Please help a non-electrician

[ulm4lyf]

Blower motor fuse keeps blowing. It's a 20 amp fuse. If I put in a 30 amp fuse, the blower motor works until I put it on 'high' then it blows the 30 amp fuse. It has a new blower motor, new switch, new relay, and new resistor. I'm not seeing any obvious loose ground wires anywhere. I've looked online some and it looks like in some models there is an additional fuse under the hood, but I haven't seen one of those.

 

[SirRobyn0]

Blower motor fuse keeps blowing. It's a 20 amp fuse. If I put in a 30 amp fuse, the blower motor works until I put it on 'high' then it blows the 30 amp fuse. It has a new blower motor, new switch, new relay, and new resistor. I'm not seeing any obvious loose ground wires anywhere. I've looked online some and it looks like in some models there is an additional fuse under the hood, but I haven't seen one of those.

This is probably the simplest way for someone not into electrical to figure this out. Get a bunch of 20 amp fuses. Disconnect the blower motor, tape connector so it can't be grounded accidentally install new fuse, see if it blows. If it blows keep going down line disconnecting the resistor next, then the relay. When you get to the problem component the fuse won't blow. Just remember a new component should me a good component, but doesn't always, especially with reman'd parts. Also do a good visual inspection on the wiring. If the fuse is still blowing then do an even better inspection of the wiring.

If that doesn't work out then we can consider getting out a meter and running tests, but I'm trying to keep this as easy as possible for you.

Also would be good to know why all that stuff was replaced in first place, was it blowing the fuse too?

 

[Juggernaut]

Check and see if one of the wires gets noticeably hotter than the others and start tracing from there

 

[ulm4lyf]

This is probably the simplest way for someone not into electrical to figure this out. Get a bunch of 20 amp fuses. Disconnect the blower motor, tape connector so it can't be grounded accidentally install new fuse, see if it blows. If it blows keep going down line disconnecting the resistor next, then the relay. When you get to the problem component the fuse won't blow. Just remember a new component should me a good component, but doesn't always, especially with reman'd parts. Also do a good visual inspection on the wiring. If the fuse is still blowing then do an even better inspection of the wiring.

If that doesn't work out then we can consider getting out a meter and running tests, but I'm trying to keep this as easy as possible for you.

Also would be good to know why all that stuff was replaced in first place, was it blowing the fuse too?

"Also would be good to know why all that stuff was replaced in first place, was it blowing the fuse too?"

Yeah. NOT an electrician so OF COURSE I replaced everything before ever checking the fuse. I know. I'm already kicking myself.

 

[SirRobyn0]

"Also would be good to know why all that stuff was replaced in first place, was it blowing the fuse too?"

Yeah. NOT an electrician so OF COURSE I replaced everything before ever checking the fuse. I know. I'm already kicking myself.

Understood. Also Greg's advise is good. Especially if your testing and have gone though a few fuses, you might be able to feel a warm or hot wire, that might lead you to the cause.

 

[Doppleganger]

How difficult would it be to physically trace the wires back to their source? I ask in the event you have a short or perhaps a sharp edge that has cut into a wire. Also - what else is on that circuit (fuse)? fwiw....I have had resistors and switches both - on NEW blowers - be defective.

Electrical gremlins are the #1 reason people get talked down from bridges. lol

 

[Terry Wilkerson]

If you see a place on the wire where there is a previous repair or electrical tape is start there with your inspection. Not uncommon to find previous owners repairs don't do you any favors.

 

[Ricko1966]

Get a 194 bulb and socket,pictured below use that instead of a fuse. Now wiggle your harness in multiple locations while watching the light. The light will go out when you eliminate the short it will probably flicker when you are wiggling the right section of harness. No flicker in the harness do what Robyn said but use your light instead of fuses,the light will go out when your short is gone but you will not burn up a million fuses. It doesn't have to be a 194, and I suppose you could use ac194 without a socket by just twisting wire leads into the contact loops at the base of the bulb. Personally I just clipped the pigtail with the bulb in it out of a parts car crimped on 1/4 male terminals just so I could plug it in place of fuses,it is a permanent part of my electrical tool box now

 

[WP29P4A]

Yeah. NOT an electrician.

That's a good thing. The two systems are so vastly different that most electricians don't know chit about low voltage. I see this on a regular basis when electricians pretend to be a low voltage guy, and then I get to correct what they pretended to know.

 

[SirRobyn0]

That's a good thing. The two systems are so vastly different that most electricians don't know chit about low voltage. I see this on a regular basis when electricians pretend to be a low voltage guy, and then I get to correct what they pretended to know.

I agree with this. For me I learned car voltage first, and when we first bought the farm, I mean I could replace a simple out let or fixture but didn't realize all the differences until later on. I think we discussed this some in another thread but anyhow yes it's a bit different.

 

[Snoots]

You must be registered for see images attach

 

[coops79]

Blower motor fuse keeps blowing. It's a 20 amp fuse. If I put in a 30 amp fuse, the blower motor works until I put it on 'high' then it blows the 30 amp fuse. It has a new blower motor, new switch, new relay, and new resistor. I'm not seeing any obvious loose ground wires anywhere. I've looked online some and it looks like in some models there is an additional fuse under the hood, but I haven't seen one of those.

 

[coops79]

Can you delete switch and test?
May have short in switch in high speed position.

 

[Camar068]

watching a few video's on youtube with a meter would help. You can troubleshoot with the ohm function just as easy as the voltage function on most things. Just gotta know how to understand ur readings.

If you can put your meter leads together and read zero ohms and understand that the connection is made with a zero reading, your halfway there.

1. wire up a 12v light bulb to a battery. Read battery, 12v. Read from positive or negative (your choice....just dont change that reference on the battery) to the other end of the wire going to the bulb. You will read zero. Go to the other side of the bulb, you will read 12v. Now take the bulb out and read the end of each wire at the bulb. You will read zero on your reference, and 12v on the other wire. Guess what, you just verified that you have a (simulated) blown fuse, broken wire, or bad bulb, because u read zero.....then across the open plug you read 12v.

2. Similar thing, wire up a 12v light bulb WITH NO BATTERY POWER CONNECTED. Read from the positive or negative (your choice....just don't change your reference) wire and read the wire going to the bulb. You will read zero. Go to the other side and you'll get a small increase in OHMS (2-20). Now take the bulb out and read the end of each wire connecting to the bulb. You will read zero ohms on one leg, and OL (infinity or very high) on the other leg. Again, you just verified that you have a (simulated) blown fuse or broken wire or bad bulb, because u read zero....then across the open plug you read OL (or infinity/high) OHMS.

NEVER EVER PUT THE METER IN THE OHM FUNCTION WITH BATTERY POWER CONNECTED!!! You'll blow the fuse inside the meter and you won't be able to use the ohm function until you open the meter and change the fuse.

Another tip, if you're troubleshooting something that is of great distance.......such as the fuel sender wire to the gauge. Get a long length of speaker wire to extend your meter leads.

Like I said before the #'s, to test your meter, put it on ohms and put the leads together and you should read zero OHMS. If you don't your meter has a blown fuse or bad meter leads. Then go to town with the above #'d steps.

Hope this helps

 

[Randy and Easton]

That is a great example and explanation