also created two pdf document files if you wish to download the information directly to your computer or your smartphone. You can print a hard copy or keep it on your smartphone to access it easily if you ever encounter any issues on the road.

The website and the files both contain detailed information about both the Internal and External Power Distribution Centers, much more than the owner's manual or any other such documentation I could find. For example, you can now very easily find all fuse and relay locations and reference with expanded detail what each one does. Instead of using the esoteric acronyms used in the owner's manual to describe the fuses and relays, I've expanded most of them to their full names. This makes it much easier to understand what each one does.

Please see for yourself. Here is the RAM 1500 5th-Gen Power Distribution Centers website. Also, I've attached the pdf files for both the Internal and External Power Distribution Centers to this post. Simply download them to your computer and/or smartphone. From there you can print out a hard copy if you wish.

Here is a screenshot example of the partial Fuse Description table:



Here are the included Fuse Panel Diagrams:

External Fuse Panel:



Internal Fuse Panel:



The pdf files are attached below. One is for the Internal Fuse Panel, the other is for the External Panel.

I hope you find this information useful.

 

[HAL9001]

RAM Fuse Types:

Expanding on the information above, it's important to note that RAM used four types of fuses in both fuse panels. I carefully documented in the tables which type of fuse is used where. RAM included some spare fuses in the External Fuse Panel, which are shown in the diagrams, but none for the Internal Fuse Panel.

If you want to carry spare fuses, you may wish to buy all four types. The differences in the various types can be esoteric, I'll provide an explanation below so that you won't need to spend time researching them for yourself.

Micro2 Fuse:



These are used in both the Internal and External Fuse Panels. They may look a bit like other blade-type automotive fuses, but due to their physical dimensions, they are incompatible. These are fast-blow fuses used for quick protection. Micro2 fuses have a current rating range of 5 to 30 Amperes and are 9.1mm wide, 15.3mm tall, and 3.8mm thick.

Micro3 Fuse:



Micro3 fuses are basically a double Micro2 fuse. They are easily identified because they are longer and have three prongs. These are used only in the Internal Fuse Panel. They're available in current ratings of 5 to 15 Amperes. The dimensions of the Micro 3 Fuse are 14.4mm wide, 181mm tall and 4.2mm thick.

The Micro 3 Fuse is designed to protect 2 different output circuits from a single power source. Power flows into the fuse via the middle prong and out via the 2 outside prongs. The fuse ampere rating applies to both output circuits.

RAM also used some Micro3 fuse sockets to give owners a choice of circuits. For example, Fuse 54 is a Micro2 style fuse plugged into a Micro3 socket. The "A" side (to the left) is used for constant power whereas the "B" side (to the right) is used for IGN power. This is why there is a Fuse 54A and 54B, although you can only select one side or the other. I don't know if this is a common usage of Micro3 sockets with Micro2 fuses or if RAM is being clever.

MCASE (Unslotted-style) fuse:



MCASE are cartridge-type fuses designed to withstand inrush currents via a time-delayed action. They have a miniaturized footprint for optimal performance in minimal space. They're available in current ratings of 5 to 40 Amperes. These are used only in the External Fuse Panel.

MCASE+ (Slotted-style) fuse:



This is a rather difficult to find fuse manufactured primarily by Littelfuse. They are a newer slotted-style of MCASE fuse that can handle more current than standard, unslotted MCASE fuses. They're available in current ratings of 15 to 60 Amperes. These are used in both the External and Internal Fuse Panels. The Internal Panel uses no standard MCASE fuses, only MCASE+ slotted, whereas the External Fuse Panel uses both MCASE unslotted and MCASE+ slotted. I'm sure RAM must have has its reasons, but they sure made it difficult for owners to keep track of this.

MCASE+ appears to be a trademark of Littelfuse for their specific line of MCASE style fuses. Littelfuse also makes unslotted MCASE+ fuses that are compatible with standard MCASE fuses. Additionally, standard MCASE unslotted fuses might fit in an MCASE+ socket, and vice versa, but be aware that there may be different ambient temperature and time delay characteristics, so I would not recommend swapping them unless in a pinch. I know this is confusing, but that's just the way it is. Again, I've carefully labeled exactly where each type of fuse is located.

Well, that's probably more pedantic information you ever wanted about RAM's fuses, but again, I hope this information is useful. It helped me. Without it, things would be much more confusing. If a fuse blows on the road, you want to be able to fix it fast, but all of the confusion about these fuses may have gotten in your way.

 

[HAL9001]

Spare Fuses:

Since RAM uses so many different types of fuses, it's difficult and costly to purchase spares for the road. The biggest problem is finding MCASE+ slotted fuses because these are rare.

With some searching, I was able to find a selection of fuses for each category that can be purchased for spares.

MCASE Unslotted and MCASE+ slotted:
These were the hardest to find, especially the MCASE+ slotted, but this handy kit contains both:




Micro2:
These aren't as difficult to find. This kit contains enough of a selection to cover the RAM's needs plus you get three taps as a bonus which will come in handy if you ever install add-on accessories.




