Blower motor on while switch is off

[moparkrazed]

Hey guys, I’m close to getting my car back on the road (1975 Dodge Dart swinger with a 318). I wired up my motor and did a test fire the other day and it fired right up. I started hooking up my other wires last night and grounded the blower motor. I turned the acc switch on from the ignition and the fan started blowing but the switch was set at off. I turners everything off unplugged the battery and double checked my wires. I also noticed the fan speed selector was stuck. I got that moving up and down again but no the fan won’t come on at all. I’m heading back to the shop today to check fuses and to make sure I have power getting to the blower motor still. What could be the issue? A bad switch maybe? Thanks for any insight anyone can offer. I purchased a shop manual and studied it last night and the wiring appears to be correct.

 

[toolmanmike]

Let's see, the blower was on, the switch was stuck, you broke it loose and now it doesn't work at all. It's not the fuse. It's the switch.

 

[moparkrazed]

Let's see, the blower was on, the switch was stuck, you broke it loose and now it doesn't work at all. It's not the fuse. It's the switch.

That’s kind of what I was thinking. I don’t have a ton of experience with wiring. The car has been sitting in my uncles garage for a few years. Hopefully switching that out will work. I won’t need it until winter but also don’t want to overlook something and cause a bigger issue down the road or have something happen when I take my kids out for a drive. Thanks for the input toolmanmike

 

[Mike69cuda]

The fan switches have little pieces of sliding metal in them that slide across the the wire connections that go to the switch. This makes different connections depending on the switch setting. Sometimes they don’t move with the switch. The switch can easily be taken apart by bending the little tangs that hold it together. Most of the time they can be fixed and put back together if they are not worn too bad. Put a little grease on the sliding parts.

 

[toolmanmike]

That’s kind of what I was thinking. I don’t have a ton of experience with wiring. The car has been sitting in my uncles garage for a few years. Hopefully switching that out will work. I won’t need it until winter but also don’t want to overlook something and cause a bigger issue down the road or have something happen when I take my kids out for a drive. Thanks for the input toolmanmike

Switches might be a crap shoot. You might be able to find one at you local parts store or order from Classic Industries. The new switches can be poor quality. ( usually made in China) a used switch might be a better bet but it might be in the same shape yours is. Start a wanted thread and I bet someone will have one for you.

 

[moparkrazed]

The fan switches have little pieces of sliding metal in them that slide across the the wire connections that go to the switch. This makes different connections depending on the switch setting. Sometimes they don’t move with the switch. The switch can easily be taken apart by bending the little tangs that hold it together. Most of the time they can be fixed and put back together if they are not worn too bad. Put a little grease on the sliding parts.

Thanks mike. I appreciate the feedback. I’m a fish out of water on mechanical stuff but enjoying the learning process. I’m hoping to drive the car in the next couple of weeks. First time in 9 years. It’s the car my wife and I dated and and hopefully I’ll get to take the kids out on their first ride in it soon. Anyways, back on topic. I appreciate you taking the time to tell me some of the inner workings so I know how it works and how to fix it in the future.

 

[toolmanmike]

Thanks mike. I appreciate the feedback. I’m a fish out of water on mechanical stuff but enjoying the learning process. I’m hoping to drive the car in the next couple of weeks. First time in 9 years. It’s the car my wife and I dated and and hopefully I’ll get to take the kids out on their first ride in it soon. Anyways, back on topic. I appreciate you taking the time to tell me some of the inner workings so I know how it works and how to fix it in the future.

Great story. Hope it works out for you. Nice thing about it, you won't need a blower until October. LOL

 

[moparkrazed]

Switches might be a crap shoot. You might be able to find one at you local parts store or order from Classic Industries. The new switches can be poor quality. ( usually made in China) a used switch might be a better bet but it might be in the same shape yours is. Start a wanted thread and I bet someone will have one for you.

Thanks man. Yeah I wish there were better quality parts available but we will take it as it comes. Good news is I’m no where needing heat in the car yet haha. I’ll look around and might not be a bad idea to get a used and new one to cover the bases if it comes to that. Thanks again for the info I really appreciate any help that’s offered.

