Temperature control switch or what?

ColdinMA
25

Asked by ColdinMA Dec 19, 2011 at 12:54 PM about the 2002 Honda Civic EX

Question type: Maintenance & Repair

I have a 2002 Civic and when I turn my heat on it only blows cold air even after warming up the car. Any suggestions?

18 Answers

Cain Williams
35

sounds like the heater control valve alright either stuck/ clogged or broken.

ColdinMA
25

Thank you Cain, I'll look into that. I just hope it isn't the heater core starting to go.

1 out of 1 people think this is helpful.
Alex Palmer
65

or maybe just a blown fuse

1 out of 1 people think this is helpful.
ColdinMA
25

Thanks Alex, I'll do a sweep of all the heater components starting with the fuse.

Greg Ahern
105

thermostat does the engine heat needle go down when you go on the highway if so that is it :)

1 out of 1 people think this is helpful.
ColdinMA
25

Thanks Greg, no the needle is steady. The heat only kicks in when the car is moving, it does not work at a stop light or in park. Is there some sort of link between the transmission and the heat control? It doesn't make any sense to me.

1 out of 1 people think this is helpful.
Greg Ahern
105

no there is not i am guessing that the fan is working ?? if so i would still change the thermostat they are really cheep to so it is worth a try and at the same time you could flush out the heater core

1 out of 1 people think this is helpful.
Bradford Andrews
345

i had this problem too i pulled the hoses too the heater core off the engine and blew the heater core out with an air compressor ran water through the core with a garden hose hooked everything back up and it worked fine after problem was the heater core was plugged up with a bunch of crap

2 out of 2 people think this is helpful.
Best Answer
ColdinMA
25

Looks like I'll be doing the heater core flush, I heard you can send some CLR through mixed with water and let it sit for while and then blow it out? Anyway, thanks to everyone for their help!

Kirk McCurdy
435

Could be air in the cooling system caused by burning coolant. Is it a single over cam v-tec engine? They are bad for headgaskets. One way to check is to remove spark plugs and use small camera down spark plug tube and check to see if piston tops have shinny clean spots. The clean spots are caused by the steam cleaning affect of coolant evaporating inside the combustion chamber which breaks up the carbon on top of the pistons. If this is the case then you have a bad headgasket.

Takoda Fraser
855

dude its your fan not working guarantee check you fuse for it shoud be under your left leg when you are sitting in the drivers seat

ColdinMA
25

The heat works only if I'm driving 45mph or higher. It needs something and I'm thinking it's the heater core.

Takoda Fraser
855

think of it this way when you drive air flows through the vents when your sitting still it doesn't so you get up to 45mph enough air is flowing through your cabin air intake right below your windshield so your finally getting air flow through it.. or can you tell that your fan is functional. i had an ef and my friend was pulling fuses and he pulled out the wrong one and i stopped getting hot air into the cabin so i suffered for about a week and found the fuse that was missing. it was blowing cold air but nothing warm was coming out.. im just sayin a 25 cent fuse over a heater core seems more appealing to me

1 out of 1 people think this is helpful.
Myron Peebles
0

I was frustrated when the temp control knob would not switch from Hot to Cold. Honda diagnosed and said I had a stuck heater box blend door and a faulty blend mix motor. "Replace the entire heater box and blend mix motor -$1173 incl. 6 hrs. labor.." The car is an '03 Civic. I replaced the sm. blend mix motor (very difficult) with a used 2002 part. No change! I crawled back under there and discovered a 2nd mechanism lower than the top unit (5 or 6" from the center column plastic duct -driver's side) and could see it trying to move as I operated the temp. control knob. I gave the top nylon arm a good upward push with my finger. It gave a snap/ freed up and now everything works great. Heat, Air Cond., cool! Seems that the internal heat control door was just stuck!

AliGator0502
0

My car is doing the exact same thing. Did you ever fix the problem? If so what was it?

MyronP45
10

Replaced AC compressor (they said it was a faulty control switch component on top of the compressor) and got AC working well. Later I had a problem with very marginal heat. The shop replaced the thermostat and flushed the heater core. Now the engine temp. gauge takes forever to reach operating temp. and will not hold operating temp. when it's cold out and blower fan/heater core is drawing coolant. They re-replaced the thermostat -same thing! They're now scratching their heads and I have another appointment. A good (180 deg.) thermostat MUST force engine temp. to remain hot!?? When I told the shop that I wasn't getting good heat they automatically replaced the thermostat and flushed the heater core -as if common and routine. (at least my heater core is good).