Micro3:
These are a bit hard to find but this kit has all that you'll need:




Also, keep in mind that RAM includes some spare fuses in the External Fuse Panel. I'm not sure if these are the same for all 1500s, but here is a list of the spares that came with my truck:

Micro2:

• 5 Amp
• 10 Amp
• 20 Amp
• 25 Amp

Micro3:

• None

MCASE Unslotted:

• 20 Amp
• 30 Amp

MCASE+ Slotted:

• 40 Amp
• 50 Amp

While this is a decent selection, it does not cover all of the fuses in the RAM 1500. Missing are:

Micro2:

• 15 Amp
• 25 Amp

Micro3:

• 10 Amp
• 15 Amp

MCASE+ Slotted:

• 20 Amp
• 25 Amp
• 30 Amp

If you want to save money purchasing spare fuses, then just concentrate on these.


Here is a complete listing of all the fuses (1500 Limited, your model may vary but it will be close):

Internal Fuse Panel:

Micro2:

• 5 Amp x2
• 10 Amp x8
• 15 Amp x5
• 20 Amp x9
• 25 Amp x1

Micro3:

• 10 Amp x3
• 15 Amp x1

MCASE+ Slotted:

• 20 Amp x3
• 25 Amp x1
• 30 Amp x7
• 40 Amp x4

External Fuse Panel:

Micro2:

• 5 Amp x2
• 10 Amp x9
• 15 Amp x6
• 20 Amp x8
• 25 Amp x2

MCASE Unslotted:

• 20 Amp x6
• 25 Amp x2
• 30 Amp x6

MCASE+ Slotted:

• 40 Amp x2
• 50 Amp x2

 

[HAL9001]

Note: I've recently updated the RAM 1500 5th-Gen Power Distribution Centers website and the pdf attachments in this thread with additional new information. As I learn more about the RAM's electrical systems, I'll keep both updated to supply the best information possible on this topic.

 

[HAL9001]

Note: I've updated the RAM 1500 5th-Gen Power Distribution Centers website and the pdf attachments in this thread yet again. In addition to expanding the fuse descriptions from their esoteric acronyms to their full meaning, they now also include web links to help explain the function of the components that each fuse protects. This helped me a lot and I hope it can help others too. Simply click on the fuse description and it will link to a website with the component's full description.


I found the meaning and description links for almost all of the fuses, but I could use some help with the few that remain undefined. If anyone knows the meaning of the following and a descriptive web link, please let me know:


Supply / Purging Pump

Bank 3 Switch

SW Window

Rear Coolant Temp

Wake Up


I'm also looking for a description of the circuits that Circuit Breaker # 1-4 protect.

 

[funtruck92]

Thank you for putting in the effort to make such a comprehensive list and diagram. I'm wondering if you could tell me which fuse is the remote start fuse? I see the one that says starter (F40) on the external, is that for the remote start? I looked in the manual and it appears to be labeled the same. Thanks for any help you might be able to offer.

 

[Dodge 1500 4X4]

Thank also it was very nice of you to go to the trouble, now I know what fuses and types to look for.

 

[LouM]

Nice job and thanks for all the info.

 

[DaveSharp]

I posted a diagram for the Internal Fuse Panel recently. This was good information to share with other 5th-Gen 1500 owners because the owner's manual doesn't contain such a diagram and the labels on the panel are very hard to read.

However, there was a lot more information that could be even more useful such as a diagram for the External (Engine Compartment) fuse panel as well as better detailed information about all of the fuses, relays, and circuit breakers. This took a while to compile but it was worth it because it will be a handy reference for anyone who could use it.

I created the information in a spreadsheet database and then published it on the internet. From here anyone can reference it any time online. I've also created two pdf document files if you wish to download the information directly to your computer or your smartphone. You can print a hard copy or keep it on your smartphone to access it easily if you ever encounter any issues on the road.

The website and the files both contain detailed information about both the Internal and External Power Distribution Centers, much more than the owner's manual or any other such documentation I could find. For example, you can now very easily find all fuse and relay locations and reference with expanded detail what each one does. Instead of using the esoteric acronyms used in the owner's manual to describe the fuses and relays, I've expanded most of them to their full names. This makes it much easier to understand what each one does.

Please see for yourself. Here is the RAM 1500 5th-Gen Power Distribution Centers website. Also, I've attached the pdf files for both the Internal and External Power Distribution Centers to this post. Simply download them to your computer and/or smartphone. From there you can print out a hard copy if you wish.

Here is a screenshot example of the partial Fuse Description table:

View attachment 238309

Here are the included Fuse Panel Diagrams:

External Fuse Panel:

View attachment 238312

Internal Fuse Panel:

View attachment 238313

The pdf files are attached below. One is for the Internal Fuse Panel, the other is for the External Panel.

I hope you find this information useful.

Really nice work!

 

[HAL9001]

Thank you for putting in the effort to make such a comprehensive list and diagram. I'm wondering if you could tell me which fuse is the remote start fuse? I see the one that says starter (F40) on the external, is that for the remote start? I looked in the manual and it appears to be labeled the same. Thanks for any help you might be able to offer.

