93 GT HVAC issues

M

moon9398

New Member

Sep 29, 2018

12

0

1

new mexico

Nov 9, 2018

#1

• Nov 9, 2018

• #1

ok I have a 93 mustang with electric fan, pretty new 180 thermostat and 3 bar mishimoto radiator. My heater will sometimes randomly come on after leaving it on and driving 30 plus minutes. But never reliable and it's getting colder so it's a priority. Rear defrost works great tho. My AC doesn't work either I think it may be the AC switch on passenger side engine wall cause the compressor doesn't kick on. Any help would be great. Im completely dumb in the terms of HVAC.

 

JD1964

there is enough sticking out to grab on to

15 Year Member

Jun 28, 2013

3,427

1,519

194

Maryland

Nov 9, 2018

#2

• Nov 9, 2018

• #2

When you say the heater randomly comes on, do you mean the fan comes on and off, or do you mean the air that comes out gets cold and then warm again?

 

M

moon9398

New Member

Sep 29, 2018

12

0

1

new mexico

Nov 9, 2018

#3

• Nov 9, 2018

• #3

John Dirks Jr said:

When you say the heater randomly comes on, do you mean the fan comes on and off, or do you mean the air that comes out gets cold and then warm again?

Click to expand...

So basically I'll turn it on full heat and it blows like it's on low but it's on high and while leaving it on for a while it will sometimes go from either cold to Luke warm air to hot but still doesn't blow hard enough to really get warm

 

JD1964

there is enough sticking out to grab on to

15 Year Member

Jun 28, 2013

3,427

1,519

194

Maryland

Nov 9, 2018

#4

• Nov 9, 2018

• #4

First of all, if the temp changes, check the coolant level. Low coolant will cause that.

 

General karthief

wonder how much it would cost to ship you a pair

5 Year Member

Aug 25, 2016

27,865

10,536

203

polk county florida

Nov 9, 2018

#5

• Nov 9, 2018

• #5

#1 does the fan just blow on one speed?
#2 are you stating that the temp fluctuates?
just trying to understand if you one or two problems

 

M

moon9398

New Member

Sep 29, 2018

12

0

1

new mexico

Nov 9, 2018

#6

• Nov 9, 2018

• #6

John Dirks Jr said:

First of all, if the temp changes, check the coolant level. Low coolant will cause that.

Click to expand...

Already checked that no issue and no change

 

M

moon9398

New Member

Sep 29, 2018

12

0

1

new mexico

Nov 9, 2018

#7

• Nov 9, 2018

• #7

General karthief said:

#1 does the fan just blow on one speed?
#2 are you stating that the temp fluctuates?
just trying to understand if you one or two problems

Click to expand...

1. No I can tell different fan speeds on low and on high but low is almost non existent and high feels like normal low

2. The temp doesn't fluctuate per se.
It's like it randomly kicks on and let's heat out not for long and with the blow speed being so bad it doesn't make a difference

 

General karthief

wonder how much it would cost to ship you a pair

5 Year Member

Aug 25, 2016

27,865

10,536

203

polk county florida

Nov 10, 2018

#8

• Nov 10, 2018

• #8

Appears to me you may have two problems. The first thing I would do is fix the fan speed problem, check for power at the blower motor, with the switch on high, then run a jump wire (12 volts) to the blower, it should blow fast, see where your air is coming out at,

 

90sickfox

Wasn't a pretty sight...and I've got big hands

SN Certified Technician

Mar 2, 2015

6,945

5,816

213

Nov 12, 2018

#9

• Nov 12, 2018

• #9

Sounds like you need a blower motor resistor... or the plug at the fan is loose or making a bad connection.

 

jrichker

StangNet's favorite TOOL

In Remembrance. Thank you for your contributions

Mar 10, 2000

27,512

2,811

234

Dublin GA

Nov 13, 2018

#10

• Nov 13, 2018

• #10

Here's the heater wiring diagram for your 92 Mustang.

Pigtail repair kits are available at most auto parts stores for damaged connectors. The hard part will be getting the parts counter person to look them up correctly.

 

Attachments

• 92-93 Mustang heater wiring.webp

  41.7 KB · Views: 277