Dear Mitsubishi Diamante community:

I am new here in this prestigious forum, and from an advice of a friend of mine I subscribe myself to this community.

My 1992 Diamante, 4 doors, 6 cylinders, 3000 DOHC engine, 126000 miles, present the following malfunction in the A/C blower:

The blower switch function erratically: some times works normal once you turn it on, other times does not power the blower, although the compressor is
running and then, if I move the blower switch to the highest speed position, it starts but you can not move it into a slower speed because it stops blowing air.

Then you leave the blower functioning in high speed for a 10, 20 minutes or more and you try again a lower speed, then it work with this lower speed. The same thing, let say I park the car, stop the engine and left the switch in the low speed because it was working fine for the whole trip, I start the car and nothing happen, I have to move again the switch to the highest speed position, and all over again

If somebody in this forum could help me, I will be more than happy. THANKS!

the may be a fan (edit resistor ) near the internal fan motor

that needs looking at for a broken wire coil

Dear Chain Rattle:

Thank you very much for answering my thread. One question top you and to all this Mitsubishi community. Can you tell me where this relay is located and/or can you tell me where I can find/download a print layout of this problem I am presenting here? Finally, can you tell me how tio gain access to that particular relay and possible broken cable?

In advanced, thank you very much to you all

Marvic

Actually i think he is referring to is the Blower Motor Resistor , it is not actually a relay. But a coiled lead bank that diverts and resists the power ampage to control the blower motor speeds via input of the blower control switch.

It is located in the case near the blower fan , retained by 2 retaining screws.

Did that resistor thing fix it? I have a similar prblem. While driving the blower just stopped. The display showed the fan was still on and the compressor still works. I checked the fuses and all were good. I have replaced my control unit( the thing with the display and buttons) and still doesn't work. I know my blower is good cause when the relay is grounded the blower turns. I had a mechenic look at it and he thought it was the control unit so that is why we replaced it. He had an A/C colligue tell him that it could be the transitor that not letting the control voltage pass through. He called the Mitsubishi parts dept and they said they had only sold one of them since he had been there( a Long Time)
My car is a 1999 Diamante LS with the auto/ digital environmental control unit.

Any Idea's?

Thx in advance.
Joe

HI there Joe, does yur fan work on any setting? Like high? But the blower resistor can be the issue , unlike the older models tho because this one uses a completely diffrent a/c control unit. I had this happen on just 2 people with yur type of a/c control head and it was the case mounted blower motor resistor. Others do not use this type some 98 and up models.

The fans speed is controlled via the electronic climate unit and the power relay. But the voltage is resisted, the mototr may turn on general grounding or checking applications , but , when on the system it is requiring higher than the set required voltage. The fan can be bad and still work is wut i am saying. Ive seen it in my system. Its fully digital screen and similar to the 99 up models. There is a "power ground" or logic ground per say, this aids in doing away with the blower resister on these type of systems with the digital climate control.

The blower is nominally in good working order is set to work between certain low power voltages. When and if the blower starts to get bad it will require alot more voltage than normally to operate it. This is why it would not work on the car , but would when testing it yurself.

When supplied a good bit of ground or voltage away frum the regulated set up it will work . But its made to work within a low voltage setup.

Hi KiT, My fan does not work on any setting. There is a blck box in the case mount that I was told is the transistor for the blower motor. Is there any way to tell where the problem is? I am an Electronics Tech and have access to many electronic TE. Is there a way to eleminate the ECU, Transistor, Blower? I have already Spent $150 bucks on troubleshooting. Is there a Troubleshooting guide that will tell me what the outputs at differentpoints are supposed to be?

I live in Florida and the car is black so it is very painfull to drive.

With the blower motor resitstor there is no way to eliminate it , onlee thing is to replace it. The blower resistor is a sinced heated resistor element , as is why its mounted in the airbox after stream of air after the blower itself

Thanks Again KiT. Do you know how I can check the output of the ECU to eleminate it from the equation? Also, How can I tell if the blower is bad or Good? You are a great help on this issue. Are you a Mitsubishi Tech?

If yu have teh blower that uses teh blower motor resistor , there is no way to go around it. The resistor is there for the specific reason of controling teh fan speed , without a large amount of voltage going to the a/c main fan control switch. so the blower resistor sits conveniently near the blower itself and is operated by the fan switch. The heat sincs on the side of the side of the resistor thatsits inside teh case do get pretty hot while the blower is in operation, so caution of attempting to touch it with power going to it. Its a fairly small item tho , not that large as yu may be expecting

I will look at the suspected resistor and see if I can get a part number. The thing that the mechenic said was the resistor was a black rectangle box about 3" long and 2" wide and tall. He said it was solid state and there isno way to test it. I would just like to know if it is bad before I spend the 60 dollars on it to replace it. I will try and get a picture of it and post my setup.

Indeed there is no way to test it, it is not long , and is rectangular in shape. It is basically a resisted heat sinc of sorts. Just be lucky yu dont have my climate control system. The one i explained earlier in explained detail. Mine uses a "Logic Power Ground"

Lots of moister in the evaporator core case usually causes the blower resistor to go in these models and 96-2005 Asian Market/99 up Galants and Diamate's . Sumtimes by a slightly plugged evap case drain , or heater core line seal leak

I found a pic of the ECU I have if that helps in this trouble shooting.
Here is the link url. i don't know how to insert a hyperlink:

http://img523.imageshack.us/img523/8669/img1830bw5.jpg

I just removed the resistor/ transistor. Its part number is mr460293. I assume this is what you are talking about? Also the manual I have says to check the blower motor relay. I checked that and it seemed good, but I am not possitive. With voltage applied there was continuity between pin 2 and 5 but the manual said check it between 2 and 4. THere was no terminal in the 4 location like the manual said. only a little dot but I could not get anything from that one. According to the manual everything is good. Only it doesn't say anything about the power transistor except how to remove it. I am at a loss. IS it the relay or the power transistor? Anymore Ideas?

Yu may be accidentally checking the A/C condensor relay and not the blower fan relay. I will incorporate pictures . But the A/C condensor relay incorporates the use of terminal 5 not the blower relay . The A/C blower relay uses a 5 Terminal in case of my unit and sum Verda models with a full Digital Touch climate control.

But on standard Diamante and most Magna models , i will put up schematics. Hopefully they will help. Like i say there is no way to test the blower resistor. On models with manual fan controls and most digital blower controls , when the resistor is bad the blower usually works on the highest setting, but not in all cases tho. there are exceptions.

I used that schematic and my diamante is the same as the 3rd gen verada. The relay I checked is on the block that has interior fuse panel. The Relay looks like the one in the picture but there are only four terminals on it. The one oposite 2 looks like it is terminal five per the schematic and there was voltage between the two. Also, resistance between 1 and 3 was around 300-400 ohms. Is that normal to be that High? According the diagram the spot where I was checking was connector B-83. Also, Mine does not have a resistor. It is a power transistor. It has a three terminal connector on it.

The relay click when I had