New 5th-Gen 1500 Fuse / Relay / Circuit Breaker Diagrams & 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.

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


Here are the included Fuse Panel Diagrams:

External Fuse Panel:



Internal Fuse Panel:



I hope you find this information useful.

 

[drewski]

Very helpful, thank you!

 

[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.

 

[Gitter]

This awesome!

 

[securityguy]

AWESOME job @HAL9001

MODERATORS...this needs to be a sticky!

 

[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 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.

 

[CaptainCJ35]

This is superb work!

 

[HAL9001]

Note: I've updated the RAM 1500 5th-Gen Power Distribution Centers website 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 Breakers # 1-4 protect.

 

[varmintjcl]

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:

View attachment 83575

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.

View attachment 83576

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

View attachment 83577

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

This is valuable info, thank you for putting this together, nicely done.

 

[securityguy]

@SpeedyV can you sticky this thread please?

 

[Ykndoit]

If I was to wire a lighted bug shield to turn on with the marking/parking lights, which fuse should I wire it to?

thanks!

 

[SKT Customs]

Man this is so amazing, you must’ve spent a ton of time on all that! Thank you very much for posting it. I have white puddle/under glow lights that I really want to turn on every time the standard mirror puddle lights come on (I.e when you unlock or open a door, etc) and I’ve always thought I should tap into F36 (exterior light fuse) but it’s an MCASE+ fuse & idk how to do a fuse tap on that. Will tapping any of the other fuses accomplish what I want? Or is there a way to tap an MCASE+? Thank you!

 

[HAL9001]

If I was to wire a lighted bug shield to turn on with the marking/parking lights, which fuse should I wire it to?

thanks!

Tapping a fuse will only supply 12 VDC power to an accessory either with constant power or power with the ACC/IGN on. All other switching takes place after the fuse. So, if you tapped a fuse, the lighted bug shield would either be on all the time or turn on when the ACC/IGN was on.

If you want the lighted bug shield to turn on with the marking/parking lights, you would need to tap into a wire that supplied power when the marking/parking lights were on. It would then, by default, be fused by the circuit that supplies power to the marking/parking lights.

The caveat with that is if your add-on accessory required more power than the existing fuse could handle, you could blow the fuse. You always have to be careful tapping into an existing circuit not to overload it. Fortunately, LED lights do not require a lot of power, so you should be able to get away with it.

Here are simplified descriptions of typical vehicle power:

12 VDC Battery/Alternator Power ---> Fuse ---> (Any Device Switching) ---> Devices in the Circuit
or
12 VDC Battery/Alternator Power ---> ACC/IGN Switching ---> Fuse ---> (Any Device Switching) ---> Devices in the Circuit

 

[HAL9001]

Man this is so amazing, you must’ve spent a ton of time on all that! Thank you very much for posting it. I have white puddle/under glow lights that I really want to turn on every time the standard mirror puddle lights come on (I.e when you unlock or open a door, etc) and I’ve always thought I should tap into F36 (exterior light fuse) but it’s an MCASE+ fuse & idk how to do a fuse tap on that. Will tapping any of the other fuses accomplish what I want? Or is there a way to tap an MCASE+? Thank you!

Please see my reply directly above this post. Tapping into a fuse will not supply power that will turn on/off with another light. You must tap into the light's circuit to do that.

I have not yet found an MCASE/MCASE+ fuse tap.

 

[McRaminic]

I can't figure out which fuse is for the 115v AC? Neither the one in front or rear seat is working, even with truck running. I plugged in my laptop and think fuse blew...

 

[securityguy]

I can't figure out which fuse is for the 115v AC? Neither the one in front or rear seat is working, even with truck running. I plugged in my laptop and think fuse blew...

Did you check the manual? Looks like it is F35 on the cabin fuse panel below the steering column.

New 5th-Gen 1500 Fuse / Relay / Circuit Breaker Diagrams & Documentation

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...

5thgenrams.com

 

[McRaminic]

I looked but wasn't sure what it was called in the manual. Also both outlets are dead and I thought they are on separate fuses.

Sent from my SM-N970U using Tapatalk

 

[Jarrambidez]

This is a long shot, but I’m having a automatic grill shutter issue. Seems there is intermittent power supply. One theory is bad cables (less than 3 years old) or bad PDC/PCM.
I’ve done extensive trouble shooting and in my
Opinion it’s a bad PCM, however the idea of issues with the PDC have aroused.
Any thoughts?

 

[securityguy]

This is a long shot, but I’m having a automatic grill shutter issue. Seems there is intermittent power supply. One theory is bad cables (less than 3 years old) or bad PDC/PCM.
I’ve done extensive trouble shooting and in my
Opinion it’s a bad PCM, however the idea of issues with the PDC have aroused.
Any thoughts?

Are you under warranty or over in miles?