Blower motor switch wiring.

[2ndGenGuy]

So I'm trying to figure out why my blower doesn't work on low. I've got the dash torn apart to look at the wiring. I tested the switch, and all 3 settings on it work just fine. The multimeter shows continuity.

The wiring diagram for hte blower looks like this:

    Fusebox
       |
       |
       |
     Blower
       |
       |
       |
Some Kind of Box
 |     |     |
 |     |     |  <-- Assuming this is low, med, high
 |     |     |
 Blower Switch 
       |
       |
       |
    Ground

When I look under the dash I see the three wires that go to the switch. When the car is on, only two of those wires have 12volts, and those correspond to the "Med" and "High" settings. "Low" has no voltage, and this is why low doesn't work.

But for the life of me, there is no description in the manual of where these three wires go to, or where they come from. I assume that there is a box somewhere under the dash that has 3 resistors that change the resistance on the ground. All I have is the end of them under the dash where it connects to the switch and it goes up into the abyss...

Does anybody have any idea where those 3 wires go to? Where the other end of them is?

[2ndGenGuy]

Search you fucking idiot! If you spent more than 2 minutes looking in the manual, you'd see that theres a box labeled "resistor" in the wiring harness layout diagram. And if you weren't so fucking lazy to not take out the glove box, you'd find the wires lead up behind the blower motor. Think theres a good chance that theres a resistor box back there? Dumbass!

[forrest89sei]

Wow, Um John are you ok?

LOL JK

[2ndGenGuy]

Yeah this is just annoying... Look at this resistor module. Looks like it uses the blower motor to cool these little coils which are just super fucking fragile...



How the fuck do you fix this shit????

[2oodoor]

http://www.autoshop101.com/
go to online instruction, variable resistors
if the coil is broken you will need another resistor block, if the solder is broke at the end, resolder.
Sometimes the blade plug in connecitons on these get hot and start to loose contact ... at the swtich, at the ground for the fan motor, at the block, and junctions in between.
It may be possible to use a block from another type of car though

[2oodoor]

Search you fucking idiot! If you spent more than 2 minutes looking in the manual, you'd see that theres a box labeled "resistor" in the wiring harness layout diagram. And if you weren't so fucking lazy to not take out the glove box, you'd find the wires lead up behind the blower motor. Think theres a good chance that theres a resistor box back there? Dumbass!

a slow noob day, boredom is a bitch aint it, practice practice practice.. lol

[Hazwan]

@ this thread.

Slightly off topic: My blower seems to be slow even at High, so I took multimeter to the blower connector and no matter what speed I put it on I still get 12.something volts Either I tested the wrong wires or theres something wrong with my multimeter lol

[2oodoor]

@ this thread.

Slightly off topic: My blower seems to be slow even at High, so I took multimeter to the blower connector and no matter what speed I put it on I still get 12.something volts Either I tested the wrong wires or theres something wrong with my multimeter lol

You will always get close to battery voltage with a meter at that point, the speed is control by the resistance to ground . The current is controlled so you would measure either amperage or ohms resistance to test it.
I suppose you could measure voltage drop with the meter by disconnecting the battery cable and put the meter in between the cable and the battery.

[2ndGenGuy]

Yeah, all three of the wires will probably read out 12 volts. My multimeter read out 12 volts on both the high and low ends. I bet your fan is getting slow simply due to needing some new oil. The blower is really easy to pull, I'd take it all apart and lube the motor (WD40 or equivalent) and see how it goes. I clean out dirty computer fans and house fans and other fans all the time that way. Helps out tons!

As far as mine go, I picked up some resistors at the store. I was getting 1 ohm across the big resistor, so I picked up some 5 watt, 1.5 and 2.7 ohm resistors to replace the broken one. I'll see which resistor works the best to get the low fan speed setting. Linkage from roodoo was a lifesaver!

[Hazwan]

Thanks! I'll get them checked later

[Civic Accord Honda]

Search you fucking idiot! If you spent more than 2 minutes looking in the manual, you'd see that theres a box labeled "resistor" in the wiring harness layout diagram. And if you weren't so fucking lazy to not take out the glove box, you'd find the wires lead up behind the blower motor. Think theres a good chance that theres a resistor box back there? Dumbass!