 

[moparkrazed]

Great story. Hope it works out for you. Nice thing about it, you won't need a blower until October. LOL

That’s for sure! When I was in high school the heater core went out and had to ride with a rag to wipe the condensation from the inside of the glass to see where I was going. Fun times when you think back... although at the time I didn’t think it was fun at all lol

 

[toolmanmike]

That’s for sure! When I was in high school the heater core went out and had to ride with a rag to wipe the condensation from the inside of the glass to see where I was going. Fun times when you think back... although at the time I didn’t think it was fun at all lol

I think I have a leaking core in my 70 Swinger. My old radiator cap wouldn't hold pressure so I replaced it. Now with all that pressure I have a leak. A little slime on the inside of the windshield and the smell of coolant.

 

[moparkrazed]

I think I have a leaking core in my 70 Swinger. My old radiator cap wouldn't hold pressure so I replaced it. Now with all that pressure I have a leak. A little slime on the inside of the windshield and the smell of coolant.

That sucks man. Coolant has to be the worst smell and having to keep cleaning it. Hope you get it fixed up quick man!

 

[pishta]

Toss in a tube of alumaseal, worked for me. I hear GM called for use of the pellet type (just a disk of this stuff) in their FSM's after some repair.

Dad said they used coarse ground pepper in the old days! the stuff would swell up and plug small leaks.

 

[Dana67Dart]

Put a little grease on the sliding parts

grease intended for electrical switches

That’s for sure! When I was in high school the heater core went out and had to ride with a rag to wipe the condensation from the inside of the glass to see where I was going. Fun times when you think back... although at the time I didn’t think it was fun at all lol

had a 56 Ford PU entire heater unit was removed, used to have to drive with the windows down to keep the windshield from fogging over in the damp winters in So Cal. Going skiing in the local mountains was always an adventure in frostbite!

 

[moparkrazed]

grease intended for electrical switches


had a 56 Ford PU entire heater unit was removed, used to have to drive with the windows down to keep the windshield from fogging over in the damp winters in So Cal. Going skiing in the local mountains was always an adventure in frostbite!

Haha I bet so! In in central South Carolina, winters here arnt too bad considering what others have to through. I’d do horrible or really cold weather lol.

 

[moparkrazed]

Think it’s definitely a switch. Luckily my uncle has one he isn’t using. I blew a fuse, replaced the fuse and blower motor works until I touch the fan setting then blows the fuse again. Thanks for all the help everyone.

 

[cudamark]

Does the switch feel normal? Does it click into each speed setting? If so, I'd check the fuse and connections first before replacing the switch. Those switched are notorious for failing though. The entire power draw of the heater motor runs through that switch (no relay). If the motor get a bit of resistance in it (most of the time it's the bearings starting to seize from lack of lube), the added strain increases the current draw to where the switch will arc and overheat/burn. The bakelite type material where the contacts are will then crumble. Putting in a new switch without fixing the cause, would get you right back where you started eventually......with another bad switch. Make sure the motor turns freely before replacing the switch. If you're not concerned about keeping it stock, you might also consider installing a relay system for it. It's a lot easier on the switch.

 

[moparkrazed]

Does the switch feel normal? Does it click into each speed setting? If so, I'd check the fuse and connections first before replacing the switch. Those switched are notorious for failing though. The entire power draw of the heater motor runs through that switch (no relay). If the motor get a bit of resistance in it (most of the time it's the bearings starting to seize from lack of lube), the added strain increases the current draw to where the switch will arc and overheat/burn. The bakelite type material where the contacts are will then crumble. Putting in a new switch without fixing the cause, would get you right back where you started eventually......with another bad switch. Make sure the motor turns freely before replacing the switch. If you're not concerned about keeping it stock, you might also consider installing a relay system for it. It's a lot easier on the switch.

Thanks for the post. The motor turns great for sure. The fan speed switch definitely is hard to move. The one my uncle has turns freely. After I get the motor to idle for 20 min for a break in I’ll tackle the blower motor prob. Just found out my brand new fuel pump isn’t pumping. But, when it is running the headers sound great haha.