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I know that ultimately I will need to speak with J&M but this forum is so great so I thought I would start here….

2020 RGL…purchased J&M 800W 4-channel amp along with their front and rear 6.5’s…. Get everything hooked up and… no sound. Go over every connection again and again and again… nothing missing, no pinched wires, and… no sound. Looked a little further and can see that the fuse on the positive battery cable is blown. Replaced only to blow again and again and again. I’ve followed their instructions to a tee, including grounding the power cable to the same grounding screw that the negative battery cable is grounded to. A good, clean ground (my research shows very clearly that not having good ground could be the culprit, but my ground connection is spot-on). Even when removing all of the other amp connections (speakers, remote turn on, etc…) every single time I plug JUST the amps’ power wire in… pop goes the fuse. Just for shits and giggles I plugged in and old Hogtunes amp that I had used previously and… no blown fuse at all. My conclusion is it’s gotta be the amp, but before I get involved in shipping it back and waiting for a diagnosis / replacement I thought I would check here for thoughts and suggestions.
 

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I know that ultimately I will need to speak with J&M but this forum is so great so I thought I would start here….

2020 RGL…purchased J&M 800W 4-channel amp along with their front and rear 6.5’s…. Get everything hooked up and… no sound. Go over every connection again and again and again… nothing missing, no pinched wires, and… no sound. Looked a little further and can see that the fuse on the positive battery cable is blown. Replaced only to blow again and again and again. I’ve followed their instructions to a tee, including grounding the power cable to the same grounding screw that the negative battery cable is grounded to. A good, clean ground (my research shows very clearly that not having good ground could be the culprit, but my ground connection is spot-on). Even when removing all of the other amp connections (speakers, remote turn on, etc…) every single time I plug JUST the amps’ power wire in… pop goes the fuse. Just for shits and giggles I plugged in and old Hogtunes amp that I had used previously and… no blown fuse at all. My conclusion is it’s gotta be the amp, but before I get involved in shipping it back and waiting for a diagnosis / replacement I thought I would check here for thoughts and suggestions.
Okay re-read what you wrote bud, so we are understanding correctly to assist.

You said: “I’ve followed their instructions to a tee, including grounding the power cable t the same grounding screw that the negative battery cable is grounded to....”

Just want to make sure you didn’t mean you grounded the power to the ground screw first, if that’s statement is not correct then it sounds like either the cable might have a bare spot along the wire somewhere and grounding out, amp may be bad.
 

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Discussion Starter #3
Okay re-read what you wrote bud, so we are understanding correctly to assist.

You said: “I’ve followed their instructions to a tee, including grounding the power cable t the same grounding screw that the negative battery cable is grounded to....”

Just want to make sure you didn’t mean you grounded the power to the ground screw first, if that’s statement is not correct then it sounds like either the cable might have a bare spot along the wire somewhere and grounding out, amp may be bad.
Sorry if I wasn’t clear…. I attached the negative (black) cable to the bikes grounding screw…. The same spot where the negative battery cable is grounded to. Then I attached the positive (red) cable to the positive post of the battery. I’ve checked the entire length of the cables… from end to end…. And there are no bare spots. I even swapped power cables as I have one from an older amp. The same results happen each time. That’s why I am concluding that it’s the amp as I have pretty much eliminated any other possibility… unless I am missing something?
 

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Discussion Starter #5 (Edited)
Well, for as much troubleshooting I did, there is one thing I didn't do, and it is really gratifying to know that I figured this out and got things working..... Prior to installing this J&M setup I had a small Hogtunes amp installed, and instead of using J&M's supplied power cable I just used what was already installed. It's the same gauge wire and the same, exact connector to the amp, so I figured a wire is a wire is a wire, right? Well, no it's not. I don't know what makes J&M's power cable specific to them.... but it is. I swapped out my old power cable for the J&M included cable and..... what is that sound I hear? Is it music?????? Yes sir it is!!!!!

