A/C on but fans are off

Tiny
BETOLIVA
  • MEMBER
  • 2000 NISSAN ALTIMA
  • 2.4L
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 110,000 MILES
Hi, I am not an expert but know a little, everything started when my A/C was not cooling enough. So I noticed that both fan were barely moving I could stopped them with my finger. So with car on I disconnect the coolant sensor and both fan kicked in at high speed right away like when car is overheating. Check system and was a little low on Freon had small leak at evaporator. So I replaced evaporator, drier, coolant sensor. Vacuum system added a little oil and recharged it (134a) I got cold air but fans did not move low side was at 35 and high side was going higher and higher so I shut off A/C, even though I was getting power to fans I replaced both of them with new ones. Also replaced trinary high pressure switch vacuumed again recharged and same thing. Could the problem be the ECM? Please help me.
Thanks in advance.
Do you
have the same problem?
Yes
No
Saturday, April 22nd, 2017 AT 6:41 PM

6 Replies

Tiny
KEN
  • ADMIN
Hello,

It could be the ECM give you problems but it could be one of the relays, lets check the wiring diagram first and do some power and ground testing using a test light.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Here is a wiring diagram to get you started (below)

Please run some tests and get back to us so we can continue helping you.

Cheers, Ken
Was this
answer
helpful?
Yes
No
Tuesday, April 25th, 2017 AT 11:24 AM
Tiny
BETOLIVA
  • MEMBER
Hi Ken I will be away for about 10 days, I will get back to you then. Thanks for your help.
Was this
answer
helpful?
Yes
No
Wednesday, April 26th, 2017 AT 3:02 PM
Tiny
KEN
  • ADMIN
Sounds good, please do.
Was this
answer
helpful?
Yes
No
Thursday, April 27th, 2017 AT 12:31 PM
Tiny
BETOLIVA
  • MEMBER
Hi Ken, I've try what you told me tested all a/c and fans relay they all have power, have continuity on wiring also check voltage at coolant sensor (getting 4.8v just with ignition key on)which is normal, put everything together turn a/c on and bingo fans came on too, shut it off and let it cool off for about 2 hours and fans did NOT came on I thought it was cause engine was cold so suspected a defective coolant sensor(previously replaced with a new one) decided to check it again the next day, Next day turn a//c on and fans started to work right away in other words I have an intermitting problem now, also I wiggled wiring just in case no difference, please help I Am more confuse now. Sorry for this loooong reply. Thanks again.
Was this
answer
helpful?
Yes
No
Friday, May 5th, 2017 AT 1:05 PM
Tiny
BETOLIVA
  • MEMBER
Sorry I forgot could it be the Thermal controller that is attached to evaporator? I know that it controls temp. On the evaporator but what other function it has. Thanks again.
Was this
answer
helpful?
Yes
No
Friday, May 5th, 2017 AT 1:10 PM
Tiny
KEN
  • ADMIN
I don't think so, it must be one of the relays having a bad connection inside. Feel if any of them are hot?
Was this
answer
helpful?
Yes
No
Saturday, May 6th, 2017 AT 8:59 PM

Please login or register to post a reply.

Recommended Guides