possible cause

[Brett63]

What would or could be the probable cause for the bottom 7.5a fuse located on the BIRD board in the picture labeled PCB PWR to constantly blow?

We are sitting parked, plugged in to 50a power and it is blowing at least everyday. I don't sit out and stare at it but when I check on it it has blown again.

Not sure why the picture posted so far below the text...Sorry

[Gary M]

2 minutes ago, Brett63 said:

What would or could be the probable cause for the bottom 7.5a fuse located on the BIRD board in the picture labeled PCB PWR to constantly blow?

We are sitting parked, plugged in to 50a power and it is blowing at least everyday. I don't sit out and stare at it but when I check on it it has blown again.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Not sure why the picture posted so far below the text...Sorry

I am no help with your issue, but as far as the space in your post, I found if I notice the space, I go back and do a small edit and save it goes back to normal. I think Scotty was working on it but with his wife sick ( prayers) he has that as a priority. 

[Brett63]

5 minutes ago, Gary M said:

I am no help with your issue, but as far as the space in your post, I found if I notice the space, I go back and do a small edit and save it goes back to normal. I think Scotty was working on it but with his wife sick ( prayers) he has that as a priority. 

Yea I tried that, that's why it says edit....didn't change anything...lol

[Chuck B 2004 Windsor]

A steady ground.  Chuck B 2004 Windsor

[DavidL]

If the fuse is blowing, than there is either a short or the circuit is drawing more current than what it is designed for.

So, a bad ground, a shorted BIRD, a chafed wire to ground, etc.   You need to get a schematic of that circuit and then split the circuit in "half" and measure current to ground on the fuse to isolate where the issue is.   But you need the schematic so the circuit can be traced to know what is powered by that circuit.

[Ray Davis]

When you go to edit can't you click just above the picture and backspace the picture until it's close to the message?

[Larry Maida]

I was always lead to believe that if a fuse is blowing its a safety feature. The alternative is a fire. I would suggest you find the cause instead of feeding it fuses. 

Edited February 27, 2022 by Larry Maida

[Brett63]

1 hour ago, Larry Maida said:

I was always lead to believe that if a fuse is blowing its a safety feature. The alternative is a fire. I would suggest you find the cause instead of feeding it fuses. 

I have been searching for a cause for a couple days, but thanks.

[Frank McElroy]

Brett, in looking at the schematic I sent you for this board, it is very likely that the big boy solenoid or associated wiring is failing.  Since you already have a spare big boy, I'd swap it out and see if that solves the problem.  When doing the swap, look carefully at the wires going to the solenoid coil.  A loose wire at the solenoid coil connection could also cause high current draw.

[Ivylog]

It’s the BigBoy going bad. You can go to a 10 amp fuse for awhile but if you do have another BigBoy, put it in.

Edited February 28, 2022 by Ivylog

[joefromperry]

I had the same issue with the fuse blowing on my 2003 signature. I pulled the big boy and took it apart, cleaning the corrosion, etc. It wasn't difficult to do. When I put it back together, the fuse stopped blowing. Been good for a year now.

 

[Ivylog]

14 hours ago, joefromperry said:

I had the same issue with the fuse blowing on my 2003 signature. I pulled the big boy and took it apart, cleaning the corrosion, etc. It wasn't difficult to do. When I put it back together, the fuse stopped blowing. Been good for a year now.

 

Not sure how cleaning the contacts changed the resistance of the coil that engages the contacts. Taking the small energizing wires off and back on maybe.