luv2ski

Bare with me guys, i'm new to the forum.
When i connect my 7 pin plug in from my boat trailer I keep popping the fuse under the hood of my 2001 suburban. When I connect it in to my RV I don't pop the fuse on the RV.
The fuse box under the hood of suburban uses the small flat blade style fuses.
While trying to diagnose the problem I ran out of fuses. so, i connect two jumper wires from the fuse block to a large flat blade fuse that I had and the fuse did not pop. The large flat blade fuse that I used was the same amperage as the small flat blade fuse. How does this happen??

in2pro

luv2ski Welcome to the forum

Are both 7 pin harness connectors on your truck and RV factory installed?
If not start there...
If they are are, I would suspect that the trailer wire harness is the culprit and that the RV connector may not have all the same connections as the truck...

The blade fuse may have been the same amperage rating but could have been a higher voltage rating...

Attached is what the pin out should look like

luv2ski

How come when i connect two jumper wires from the same fuse block to a separate large flat blade fuse it doesn't pop? Aren't all 2001 chevy's a 12 volt system.

in2pro

I guess to better clarify my question, is the large blade fuse you're using also rated at 12v or is it a higher voltage rating? (Is it an automotive type fuse)

Does everything work correctly when you use the larger blade fuse?

luv2ski

Yes, the large blade fuse is an automotive type fuse. I would assume it is 12 volt.
Yes, everything work correctly when I use the larger blade fuse.
thx for the help
The fuse looks like this.
Pretty sure I got it out of my old car. Not sure how to tell what voltage it is.

in2pro

One more question, had it worked in the past or was this the first time?
If it worked in the past, I would suspect a short or near short (pinched wire) somewhere in the harness of the truck...

What is the fuse rating for that same line in the RV?

What is the fuse size that is blowing? if its low like 3 or 4 amp you might try a 5 amp, but if its 10 or so I'd want to dig a bit deeper to find out why its blowing...

luv2ski

Yes, it worked in the past. The fuse rating for the RV is 15 amp.
The fuse size that is blowing is a 15 amp.
I tried 4 spare fuses in the fuse box of the suburban and they all blew.

The wife bought me a box of 15 amp small blade fuses and I put one in and it now works. Doesn't make a lot of sense.

Maybe my wife put 4 bad spare fuses in the suburban to keep me pre occupied all day.
in2pro thanks for all the help...

in2pro

You're very welcome

It is possible the fuses could have been mis-labeled / rated...

SWHouston

You could do a Short Test.

Remove all the Bulbs out of the Lamp Housings on the Trailer.
Connect an Ohm Meter between Ground and each Blade sequentially, on the Trailer Connector.
Possibly you'll find one/more Lines that show a closed/shorted circuit.
Trace that line out and replace/tape it where it's Frayed/shorted to Ground.

Use the Diagram that in2pro gave you, to help find the wire route.
Inspect all the Fixtures which have been submerged for corrosion,
that can act as a short even when not apparent.