Blower fuse keeps breaking

[JaredB]

I just bought a 2007 Tahoe Q4L with the Mercruiser 3.0 in it. The blower was not working when I bought it, I changed the fuse and it started working. It worked last night with several tests. Got home from work today and hooked it up with ear muffs to run the motor, blower came on, I started the engine, and blower quit. It blew the fuse again. I took off the hose off the top of the blower, changed fuse again and it worked fine and was blowing air fine. Help please!!!

 

[Dshow]

Re: Blower fuse keeps breaking

Can you measure the current the blower is drawing to see if it's drawing more that rated? If not, I would say it's time for a new blower.

 

[Bt Doctur]

Re: Blower fuse keeps breaking

the 10 or 15 A fuses rarely blow unless motor is drawing too much current.

 

[NHGuy]

Re: Blower fuse keeps breaking

yup, if the motor is worn it needs more power, but once it needs more power than it's designed for, it blows fuses. That's a safety protection. Toss it.
They are not serviceable, new are cheap. Just get the same shape and rating so you don't have to re rig, wire, and plumb it.

 

[JaredB]

Re: Blower fuse keeps breaking

Not sure how to measure that. It has a 10A fuse in it

 

[Bt Doctur]

Re: Blower fuse keeps breaking

then its time for a new blower

 

[JaredB]

Re: Blower fuse keeps breaking

Ok I will try a new one. Weird that it only blows the fuse when the engine is running. Thanks everyone for the help!!

 

[bruceb58]

Re: Blower fuse keeps breaking

What size fuse are you using?

 

[Thalasso]

Re: Blower fuse keeps breaking

What size fuse are you using?

(Quote)
It has a 10A fuse in it

 

[UncleWillie]

Re: Blower fuse keeps breaking

Ok I will try a new one. Weird that it only blows the fuse when the engine is running. Thanks everyone for the help!!

That could be because it is right on the edge and with the engine OFF it is operating on 12 volts.
With the engine running it draws a little more current operating on the alternator's 14 volts.

OR.....

There is a wire with a bad piece of insulation that has worn through from rubbing against something,
and the vibration of the engine causes it to short out intermittently.

Before you replace the blower for naught, inspect the wiring very closely.
The new blower will have the same issue if it really a wiring problem. :blue:

A Test...
Unplug the blower. Run the Engine. If the fuse blows again, it is not the Blower. :joyous:

...Not sure how to measure that. It has a 10A fuse in it

Remove the fuse.
Place an AMP Meter rated for at least 10 AMPs across the fuse terminals.
Switch on the Blower.
Read the current on the meter. The common 4" Blower fans typically draw ~3 amps.

 

[bruceb58]

Re: Blower fuse keeps breaking

(Quote)
It has a 10A fuse in it

I swear I looked too.

 

[Bondo]

Re: Blower fuse keeps breaking

I swear I looked too.

Ayuh,.... They say the eyes are the 2nd thing to go,........... :lol:

 

[NYBo]

Re: Blower fuse keeps breaking

That could be because it is right on the edge and with the engine OFF it is operating on 12 volts.
With the engine running it draws a little more current operating on the alternator's 14 volts.

OR.....

There is a wire with a bad piece of insulation that has worn through from rubbing against something,
and the vibration of the engine causes it to short out intermittently.

Before you replace the blower for naught, inspect the wiring very closely.
The new blower will have the same issue if it really a wiring problem. :blue:

A Test...
Unplug the blower. Run the Engine. If the fuse blows again, it is not the Blower. :joyous:.

I believe current draw drops with higher voltage.

If the fuse blows as soon as the engine starts, my guess would be a wiring problem. To clarify UncleWillie's suggested test: Disconnect the wires at the blower, turn on the blower switch, and start the engine. One warning: ventilate the bilge with the blower for 4 minutes, then work through the testing steps as quickly as possible so any gas fumes don't have a chance to build up.

 

[bruceb58]

Re: Blower fuse keeps breaking

I believe current draw drops with higher voltage.

Not necessarily. Current will likely go up, just not linearly.

 

[JaredB]

Re: Blower fuse keeps breaking

Ok so I ordered a new blower today and was going to go ahead and pull the old blower off to get ready to replace. When I got the old blower off I found that a piece of what looks like masking tape had gotten sucked into fan and trapped between one of the fan blades and the housing. The fan could still spin but with resistance. Was that my problem?

 

[GA_Boater]

Re: Blower fuse keeps breaking

Could be. Try it without the tape and see what happens.

Sometimes it's the simple things.

 

[UncleWillie]

Re: Blower fuse keeps breaking

Ok so I ordered a new blower today and was going to go ahead and pull the old blower off to get ready to replace. When I got the old blower off I found that a piece of what looks like masking tape had gotten sucked into fan and trapped between one of the fan blades and the housing. The fan could still spin but with resistance. Was that my problem?

Could be. Try it without the tape and see what happens.
Sometimes it's the simple things.

+1
The slower the motor turns, the higher the current it will draw.
Always determine what the problem is before you go replacing parts.
Throwing money at the problem is an expensive way to troubleshoot.

...Before you replace the blower for naught, inspect ...