..

[2ndGenGuy]

Okay so the fan didn't run AT ALL with the 2.7 ohm resistor. However, with the 1.5 ohm resistor, it ran at JUST the perfect speed. I soldered that fucker in there, and it works great! Thanks for all the help!

So now we know if the low goes out, use a 1.5 ohm, 5 watt resistor. I would be willing to bet that a 1ohm 5 watt resistor would work for medium as well. High just bypasses the entire resistor box completely.

[Hazwan]

Thats good to know. Mine has been replaced with new one by my brother back when he owned the car. IIRC its quite pricey for what seems to be bunch of coils.

Edit: I've been toying with the idea of replacing the switch and resistor with variable resistor like what newer car has. Instead of having 3 speeds, I have like infinite speed selection lol but then its practically useless as I always put them on high.

[Ichiban]

What exactly does the "flow" setting on my hatch do?

[2ndGenGuy]

What exactly does the "flow" setting on my hatch do?

Got me. My 84 has that as well. The closest thing I can figure is that its wired to the VSS and when you're not moving the fan slows down or stops, and when you start going it speeds up just a bit. That's all I can figure anyways... I noticed for sure that it changes speeds, and you can hear one of the fan doors open when you swtich the "flow" setting on or off.

_________________

Here's a pic of my resistor job.

[2oodoor]

Got me. My 84 has that as well. The closest thing I can figure is that its wired to the VSS and when you're not moving the fan slows down or stops, and when you start going it speeds up just a bit. That's all I can figure anyways... I noticed for sure that it changes speeds, and you can hear one of the fan doors open when you swtich the "flow" setting on or off.

_________________

Here's a pic of my resistor job.

glad it works for you, one thing though, those clay resistors will be getting hot. One thing aboujt the bimetal coils is they disipate the heat they generate from the resistance.

Hazwan you may need a transistorized control circuit with IC block on it for something like that, if it is going to last.
(I suppose you could use a large wiper switch type set up like on an electric golf cart which uses a series of resistors fed by a five to eight contact pot switch with a floating brush. Those tend to put off some sparks at times though.).
Unless you can make one (solid state speed control) from a good DIY kit, it may be better to look for an existing control box for that purpose off another type car, then I can get you a schematic on how to wire it up.

[2ndGenGuy]

Yeah I figured it would be fine though, being that's the original reason they put those resistors in the path of the fan. I guess I'll just have to be careful and watch it. I figure it's designed to run without a fan, so it should be good to go in the blower stream.

[Hazwan]

glad it works for you, one thing though, those clay resistors will be getting hot. One thing aboujt the bimetal coils is they disipate the heat they generate from the resistance.

Hazwan you may need a transistorized control circuit with IC block on it for something like that, if it is going to last.
(I suppose you could use a large wiper switch type set up like on an electric golf cart which uses a series of resistors fed by a five to eight contact pot switch with a floating brush. Those tend to put off some sparks at times though.).
Unless you can make one (solid state speed control) from a good DIY kit, it may be better to look for an existing control box for that purpose off another type car, then I can get you a schematic on how to wire it up.

Yeah thats what I thought. I have a friend that is good with electronics that could help me out, but I need to fix my slow blower first!

Whats this "flow" thing? 2g only?

[2ndGenGuy]

Yeah I think the flow thing is 2g only. Never seen it in any other car. Some of the 2geez just have I II III IIII instead of any writing, so I'm not sure which ones got "flow" and which ones didn't. Maybe it was only on cars with A/C?

[Hazwan]

Heh my car already did that with my dying voltage regulator. I have yet to replace them, I'm getting 12.9 something idle without any load.

The battery is dead and I haven't driven the car for 2 months already lol.

[79cord]

Bet my battery is pretty unhealthy by now too, & I should look into my cars lowest fan setting too since it has never worked.

Curious to know how the ventilation compares to the later Accord since I think it's very effective in the 1st gen. while my CR-X is just hopeless by comparison..Needing its fan for any airflow.