Heater / ventilation fan / blower question (1 Viewer)

[Wellcraft19]

Have not been on the forum for a long time. Don't even want to know what I've been missing out (but will later tell what happened when my wife backed into my 100 with her Element in February...).

In any case, for some time now, the heater fan is stuck on "high", or off. It does not matter what combination the controls are in. It either runs "full blast" or not at all (when it should be "off", so that part is OK).
And, yes it is a '99 100 with the "manual" climate controls.

In auto mode, the green LED does move from the different fan speeds, but the fan still runs high. Same if using A/C, auto, auto fan, any temperature, or any combination thereof.

Does the 100 have a resistor as for the various fan speeds (like the older models), or is it electronically managed (obviously the "control" is fully electronic and seem to work). And if resistoer, where is it located?

I have taken the heater controls apart and re-assembled it again w/o any difference.

Thnx /// Per-Ola

 

[NMuzj100]

I know I've seen this problem on the board before but don't remember the resolution.

Have you done the climate control system self check ?

The A/C panel can do a self diagnosis. DI-620

1. Turn ignition switch to on while holding down the A/C and Recirc/Fresh switches.
2. All the indicators should flash on and off at 1 second intervals.
3. Any malfunction will be indicated by the trouble area's light blinking. A table to translate the lights to a trouble spot is on DI-624 or post it here and I'll look it up.​

 

[Wellcraft19]

Interesting, thanks for the quick reply.
Did search the forum first before posting, but only found an older post regarding the 90 series and broken resistor:
https://forum.ih8mud.com/79-95-toyota-truck-tech/192996-heater-ac-fan-blower-question.html

Just came back home and did the system self check. All lights come on, and then after a while are left blinking the following ones:
- Rear defroster
- Front defroster (on the air distribition selector)
- The outside temperature on the little LCD display

Sort of weird, guess I expected something with the fan.
If you have a chance, it would be greatly appreciated if you could look up the error code for this.

 

[raydouble]

I would say part of the blower motor resistor is burned out.

 

[Wellcraft19]

Update, and I guess I have to check this tomorrow, outside again, a tad dark in the garage.

Did look in these two posts, with great info from NMuzj100:
https://forum.ih8mud.com/100-series-cruisers/66870-new-2000-lc-has-issues-help.html
https://forum.ih8mud.com/100-series-cruisers/121535-automatic-headlights.html

Turns out I indeed had stuff on the dash (two small magnetic "stickers" that had positioned themselves over the DS (left side) sensor, and a piece of paper over the PS (right side) sensor.

However, it did not change any of the error codes, which as per the post above is SOLAR SENSOR malfunction.

Any idea what if any indication the flashing outside temp indicator might have?

And when hitting the rear defrost button, the entire control unit goes back to "normal" (just like turning off ignition and turning it back on). No other button has any "impact" when in this diagnostics mode.

 

[raydouble]

The speed looks to be controlled through a relay? Not a typical resistor.

Looks like there is also a separate blower motor controller that controls front and rear?

 

[Wellcraft19]

Thnx!
Fluke will come out tomorrow morning for checking those voltages. Perfect for a rainy Saturday!

 

[raydouble]

Thnx!
Fluke will come out tomorrow morning for checking those voltages. Perfect for a rainy Saturday!

Good luck

If you need anything else let me know, damn electrical manual for this thing is like 450 pages long.

 

[100 TD]

You may be able to pop the cover off the relay.........I expect it's full of resistors which have blown or shorted out, you may be able to fix or just buy a new one depending on price.
Any pics would be good!

 

[uHu]

In any case, for some time now, the heater fan is stuck on "high", or off. It does not matter what combination the controls are in. It either runs "full blast" or not at all (when it should be "off", so that part is OK).
And, yes it is a '99 100 with the "manual" climate controls.

In auto mode, the green LED does move from the different fan speeds, but the fan still runs high. Same if using A/C, auto, auto fan, any temperature, or any combination thereof.
Thnx /// Per-Ola

I had the same symptoms when the car was new. The problem was that the dealer had disconnected the plug to an ECU which is in the dash in the radio area, when installing the radio/CD.

 

[Wellcraft19]

Blower problem solved - photos are coming

Problem solved! Thanks to everyone who commented and especially raydouble and NMuzj100 for the test procedures.
(pictures will be coming tomorrow)

I located the "blower motor control relay" in the PS footwell, in front of the fan motor. "Relay" is a misnomer since it is not a relay but the actual the "speed controller" (not with resistors though, but a thyristor type electronic voltage regulator) for the blower motor.

I did the tests as per raydouble. Everything was fine until testing "4-5" under the three different conditions (still with the blower stuck on high...). I got the following voltages:
0.057V (rec. 3.6V)
0.025V (rec. 8.3V)
0.011V (rec. 13.0V)

Pulled the "relay" and took it apart (photos coming). It is an assembly with most likely a thyristor, one small and three large electrolytic capacitors on a printed circuit board mounted on a heat sink (heat sink is cooled by the airflow from the fan it control - smart!). Everything is protected against humidity by a "gooey", almost "runny" clear coat (still VERY flexible after now 10 years...). I could not see the specs on the capacitors the way they were soldered in, but they look to be either 60µF or 80µF (105C rating).
Nice design that "looks" expensive.