All in all I must admit that while it was a very frustrating and time consuming process I feel really good having learned quite a bit about proper wiring.
 

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Have you contacted John of J&M (JMJOHN) here on the forum.
J&M are a Vendor here on RoadGlide.org. I’m sure he can help, and expedite any problems found.
 

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Glad you got it fixed. Out of curiosity which ground stud did you use? There are two grounding studs located on the frame, one on the left side and one on the right side just in front of the battery. On my 2020 RGS the one on the right side has two black wires with green stripes. Theses wires are the grounds for the ECM & BCM control modules. My understanding is this grounding stud should not be used for anything else.
 

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Discussion Starter #9
Everything I've read said to NOT use the grounding screw on the left side for ANYTHING. That's the one with the grounds for the ECM & BCM control modules. On my bike (2020 RGL) the one on the right side ONLY has the negative terminal of the battery connected it. That's the one I used.
 

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Agreed. I wonder why the ECM and BCM grounds would be on different sides on the RGL and RGS?

Makes sense battery grounding stud is on the top of the transmission.
 

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Discussion Starter #11
Not sure either. The only thing I can think of is the fact that on the Limited we’ve got all the tour pack wiring to deal with, so maybe the way the wires run back to front is different between the two models? Either way, as long as we are able to identify which grounding post to stay away from them all is good.
 

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So the cable that you replaced had a spot where it was grounding out?

Sent from my SM-N970U using Tapatalk
 

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Discussion Starter #13
So the cable that you replaced had a spot where it was grounding out?

Sent from my SM-N970U using Tapatalk
I couldn’t find any bare spots on the old cable. But, there are 2 major differences between the two cables… First, J&M’s cable is sheathed from end to end in this thick, rubberlike covering, which over the standard sheathing so the actual wire is majorly insulated … Hogtunes cable does not have any secondary sheathing. They are both the same guage wire underneath. Also, the J&M in-line fuse holder is much beefier than the Hogtunes one. Between these two physical differences I guess the J&M amp draws different / more than the Hogtunes one, necessitating a more elaborate power wire.
 

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Well, for as much troubleshooting I did, there is one thing I didn't do, and it is really gratifying to know that I figured this out and got things working..... Prior to installing this J&M setup I had a small Hogtunes amp installed, and instead of using J&M's supplied power cable I just used what was already installed. It's the same gauge wire and the same, exact connector to the amp, so I figured a wire is a wire is a wire, right? Well, no it's not. I don't know what makes J&M's power cable specific to them.... but it is. I swapped out my old power cable for the J&M included cable and..... what is that sound I hear? Is it music?????? Yes sir it is!!!!!

All in all I must admit that while it was a very frustrating and time consuming process I feel really good having learned quite a bit about proper wiring.
Glad that worked out fir you bud!
 

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Glad you got it fixed. Out of curiosity which ground stud did you use? There are two grounding studs located on the frame, one on the left side and one on the right side just in front of the battery. On my 2020 RGS the one on the right side has two black wires with green stripes. Theses wires are the grounds for the ECM & BCM control modules. My understanding is this grounding stud should not be used for anything else.
This is correct, you want to use the batteries ground for amps. Distribution block for multiple amps. Grounds to the frame is just not how it’s done on bikes. Can be done, yes, but 90% of the people here use the battery. Don’t think car audio when grounding. I, like many have 3 or more amps under the fairing running from battery ground to a distribution block.

Let me see if I can get the OG’s to respond on the technical reason why, lol. I personally think it’s because of the welds throughout the bike may not be a strong enough connection or because of the vibration. Hell screws back out over time on bike sometimes. My $0.02 on the matter.
 

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Good thing you got it figured out. I guess they send you wire for a reason :rolleyes: .
I have the 500 watt J&M amp and it works great but J&M doesn't make that amp anymore.
I'm sure you will like the new sound, enjoy.
 
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