1 out of 1 people think this is helpful.
ColdinMA
25

Hey Myron, Thanks!! What I get out of your experience is that your car needed a "good (180 deg.)" thermostat? Is your heat working now?

MyronP45
10

I had a local shop replace AC Compressor with one used and they needed to splice the wires. Result, AC Fans ran all the time and overrode engine coolant temp (lg. compressor hoses were always frosted up!) so I would never get up to oper. temp and have heat. Temporary solution was to electrically disconnect Compressor. Now get heat but, of course, will not have AC. Returned to Honda shop and learned that I should have had specific OEM compressor installed. Now, b/c wires were spliced, they'd have to replace compressor AND wiring harness (est. around $2000 +). The car's only worth about $3,000. Maybe I'll just put a switch on the compressor.

Your Answer

Add photo

Related Questions

  • 1994 Honda Civic DX automatic: Does temperature censor regulate the cooling fan? 1 answer

    My 1994 civic dx temperature gauge does not work. Car overheats. Gauge still shows no temperature rise. Is the sensor bad? Does sensor in civic regulate the cooling fan? I found below in this link:...

    1994 Honda Civic DX Hatchback

    -

    Maintenance & Repair

  • Does anybody know about switches? If so, add me on Facebook, we need to talk! 1 answer

    1996 Honda Civic DX 2dr want to wire neon sticks to a light switch having problems switch stays on when car is off neon lights don't turn on, even when the switch is on

    1996 Honda Civic

    -

    Maintenance & Repair

  • how to repair rusted areas 1 answer

    i have no heat doesnt turn on cold or hot im guessing an electrical shrot.

    1990 Honda Civic Base Hatchback

    -

    Maintenance & Repair

  • A/C Troubleshoot Assist 1 answer

    So my 2002 Civic's A/C was intermittent for the past few years, either working great or not at all. This summer it's been in the "not at all" category. I popped the hood and turned the A/C on and th...

    2002 Honda Civic

    -

    Maintenance & Repair

  • security switch? 1 answer

    I have a 1989 honda civic lx. under the dash on the drivers side there is a silver pencil thin switch getting in the car I must have bumped it with my leg, the hazards came on and the car won't star...

    Honda Civic

    -

    General

Civic
Looking for a Used Civic in your area?
CarGurus has 62,957 nationwide Civic listings starting at $899.
ZIP:

Search Honda Civic Questions

Honda Civic Experts

#1 Takoda Fraser
Takoda Fraser
Reputation 800
#2 Tom Demyan
Tom Demyan
Reputation 530
#3 Jonathan Ford
Jonathan Ford
Reputation 510
View All

Related Models For Sale

Used Honda Accord"
1,136 Great Deals out of 67,494 listings starting at $950
Used Honda Civic Coupe"
260 Great Deals out of 11,375 listings starting at $4,440
Used Toyota Corolla"
1,055 Great Deals out of 61,794 listings starting at $1,000
Used Toyota Camry"
1,378 Great Deals out of 78,915 listings starting at $1,395
Used Nissan Altima"
1,357 Great Deals out of 86,759 listings starting at $1,000
Used Honda CR-V"
710 Great Deals out of 44,189 listings starting at $1,795
Used Volkswagen Jetta"
948 Great Deals out of 37,535 listings starting at $1,350
Used Nissan Sentra"
678 Great Deals out of 40,511 listings starting at $1,500
Used Ford Mustang"
864 Great Deals out of 29,983 listings starting at $1,993
Used Ford Focus"
1,328 Great Deals out of 62,767 listings starting at $1,000
Used Hyundai Elantra"
727 Great Deals out of 52,008 listings starting at $1,500
Used Acura TL"
332 Great Deals out of 6,686 listings starting at $2,200
Used Toyota Tacoma"
657 Great Deals out of 24,167 listings starting at $2,495

Used Cars For Sale

2013 Honda Civic EX For Sale
31 Great Deals out of 567 listings starting at $13,000
2012 Honda Civic EX For Sale
56 Great Deals out of 1,280 listings starting at $9,450
2011 Honda Civic EX For Sale
3 Great Deals out of 116 listings starting at $8,877