I don't think there is a remote start fuse per se. There is a fuse for the starter and there would be a fuse for the electronic module which receives the radio command from the remote to initiate a remote start. But I don't think there is a specific fuse exclusively for the remote start function.

 

[Anthony Bulger]

Does anybody know which fuse and relay would be for the rear factory locker?

 

[gescobar30]

I posted a diagram for the Internal Fuse Panel recently. This was good information to share with other 5th-Gen 1500 owners because the owner's manual doesn't contain such a diagram and the labels on the panel are very hard to read.

However, there was a lot more information that could be even more useful such as a diagram for the External (Engine Compartment) fuse panel as well as better detailed information about all of the fuses, relays, and circuit breakers. This took a while to compile but it was worth it because it will be a handy reference for anyone who could use it.

I created the information in a spreadsheet database and then published it on the internet. From here anyone can reference it any time online. I've also created two pdf document files if you wish to download the information directly to your computer or your smartphone. You can print a hard copy or keep it on your smartphone to access it easily if you ever encounter any issues on the road.

The website and the files both contain detailed information about both the Internal and External Power Distribution Centers, much more than the owner's manual or any other such documentation I could find. For example, you can now very easily find all fuse and relay locations and reference with expanded detail what each one does. Instead of using the esoteric acronyms used in the owner's manual to describe the fuses and relays, I've expanded most of them to their full names. This makes it much easier to understand what each one does.

Please see for yourself. Here is the RAM 1500 5th-Gen Power Distribution Centers website. Also, I've attached the pdf files for both the Internal and External Power Distribution Centers to this post. Simply download them to your computer and/or smartphone. From there you can print out a hard copy if you wish.

Here is a screenshot example of the partial Fuse Description table:

View attachment 238309

Here are the included Fuse Panel Diagrams:

External Fuse Panel:

View attachment 238312

Internal Fuse Panel:

View attachment 238313

The pdf files are attached below. One is for the Internal Fuse Panel, the other is for the External Panel.

I hope you find this information useful.

Thank you for taking the time to do this. Really helpful. Can you show me which one is the accessories fuse for the exterior fuse box?

 

[HAL9001]

Thank you for taking the time to do this. Really helpful. Can you show me which one is the accessories fuse for the exterior fuse box?

I don't see an "accessory" fuse per se for the 1500 in the External Power Distribution Center. Unless your truck has an upfitter option, RAM does not encourage or specifically provide for owner-wired accessories. This you must do on your own.

If you want to wire in an accessory in the External PDC, you would need to use a fuse tap on an existing fuse such as F57 which is used for the horn. Try to pick something which is not too critical. Or you can tap into a 12 VDC terminal and wire in an external fuse.

Whatever you wire in, always ensure that it is properly fused for the wire gauge that you use. Always remember that fuses primarily protect the wiring from overheating, they do not necessarily protect the component.

 

[chris29]

Thank you for these, great research and pictures, this is super helpful. I am trying to see if the Park Sense are tied to a fuse panel.

 

[HAL9001]

Thank you for these, great research and pictures, this is super helpful. I am trying to see if the Park Sense are tied to a fuse panel.

The Park Sense function is software programming within the electronic control unit (ECU) and/or other vehicle control units. It's not likely that you'll find a fuse specifically for it.

 

[brian42]

Does anybody know which fuse and relay would be for the rear factory locker?

My Owner's Manual does not show a fuse for the e-locker.

As HAL9001 mentioned, these trucks integrate just about everything into the control modules (power, ground, switching, etc.) so you will be hard pressed to trace individual functions.

...RAM does not encourage or specifically provide for owner-wired accessories...

I agree with this on a whole for the auto industry.

Things are so complex now and require a lot to balance "the load". It doesn't take much to cause problems in new vehicles compared to the "old days" of a computer module or two and everything else was a stand-alone function. Now that everything is integrated it's almost more trouble than it's worth to add OEM items after the fact.

 

[l2azorback]

Thank you for assembling this needed information. I blew the fuse for my digital rear mirror and could not find the fuse to save my life. The fuse wasn't blown all the way, but would demonstrate continuity, but would not allow power to pass through.

 

[getdean]

Thanks for your time and work in putting this together Hal9001, very clear pictures.
Working on a 2019 Ram 1500 Laramie, lost fuse cover in front end accident and hard to find picture of fuse box to make sure all fuses are in correct location.

 

[ExpeditionRam]

Thank you for this. It was incredibly helpful!

 

[tvincent]

This is my first post I make, so forgive me if this is the wrong thread to ask this question in, but I'm trying to install LED strips in my 2021 Ram 1500 Bighorn and after looking over HAL9001's amazing diagram, I was going to choose F54B to use a fuse tap on because it only works when the truck is ACC/RUN. My question is, do I have to make sure I insert the fuse tap in the right direction? Is there power only through the middle slot, or is it just the outside slots? Sorry if my question is confusing, any clarification is helpful.