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New wild horses heat blaster blows 20 amp fuses when turned on

Crazyhorse1977

New Member
Joined
Oct 5, 2017
Messages
11
Loc.
Clovis Ca.
Good evening all,
I purchased a new heat blaster motor for my 77, rebuilt the housing, new seals and reinstalled. Everytime the heater is turned on it blows the 20 amp fuse in my new Ron Francis Bare Bones fuse panel. The old motor never did that?
I installed per the directions or lack of lol. It will turn on for a minute then blows the fuse.. btw the fuse panel has two fuses, a 20 and a 15( or 10 cant remember, my son drives it) that go to the " ign" labeled fuse ports. Any ideas?
 

DirtDonk

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Nov 3, 2003
Messages
47,355
Hey Crazyhorse, welcome to classicbroncos! Sorry to hear you're having trouble right off with one of our products.

And you're right to assume that's not normal from what I know anyway. But first have you verified that the squirrel cage fan is not interfering with something and jamming up the motor?
And while it should not normally matter in a case like this, is the ground wire running to a good ground? Not that Broncos have many good grounds, but it's normally sufficient for the motor upgrade.

Can you try connecting it while outside the case to see if it still blows?
I've never heard of one needing a bigger fuse, but I wonder if a 30 amp will blow. I believe the new Ron Francis wire is able to handle the 30 amps, but not really totally sure on that score. Don't know the gauge (but it's probably 14ga) and don't know how long it is. But with that knowledge we can check to see if a 30 amp works.
But that's a Band-Aid really.

I guess there's nothing for it than to pull it out again and see what it's doing on the outside.
If nothing seems to work let us know and we can at the very least try another unit.

Crossing fingers it's something simple.

Paul
 

Pa PITT

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Jul 15, 2005
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11,252
Loc.
Stephenville TEXAS
... I was thinking that most heaters use a 30 amp. But I too figure the cage is binding.
Maybe not pushed all the way onto the stem of the motor ... Seems like I had one do that to me a few years ago .
....................
....... BUT MIME TRIED TO SCRATCH IT'S WAY THROUGH THE CASE.
 

DirtDonk

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And which RF harness are you using? I see Bare Bonz, but which part number?
Might not matter, but it's more to make sure.

Paul
 

taipeichris

Bronco Guru
Joined
May 11, 2006
Messages
1,752
Hi Guys,

My heater did that years ago too. I bought a massive Cheby blower motor from Kragen for my heater and a squirrel cage big enough for a family of Raccoons and sure enough, spin-spin-spin, blow-blow-blow and quiet. Dead fuse, no Bueno.

The evil culprit was the set screw on the cage. It was not staying on the motor shaft and I had to "mark and notch" the motor shaft with a file to keep that sucker in place. Good luck with the hot air blowing endeavors.
:cool:
 
OP
OP
Crazyhorse1977

Crazyhorse1977

New Member
Joined
Oct 5, 2017
Messages
11
Loc.
Clovis Ca.
All, thanks for the responses, great people. I did check the motor before install and it worked great after I got a good ground. Grounds are all to junction block in tuffy glove box next to fuse panel. When I installed into housing it was a tight fit under there so I was worried about the power wire I cut the new splice fitting on. I did see the motor send small puff of smoke twice near the power connection? I need to check the model number of the bare bones kit. Could it be the resistor connections on the firewall side? Gonna tear it apart this weekend and talk a look if I can't figure it out. Motor case didn't run long enough to get hot and sounds like the squirell cage was not rubbing but I will verify this.
 

DirtDonk

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Messages
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While it could be benign, ANY smoke is bad smoke when it comes to electrical. Period.
So you do need to find out why it was doing that. But it would sure be indicative of why the 20 amp fuse is blowing.
Takes typically more than 20 amps to create smoke in a wire like that I would think. But "resistance" causes heat too, which creates smoke if hot enough. So you definitely need to check the smoking connector to make sure it's not working against you.

And as mentioned, many of the big trucks (like the ones this motor came from) utilize 30 amp fuses on that circuit.
Now, that could be due to the larger motor pulling more current. Or it could be that other trucks use that same fuse for more different loads.
But, and I hate saying this... You might just try a 30 amp fuse to see if it blows. Maybe you're simply overpowering the smaller fuse during initial startup.

That said, if you do try that make sure to keep an eye on things right then upon first fireup to see if you see smoke again anywhere. If you do, just turn the switch off and pull the 30 amp fuse out of there.

Then find the short/problem that is blowing the fuse and making smoke signals in your harness.

Good luck.

Paul
 

BGBronco

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Tennessee
Installed today, no issues. Took a few more hours than it should have but this was a nice upgrade since I'm topless most of the year!
 
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OP
Crazyhorse1977

Crazyhorse1977

New Member
Joined
Oct 5, 2017
Messages
11
Loc.
Clovis Ca.
All, thanks for you responses, I checked wiring and found nothing. I installed a new 20 amp fuses and my son used the heater about 5 or 6 times the past month or so and it worked flawless until 2 days ago! He turned the heater on and fuse blew. I'm wondering why it worked for a month then just blew out of no where?? No more smoke from the motor. Thinking the motor is had maybe?? Paul, thoughts?
 

DirtDonk

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Messages
47,355
Yep, one more thought. Install a 25 amp fuse.
If there is an intermittent short in the wire, or an actual problem with the motor, then even a 25 will blow and your wiring is still in no danger of overloading.
As we said earlier, many of the full-size trucks that are the source of this larger motor use a 30 amp fuse from the factory. So it comes back down to it might be as simple as being just barely overloaded.

Why it worked fine for a few weeks is a mystery at this point. Can you ask your son if he remembers was the fan running on the higher speed, or lower speed most of the time when the fuse was fine? Or was it on low speed and maybe the fuse blew once it was turned up to high speed? Is yours still wired up so that it turns on to high-speed at the first click and low speed at the second? Or is it reversed, with low being first?
Just out of curiosity, in case that leads us to another clue.

The bottom line though is that if it blows a 25 amp fuse give us a call and we'll send you a new motor just to see if it's just that your particular motor is pulling more amps than normal, like you or someone was surmising originally.

The fact that there is no more smoke is a good thing, as long as the motor is actually still working and blowing air.
I think it's just borderline and needing a bigger fuse to handle the bigger motor. But when in doubt, we'll replace it.

Paul
 

DirtDonk

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While we're on the subject of oversizing the fuse...
The wire and other accessories will be fine with the higher capacity fuse. But I would still keep an eye on the motor for more smoking.

No smoke is good smoke.

Paul
 
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