Hello -

I have a 1999 Camry with a fan motor problem. The motor won't run in the
low and next to low settings. The 3rd setting (next to high) and high settings
were working OK; untill this morning. I noticed the next to high setting quit
working as well. I now only have the high setting. To be clear, its the fan
motor for the heat and a/c settings. Any help in dianosing this problem would
be greatly appreciated.

Thanks!!
Al

 

Most likely the blower motor resistor pack is blown. This is part of the fan speed control circuit. For low and medium speeds a resistor is placed into the 12V power wire to the blower to lower voltage and thus speed.

Find the air control box above the air blower (looks round) under the passengers side of the lower dash. Look for Blue/Black, Blue/Orange, Black/White and White/Black wires running to a plug on the side of the air control box. The resistor pack is inside the box but wire plug into from outside.

Remove the plug then take out the screws holding the resistor pack in. Easy job to replace. Autoparts stores and the dealer should have the part.

It looks like the part at the link below:

http://www.rockauto.com/catalog/moreinfo.php?pk=445216

 

That's the fix. 99's must have had a bad batch. Mine went several years ago, my other Gen 4 is older but has had no problem. The clue is the high setting bypasses the resistor and will work despite the resistor being toast. It is little bit of a PIMA getting to the fasteners but not that hard. Use a good light.

 

My fan issues are a little different. When I hit a bump, fan cuts off, regardless of setting. Once I hit another good bump, comes back on.

I disassembled fan switch and cleaned the contacts, which had only minor oxidation/green build up at the contact points.

After reassembly, I test drove with blower motor resistor connected and again with it disconnected. On both test drives, mysterious bump fan cutoff still occurs.

Could this be a relay issue in my case, or is this still definitely a blower motor resistor fault?

Thanks in advance for any insight...

 

The heater relay solenoid is powered by a 10A heater fuse. This solenoid is controlled by the blower motor speed switch. The relay solenoid is powered when any blower speed is selected.

The heater blower motor receives power controlled by this relay. This relay receives blower motor power from a 50A fusible link.

Blower motor power from the relay then flows to the motor. Then from the motor to the blower motor speed switch. If high speed is selected the power flows to ground.

If a lower speed is selected, power flows through the resister pack then to ground.

At max blower speed the resistor pack is bypassed.

The heater relay is inside a long, narrow plastic box on the drivers side of engine compartment.

10A heater fuse in the fuse box behind the ash tray on the lower dash near where the the drivers left knee would be.

50A heater fusible link. May be in a small box, front of engine compartment, passengers side of radiator or in the box in front of the heater relay box. The box may contain a 100A Alt fuse, make sure you have the right one. Check the fuse for good contacts at each end and lack of corrosion. It is possible the fuse can become damaged resulting in an intermediate contact.

When doing your diagnostics, try to determine if DC power to the blower motor is being cut off, or the ground for the motor is going bad.

A lack of power or a bad ground will cause the motor to stop running.

Might make a diagram. Just note, the switch and resistor pack are after the motor in the power circuit, not before.

 

Joey, that's pretty much the tack I was going to take tomorrow morning. I'll be underhood anyway replacing the passenger-side radiator fan. Electrical troubleshooting is not my forte, so I appreciate greatly your taking the time to suggest a plan of attack. Will report back with my results tomorrow evening.

OAN, this car simply won't die. 158k and still runs like a top; this HVAC malady (and the cracked radiator fan) are the first troubles I've had. (Mine is a J-VIN model, by chance, not by intention.) I'd love to experience that new car smell again, but it may be a few more years before that happens, judging by the first decade of its life thus far.

 

Hang in there. If the car is taken car of, it will last as long as you need.

The cracked radiator is very common. A product of using plastic, heat and pressure cycles.

The radiator fan and blower issue not common. The resistor pack can fail though.

 

Actually, Joey, in a sick kind of way, this is fun for me. I like solving problems, and miss the 'tinkering' I had to do back in my HS and college days.

Looks like all the relays are in the front box by the battery. I'll search for test specs on these after I post this message:
Fan 1: ISO B4-S
Fan 2: 12U-10
Fan 3: 12u-14

Bobby

 

Just found this during search:

http://www.camrystuff.com/manuals/Ge...Electrical.pdf

Now commencing testing...

RDS

 

Fuses/Relays/Motor Blower Resistor all tested good.
While picking up the radiator fan at the parts desk, one of the techs happened to be there and recommended looking at the fan motor itself, based on my description of the symptoms. Says contacts/brushes in the fan are probably worn. I've seen this procedure outlined in other threads, and this may be more than I can handle, so looks like I'm going to cry uncle and pony up the $$ to have dealer replace it next week.

Thanks again for your help, Joey.

Bobby