I think my amazing 2011 Fit Sport (115K miles) appears to have the “HVAC only works at setting 4” problem: the fan only blows at 4; the air isn’t very cool most of the time but occasionally gets nicely cool at highway speeds - but it doesn’t happen every time.

The cost of HVAC diagnostics+parts+labor is a lot right now, so I’m considering replacing the blower motor and resistor myself. I renovated a house largely by myself but this would be my first car repair and I’m nervous.

Does this sound like the usual blower motor/replacement problem? I can’t find any
information on whether the AC is usually cold if the only thing wrong is the blower motor/resistor. FWIW, the current oil change code includes a request to replace the engine coolant.

 

Your fan symptoms do sound like an issue with the resistor. I had the same problem last summer.
I replaced both the resistor and blower motor at that time after reading (here?) that problems with the blower motor are the most likely reason for the resistor to go bad. I found good prices on generic versions on Amazon so it made sense to replace both parts. If you haven't replaced the cabin air filter you should do it at the same time.

DIY replacement is not difficult as long as you have the required flexibility. The basic procedure is that you squeeze your upper body into the passenger floorboard, unclick a couple wires, and undo about five screws. You can then remove the resistor and blower motor. Reverse that procedure and you're done. If you set aside the somewhat tight work area it's one of the easier DIY jobs you can do on a car and certainly less difficult than some of the work you would do when renovating a house. There are plenty of posts here detailing the procedure, plus you can always find Youtube videos.

When your A/C is working correctly you should get cool air regardless of the fan position (obviously more cool air on high fan); if it's intermittent or sometimes not getting cold at all I think you have a separate issue to deal with. For a 10+ year old car, it's possible that your A/C system needs a recharge.

Most of the maintenance minder lights are "dumb" in that they are triggered by mileage. The oil change life counter also uses some metrics from your driving style and conditions. I doubt that the coolant change has anything to do with you A/C issues.

 

At the bottom of the page here on your post, is a list of "Related Topics"- kind of a poor man's search feature. Read some of those posts to familiarize yourself with the blower motor and resistor issue.

 

@Drew21 nailed it. two issues going on. the resistor controls blower speeds, a relay would address a won't turn on/won't turn off fault, a blower motor could present won't turn on or could function normally but be noisy, a cabin air filter would present as reduced flow/moldy sour air (which leads to blower motor failure), a refrigerant leak would present as poor or no cooling capability. there's also other faults, but the above is the common woes.
Good news! if your ac still gets kinda cold your system can still work :}

@56chevydan is spot on regarding usage of related topics listed at the bottom. as with many forums, searching on google is usually more beneficial than trying to search within the actual relevant site. those links can help a lot.

Unlike construction/renovation, there's a book for your exact car that covers everything shy of structural repair/bodywork. The shop service manual should still be linked on this forum. I'll say that having access to such a book (and the quality of it) is a qualifier I use for vehicle purchases. which is to say: I wont likely buy another modern-ish toyota.

After replacing the resistor and, should you choose to do so, the blower, you should take your car to a shop to address the poor cooling performance. They can pressurize the system, find the leak, get the air and nonsense out of it and fill it with freon and pag oil. it may cost a couple hundred bucks if they have to replace a component, but if they're just charging it, $100 bucks will do yuh. If you should need to replace a leaky a/c condenser, come back here and do that yourself. You can get good prices from rockauto and even do a search for an up-to-date 5% coupon code provided to car forums (I think ours is outdated.)

There's also a write-up on here for adding a metal mesh into the front bumper to better protect the condenser from rocks and debris. It was one of my first mods and I'm so stoked about it because it's not noticable and really works. Lotsa modern cars (particularly those in budget) don't do much anything to protect the delicate condensers they house.

😂 I've got a reno question or two if you're up for a little tit-for-tat.
​​​​​​