Battery/charging light is on and the battery and alternator are good

Tiny
JONAHPK
  • MEMBER
  • 2004 TOYOTA HIGHLANDER
  • 11,100 MILES
2004 Highlander Limited w/3.3L V6-110,000 miles

AC clutch and cooling fan come on when car is off. One morning last week I came out to find the cooling fan running on the car. I unplugged the fan and went to work. Two days later the battery was dead. I charged the battery and the charging light came on the dash. The car runs fine, unless I turn on the heater or AC. I checked the battery and alternator and they are both fine. After checking fuses and other connections I went to put the ground terminal back on and noticed that the AC clutch engaged.

I unplugged the AC compressor and the cooling fan comes on and the battery light stays on. I unplugged the cooling fan relay and the light went off. But, the car won't run for long at idle this way. If the car dies, I hear some inconsistent clicks from the fuel pump and some clicks under the dash to the right of the steering wheel. I am just about at my wits end chasing this issue. Help?
Do you
have the same problem?
Yes
No
Friday, April 20th, 2012 AT 11:59 PM

3 Replies

Tiny
MHPAUTOS
  • EXPERT
I have seen this problem before the ECM is out and needs to be replaced because it control both the alternator and AC. Here is the location and I would try a used one you can get from Ebay.

Check out the diagrams (Below). Please let us know what you find.

Cheers
Was this
answer
helpful?
Yes
No
Saturday, April 21st, 2012 AT 12:06 AM
Tiny
JONAHPK
  • MEMBER
I replaced the ECM with a used one I got from a wrecker for $110.00 worked perfect! Thanks I love this site :>)
Was this
answer
helpful?
Yes
No
Saturday, April 21st, 2012 AT 12:24 AM
Tiny
MHPAUTOS
  • EXPERT
Good to hear, please use 2CarPros anytime we are here to help.

Cheers
Was this
answer
helpful?
Yes
No
Saturday, April 21st, 2012 AT 2:41 PM

Please login or register to post a reply.

Sponsored links