Blower motor resistor question...

[slycer2002]

I have been having problems similar to ones I've seen in the forums here where my blower motor is very sporadic. Sometimes it works, sometimes it comes and goes, and other times it won't come on at all. After reading some of the threads here, I figured that either the plug, the resistor, or both, were pretty much corroded. When I got the old resistor off, the coils were in decent shape, the plug on the resistor was fine, and the plug on the pigtail was fine. I really didn't see much corrosion, and the metal even still had some gleam to it. Not bad for a 17 year old resistor!
Now, here's the part that I'm having issues with. When I was actually pulling the resistor out of the box, I noticed some type of finned device inside. What is this? Is this the heater core, or something else? The reason I ask is because ALSO inside the box was all kinds of old dead leaves and maple tree helicopters, and who knows what else. Is there an easy way to open the box and get all of that stuff out of there, and better yet, how did that stuff get up in there in the first place? That's the part that has me completely baffled!
On a side note, I went ahead and put the new blower motor resistor in and plugged it up, and there was no change in the blower motor. It still came and go as it pleased. I noticed that when I rev the engine a bit, the blower will come on almost full blast, and then slowly die off. Any help on this would be greatly appreciated. Thanks in advance.

 

[rusty ol ranger]

A finned device? Like a mini radiator???

Thats your heater core bud

later,
Dustin

 

[slycer2002]

That's what I thought, too, but my heater hoses don't go into this box. They go right into the firewall. That's what had me confused.

 

[Jorley]

Most likely your A/C evaporator coil.

 

[4x4junkie]

Most likely your A/C evaporator coil.

Yep. A/C coil.

The leaves get in there through the cowl vents or around the openings for the wipers. Stick a piece of ¾- 1" tubing on the end of your shop vac hose (seal it up with some duct tape) and stick that through the hole to get the leaves out.

 

[RobbieD]

Yeah, do get those leaves out, following 4X4junkie's advice. Not a good thing, especially if they catch fire.

But you did do good thinking about and checking for corrosion on the resistor plug. That's usually where it occurs, and would cause the intermitent blower operation you're experiencing. At this point, there is another place to check for your problem, if you want to, and that's to pull the heat-AC control head, and check for overheated terminals there.

I've seen the control head overheating mainly in Ford vans, not Rangers, but it could possibly be the cause of your interment blower problem. Might be worth checking, and good luck with getting to the bottom of the problem.

 

[Mark_88]

You can also get at them from inside the cab...like when you change the heater rad core...but that would require taking things out...

You might want to invest a bit of time/money into a grid cover for the air vent...like a pinhole type screen (or just a mesh screen) to keep that stuff out and let the water run off...I actually plugged my old one up when the firewall was leaking by just screwing on some sheet metal...but that was mostly to keep the water out...

 

[slycer2002]

Okay, thanks for all of the suggestions. Its supposed to be warmer this weekend, ( currently 23 degrees and dropping), so I'll probably tackle this again then. Luckily, my wife and I have another car we can drive in the meantime. Thanks again. I'll let you all know what I figure out when I get a chance.

 

[MoonDoggie]

RE: Leaves in the heater core

I actually had tree leaves inside the heater core next to the heater blower motor relay resistor. The relay resistor coils got red hot and set the leaves on fire...smoke everywhere in the cab. Fortunately the blower motor relay which controls the blower speeds blew most of the resistor coils so that only the high speed worked. In the Tech Library section is an article on how to change the blower motor resistor. But when you do, be sure to use a strong vacuum to suck out all the debri, leaves, etc. next to the heater core. It's really tight in there but I was able to tape successively smaller hoses to my outdoor vac and suck it clean.... good luck.

 

[slycer2002]

Okay, almost two months later, and I figured I should probably update this thread. The blower motor problem has been solved. Turns out all I needed was a new blower motor. $20 at AdvanceAuto, and I was back in business. Thank you to all who helped. It is most appreciated.

 

[RobbieD]

Glad to hear you got it sorted out, especially for a reasonable cost. And thanks for letting us know how it turned out.