Upfitter #2 BD S8 30 Fuse Blowing

[greatone99]

The inline fuse in the wiring harness or the up fitter fuse?

You’ve gotten some good suggestions already, but before throwing a relay at it, I’d test to see if there’s a short. If you wire pos. directly to the battery, does the inline fuse pop?

What do the wires look like- inspect from the light to the connection points.
How are the connections?

If everything checks out, you have good crimps, no severe bends in the wiring, etc. a relay is probably a good idea. Maybe not technically “required” but probably better overall.

I agree sounds like a short ,maybe when the truck is bouncing around ,a bad connection will also draw more amps ,and a bad ground or to high a resistance ground , . but im still dumbfounded what a relay will fix its just a switch .

 

[OEMPlus Raptor]

The inline fuse in the wiring harness or the up fitter fuse?

You’ve gotten some good suggestions already, but before throwing a relay at it, I’d test to see if there’s a short. If you wire pos. directly to the battery, does the inline fuse pop?

What do the wires look like- inspect from the light to the connection points.
How are the connections?

If everything checks out, you have good crimps, no severe bends in the wiring, etc. a relay is probably a good idea. Maybe not technically “required” but probably better overall.

It's blowing the up fitter fuse. The S8 does not come with inline fuse.

So I noticed I did have the excess wire from the harness wrapped up to make it shorter (sharp bends). I had it pretty tight and had zip ties holding the bundle. I was also sharing the ground point with my other BD lights.

Here's what I did so far, but I now need a new fuse to check and see if these things will work. First I grounded my S8 by itself to a new ground, by the headlight and battery. I also cut down the harness to a smaller length where I wouldn't need to bend and wrap the excess harness. I'm using weather pack connectors and they're solid. Harness is a lot shorter now. When the light bar is on, it works just fine. I doubt it has any issues.

If the problem continues would I be able to use a relay and my up fitter switch at the same time? Or would it require another switch mounted on the dash somewhere?
Thanks for all the help.

 

[CobraJay]

Once you get your new fuse in try swapping another known good light over to switch 2 and see if it still blows. That will tell you if it is indeed the light bar/wiring or something else. So far everything you have done so far to troubleshoot seems on point. I would also check all crimps/solder connections.

If you decide to run a relay the way it works is your aux switch will turn the relay on/off (close/open) and the aux fuse will only be affected by the amp draw from operating the relay. The light will have its own separate inline fuse that you will need to add. The light power will run from the battery > fuse > relay > light. With the aux switch off the relay will be open, no power applied to the light. Aux switch on the relay will close and apply voltage to the light.

 

[xrocket21]

I wonder if they draw more amps on startup ? usually the biggest amp draw on anything is the startup

not a lot of inrush on LEDs

 

[CobraJay]

When the light bar is on, it works just fine.

Just caught this part, if the light works for a while and then blows the fuse some time later then I would most definitely look at the wiring real close. If the wiring/connections look good, ohm out correctly and a known good light works fine on aux2 I would say you have a bad light.

 

[OEMPlus Raptor]

Just caught this part, if the light works for a while and then blows the fuse some time later then I would most definitely look at the wiring real close. If the wiring/connections look good, ohm out correctly and a known good light works fine on aux2 I would say you have a bad light.

Thanks man, for your input. I'll definitely look at all the things you pointed out.

 

[smurfslayer]

It's blowing the up fitter fuse. The S8 does not come with inline fuse.

ok... it’s been a few years, and I originally had cheaper behind the grille lights before the s8 so that may be correct.

So I noticed I did have the excess wire from the harness wrapped up to make it shorter (sharp bends). I had it pretty tight and had zip ties holding the bundle. I was also sharing the ground point with my other BD lights.

Here's what I did so far, but I now need a new fuse to check and see if these things will work. First I grounded my S8 by itself to a new ground, by the headlight and battery. I also cut down the harness to a smaller length where I wouldn't need to bend and wrap the excess harness. I'm using weather pack connectors and they're solid. Harness is a lot shorter now. When the light bar is on, it works just fine. I doubt it has any issues.

ok, maybe. the multi-strand auto wire is pretty resilient unless abused pretty hard. You mentioned that you were sharing ground, which is ok if it’s a good ground. You could narrow it down by cutting in a 15a fuse, and running a home run to the battery positive. if your new 15a inline fuse blows, you can be pretty certain it’s harness - and a relay isn’t going to help of fix that.

If you blow the fuse again with the cut down harness, replace the harness wires, period. If you’re really concerned about knowing exactly where the problem is/was, do it one wire at a time, and continue to test until you stop popping fuses. Or you can just re-wire the whole thing and be done with it. -- this is if you haven’t already resolved by cutting out the possibly defective part of the harness.

If the problem continues would I be able to use a relay and my up fitter switch at the same time? Or would it require another switch mounted on the dash somewhere?

Don’t wire in a relay if you haven’t fixed the fuse popping. Fix problem 1 first.
A relay isn’t a bad idea but again it’s probably not technically necessary. @CobraJay has well explained the relay and effect for you.

 

[greatone99]

I would think the relay coil would burn eventually if it is a short issue , as the guy said above a relay is not fixing the issue , just masking over it

 

[Sheeepdog18]

Also check the gauge of the wires too. Are you using the BD wire harness? Installing a relay is never a bad idea.

 

[sixshooter_45]

12 amps according to there website.

They do state 12A but it's also rated at 80W which is 15A on a 12V system and they have three different configurations.

The best way is to put an amprobe on it and measure the amperage. Also stay within 80% of rated amperage or else go with a relay.

I would think the amperage would rise somewhat to a certain degree the longer they're on as LED'S run hot.