AC Blower Resistor Low speed fix (Mod)

[Who]

Well after fixing the low speed setting on my AC several times I took the original fix and modded it a little further. The AC blower fan speeds are controlled through a resistor pack located underneath the glove box in the blower motor housing. The resistor pack has three coiled wire resistors. The low speed setting uses all the resistors in the plug and the smallest of the resistor wires is very thin and frequently breaks. After fixing it several times the wire kept breaking in different places and I decided to fix it for good.
I went to radio crap looking for coiled wire resistors. No luck finding the same resistors on the resistor pack but they did have Wirewound Resistors. A wirewound resistor is basically winding of resistive wire wound around a ceramic rod and encased in a ceramic coat or capsule. Wire wound resistors are designed to be Fireproof and have a operating temp between -55C/+255C according to the packaging. Fireproof is good in my opinion. The Radio crap website states different thermal temps but I believe it to be wrong.
I believe the ohm rating on the original resistor wire is about 1 ohm. Radio crap carried a 1 ohm resistor but it was quite large. I picked the 0.47 ohm (271-130) resistor. It's very small in size and would fit in nicely. I cut out the old wire and soldered in my new wirewound resistor and shazam, low speed working again. The low speed setting is not as low as it used to be due to the small 0.47ohm resistor but it is still quieter than the med speed and the auto fan speed feature works again. Special note: Do not test the fix without having the resistor pack in the blower housing.

Dealer price for Blower Resistor $44.00
Wirewound Resistor fix $1.69
Priceless

Any opinions would be appreciated especially if someone thinks I going to burn the house down.

 

[jacques]

i don't know enough about this to offer 'safety' input, but it seems like a great cheap fix! i, for one, will be trying this a bit later on. thanks for pioneering!

 

[KeithH]

Not using the regular dealer for parts - even more priceless...

Contact Champion or Elmhurst and get a pretty decent discount on that part.

 

[jetjock]

^ Gotta agree with that. It's no wonder many owners whine about prior ones.

That's a 5 watter. I'm gonna say, based on a rough guess of blower current and Mr Ohm's law, it'll be OK as long as it stays cool. Myself, I would have stuck with nichrome...

 

[Kckazdude]

Will our blower motor, at low speed, be enough to keep that cool? I am just not used to seeing it in this application.

 

[jetjock]

Makes you wonder eh? It should also make you wonder what the root cause of his blowing the low speed coil all those times was

 

[Kckazdude]

^^I wasnt even going to go there.

 

[Zumtizzle]

:rofl:

There's outside of dealer options too. Hell even AC Delco makes a resistor for our car. (Corolla/Geo Prisms use this resistor too.)

 

[GrimJack]

The new unit from the dealer is considerably more robust than the original one. My original lasted a good 15+ years, I suspect my replacement will last at least double that.

 

[Justin]

:rofl:

There's outside of dealer options too. Hell even AC Delco makes a resistor for our car. (Corolla/Geo Prisms use this resistor too.)

Got a part number handy? (if not i'll call 'em monday)

 

[theKnifeArtist]

i was gonna do try this same kind of mod, but i was just worried about the cooling of the resistor, since it's not exposed to the air flow. is it safe?>

 

[Kckazdude]

I wouldnt think there isnt enough air flow to keep the ceramic resistor cool. That is why manufacturers use open coils that are mounted in the air flow. Also if you are burning the resistor repeatedly, as JJ aluded to earlier, check your blower motor itself. Usually what has happened is the motor isnt turning as freely.

 

[Who]

^^^ I would say 20 yrs of age and condensation (corrosion). The factory low speed resistor wire was very brittle.

OK, you guys are shaming me into going out and fixing right. :slap:

 

[theKnifeArtist]

yeah but that 20 year old blower could draw some excessive amprege too

 

[Zumtizzle]

Got a part number handy? (if not i'll call 'em monday)

AC-Delco PN: E1145A

 

[Justin]

AC-Delco PN: E1145A

Thank you sir.

I'll counter that, with this!


http://www.rockauto.com/catalog/raframecatalog.php?catalog=301&partnum=E1145A&a=FR301-E1145A


27 bucks for the correct fix.

 

[Who]

^ Gotta agree with that. It's no wonder many owners whine about prior ones.

That's a 5 watter. I'm gonna say, based on a rough guess of blower current and Mr Ohm's law, it'll be OK as long as it stays cool. Myself, I would have stuck with nichrome...

Nickel Chrome resistance wire. Oh my _od!! We use nickel chrome wire at work to cut Styrofoam blocks for mold pours. The wire gauge is just about right as well. Kudos jetjock!

----------------------------

I was able to get some nickel chromium resistor wire. I removed the wirewound ceramic resistor. I cut a length of the nickchrome wire to measure 1 ohm of resistance and coiled it up and soldered it on. Looks like the factory original now.

Thanks all for your input.

 

[NiGMa]

Nickel Chrome resistance wire. Oh my _od!! We use nickel chrome wire at work to cut Styrofoam blocks for mold pours. The wire gauge is just about right as well. Kudos jetjock!

----------------------------

I was able to get some nickel chromium resistor wire. I removed the wirewound ceramic resistor. I cut a length of the nickchrome wire to measure 1 ohm of resistance and coiled it up and soldered it on. Looks like the factory original now.

Thanks all for your input.

Thanks!!!!

This worked for me also! I bought some Nichome 80 wire, which was 13.4 ohms a meter, so cut a 7.5cm section and soldered it in, worked great! =)

Thanks again JJ, what do you think of my problem in this thread?:
http://www.supramania.com/forums/showthread.php?t=92520

 

[tissimo]

Neat idea, but I'd just use the oem, its not that expensive. Its still going strong in my car.. though with the FL sun it doesn't run low very much (only at night).

I wish they redesinged our A/C system like the celicas system, its MUCH nicer.

 

[jetjock]

Thread from the dead eh? I mentioned nichrome because it (or a similar alloy) is what the OEM resistor uses. That said, although I applaud the ingenuity shown, I have to agree with tissimo.

NiGMa: I'm afraid I can't be of help because that climate panel isn't used on USDM cars and I'm unfamiliar with it. Sounds like the transistor could be the problem though, at least with the lighting part. Consider yourself lucky: our system is even more complicated.