Resolved 2GNT AC issue (blower motor and AC light turn off simultaneously and blow fuse)

[96WhiteEclipse]

Hey guys, recently my cars AC has been acting funny. I was driving and all the sudden my blower motor stopped blowing air and the AC light turned off. This happened simultaneously. I checked my fuses and I blew the 10A “heater relay” fuse on the inside of the vehicle. I replaced the fuse and my AC light turned on, however the blower motor wasn’t running.

I turned the fan control knob through the positions and it would run in some positions but not all and it was overall just being very odd. On the highest fan setting it wouldn’t run but when I grabbed the knob and wiggled it around the blower motor would come back on. I finally got the blower motor to stay on max fan speed while the knob was taken off of the climate control unit. However it shortly blew the fuse again. Also if this would help when I got the blower motor to run I would hear the compressor kick on it would blow cold air.

What could be causing this issue? Do I need a new climate control unit? Is there anyways to replace the unit or diagnose the issue without pulling the dash?

 

[99dsmer4g63]

I’d probably take a peek at the resistor for the blower motor first. I'd pull the blower motor and make sure there’s nothing in the cage or anything broke.

-Daniel

 

[96WhiteEclipse]

I’d probably take a peek at the resistor for the blower motor first. I'd pull the blower motor and make sure there’s nothing in the cage or anything broke.

-Daniel

Where is the blower motor resistor located?

 

[99dsmer4g63]

Should be close to the blower motor on the hvac box

-Daniel

 

[96WhiteEclipse]

got to the resistor, but I’m not sure which pins to test for resistance. There’s 4 pins but I don’t know which is 1,2,3,4

 

[steve]

Do you have a copy of the FSM? If not check out the Resources Section of the forum.

Articles: Manuals & Documents

Manuals and literature from Mitsubishi/Diamond Star Motors.

www.dsmtuners.com

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[96WhiteEclipse]

Do you have a copy of the FSM? If not check out the Resources Section of the forum.

Articles: Manuals & Documents

Manuals and literature from Mitsubishi/Diamond Star Motors.

www.dsmtuners.com

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I’ve got the Hanes manual and I just downloaded the factory service manual. I’m still not great at understanding how to read electrical diagrams I did my best at testing the resistances across the pins and I didn’t get any numbers that were wildly high indicating infinite resistance. I would get around .8 ohms - 2ohms depending on the pin so it leads me to believe it’s not the resistor. I really think it’s the fan switch because it’s finicky about the position and when I wiggle the fan control knob the blower works and then doesn’t and then blows a fuse. As well that fan knob gets turned a bunch of times so it would make sense for it to wear out. However I have no way of proving it without pulling the dash and probably just shotgunning a part. What do you think?

 

[luv2rallye]

Here's some pics of a bad and new blower resistor (and where it is - middle of that pic) which should help.

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[96WhiteEclipse]

Here's some pics of a bad and new blower resistor (and where it is - middle of that pic) which should help.

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Replaced the resistor and it’s still blowing fuses acting the same. I pulled the dash and here’s what I found. The connector is toasted. I’ve got a new (new to me) hvac control unit on the way. Do you know what the name of this connector is or where I could find one?

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[19Eclipse90]

Try this: Sheridan Engineering Connectors.

 

[96WhiteEclipse]

Try this: Sheridan Engineering Connectors.

Sent them an email. Haven’t seen any website updates since 2017 are they still around?

 

[19Eclipse90]

@brads might be better to answer that than me. As far as I am aware, yes - that’s who all the other vendors get the kits from.

 

[luv2rallye]

Make sure you find the cause of the short (if it's not the connector itself) or you may burn out a new connector.

 

[96WhiteEclipse]

Make sure you find the cause of the short (if it's not the connector itself) or you may burn out a new connector.

Could you help me out because I’m scratching my head trying to figure out what could cause this?

 

[steve]

I'm reading that as B-16 pin 7 Black/Blue Stripe. It's the trigger for the B-23 Blower Motor Relay (HI) coil. I could see it melting if somebody tried to jump the relay and used the wrong pins. It depends on the coil resistance from causing a short between the ignition switch and ground when the Blower Switch is on high.

Normally it would seem like it just causes the Blower Motor Relay to bypass the Blower Resistor and run the Blower Motor on high. In the later cars there isn't a Blower Motor Relay (HI) and all the current from the Blower go through pin 7 to pin 5 and then to ground. So if the Blower Motor was bypassed it would again be a short to ground.

I don't have a 96 manual so I can say if the 96 2GNT is like the 95 or the 97.

 

[luv2rallye]

Ok assuming your wiring is like the diagram in post 6. Your connector is the one on the blower switch (B-16). However do you see the 10 amp fuse #13 above the blower motor relay? That's the fuse that's blowing. The only way it can blow is if either:
(1) the low probability of the blower motor relay internal coil is shorting (which would happen when the blower is on whether the A/C switch {or Defroster switch} was on or not - this is a clue - does it happen without the A/C also?)
OR
(2) the far more likely case of the blower switch itself is internally shorting - which is a known issue.

I recommend getting a new/used blower switch.

 

[luv2rallye]

Ok I just saw that you have a non-turbo which means fuse #13 also supplies power to the A/C compressor clutch relay (does in my 1999 diagrams and probably the 1996 also). However that's not very likely the problem. I still maintain the problem is most likely a bad blower switch as this wears out on these cars. If you don't want to replace that connector just try first cleaning that pin up (at least on its inside contact area) with sandpaper and try on a replacement blower switch.

 

[96WhiteEclipse]

Ok I just saw that you have a non-turbo which means fuse #13 also supplies power to the A/C compressor clutch relay (does in my 1999 diagrams and probably the 1996 also). However that's not very likely the problem. I still maintain the problem is most likely a bad blower switch as this wears out on these cars. If you don't want to replace that connector just try first cleaning that pin up (at least on its inside contact area) with sandpaper and try on a replacement blower switch.

Got everything replaced and the AC is working great. Thanks for your help!