Plugged it back in and did tests again. Same results/voltages. I pushed the probe in a tad harder on cable 4 (a thin white/red one) and suddenly noticed the blower speed go down to setting as per the dash speed selector (low). I also got voltage readings fairly close to the test recommended ones.

The blower "relay" is an electronic voltage regulator with leads 3 and 5 being the supply voltage, leads 1 and 2 being the output to the blower motor and lead 4 being the "poke", hence the electric signal that triggers the thyristor to regulate the output to the fan.

Suspicion, bad connection (somewhere). I did jiggle a bit and could often get the fan to suddenly speed up again to "full" (happens when the control voltage on lead 4 disappears). Was it a broken cable, bad connector, or a bad connector inside the "relay"? Did work them all by taking the connector apart (tricky until you found the "key"), running continuity check on the wire and wire to "relay", all while moving the wire around. All OK so I decided to mount it all back together again. It works! (all speed settings, as well as both "auto" settings, or any combo thereof).

Not in the Toyota test, but I'm also listing the voltage seen between "ground" and "cable 4" in all 5 fan speed selector settings:
Off - 0.0V
Low - 0.0119V
M1 - 0.009V
M2 - 0.002V
Hi - 0.030V

BTW, I did run the "climate control system self check" before starting the work, and sure enough, with a clean dash and the car in the sun, "SOLAR SENSOR malfunction" error code was gone. I still however have one, and would appreciate if NMuzj100 or someone could look it up:
- Blinking rear defroster and blinking "on/off" switch to rear cabin blower + blinking outside temp in the LCD display.

This code was there before fixing the blower, and it is still there. Probably not critical, but my curious mind wants to know.

Information on the sticker for the "Control, Blower Motor"
87165-22050
499300-1060
12V
Denso Japan

And, lesson learned; a little bit of work prevented replacement of a perfectly good "blower controller relay".

Still a mystery is why I do not have any voltage in the cable that goes to the glove box light, but I did not have that last year and guess I can live w/o it.

Thnx /// Per-Ola
(pictures added today)

 

[raydouble]

Always nice when you don't have to buy anything.

 

[Wellcraft19]

Yup, especially since this little "blower control" is about $250...

And NMuzj100, if you have any insight on that last error code...

 

[NMuzj100]

Blinking "RrDEF" (Rear window defogger switch indicator light) and blinking "RrACSW" (Rear A/C ON-OFF switch indicator light) together = Normal operation.

 

[Wellcraft19]

THNX!
Was far too easy - didn't really think I had any problems, but code triggered my curiosity.

 

[LXinOBX]

Hi all.

I am stumped and am hoping someone might be able to provide me with some ideas as to what is going on w the fan speed blower on my '98 LX.

What I do know(I think anyway):

1- The blower runs at one "low" speed regardless of LCD display - which will show partial to full bars as fan speed button is pressed. Turns off when "off" button selected.
2- Voltage at the fan blower connector shows 12v regardless of position (yet the blower runs "slow") - you would think it would display the "my fan only runs a hi speed" symptoms.
3 - I have purchased and installed a new Blower Controller - same symptoms whether the new or old is installed
4 - Diagnostics (AC and Recirc depressed) - come back as 00 - all good.
5 - Fan Blower assy has been removed and checked for obstructions, chamber vacuumed out. When bench tested seems to run at speed (tested w a 1A charger).
6 - Cabin filters have been removed and cleaned.

Thanks in advance to anyone that might provide some additional advice - one thought I had was the AC Amplifier - does anyone know if these symptoms might point to it (I would think the diagnostics would identify same?)?

Thanks so much,

Bill

 

[LXinOBX]

Update - when I connect the Blower directly to the battery, I get a "full on" fan speed, so the 12v feed from the blower motor controller, although 12v, must not have sufficient amperage to drive the blower anything above a "lo setting".

Any thoughts?

Again, thank you.

 

[options2]

Blinking "RrDEF" (Rear window defogger switch indicator light) and blinking "RrACSW" (Rear A/C ON-OFF switch indicator light) together = Normal operation.

I just tested mine after I read this as I had an issue with it over the weekend. Where do you pull the error codes from? I guess I need to break down and get the right manual for my year.

Code after diag:

outside temp, rear ac, recirc = blink 1
outside temp, rear ac, fan speed 2 = blink 2
outside temp, rear ac, feet = blink 3
outside temp, rear ac, face = blink 4
outside temp, rear ac, fan speed 4 = blink 5

then it repeats over and over.........

 

[LXinOBX]

At least w my truck (LX) the lights flash and then stop - there is a numeric value that is then visible in the screen - that is the code. If you push the recirc button again the system then goes through all the different hvac functions (except in my case as the fan speed [indicated] increases nothing actually happens with the [actual] fan speed) until you touch fan "off".

 

[options2]

At least w my truck (LX) the lights flash and then stop - there is a numeric value that is then visible in the screen - that is the code. If you push the recirc button again the system then goes through all the different hvac functions (except in my case as the fan speed [indicated] increases nothing actually happens with the [actual] fan speed) until you touch fan "off".

Mine lights all flashed for awhile then stopped, then it started with the sequence I listed above. No numeric code on the screen.

My 100 is also a 99 with the manual controls.