On our 1998 S70 GLT last week the Electronic Climate Control (A/C unit) integral button lights did not illuminate as usual after start. The ECC unit would not start, appeared dead.

With the nice weather and the lack of need for climate control we did not use the ECC for the past week. Last night after starting the car to drive home, the dashboard lights & sunroof failed to operate in addition to the ECC.

I checked the fuses and replaced # 31 & # 35. 31, a red 10-amp controls the dashboard background lights and sunroof. 35, a clear 25-amp, controls the ECC. # 31 was blown but the # 35 was intact. I replaced both with spares of the same amperage. Immediately after replacement both the dashboard lights and ECC worked normally. The car was parked for the night.

Today the car was driven three times. The first two times both the dashboard background lights and ECC operated normally, however, on the third use of the car after starting, the dashboard lights and ECC failed to operate. I checked the fuses again and the dashboard lights fuse was blown but the ECC was intact.

All other electrical components are operating normally.

Any ideas?

Thanks.

 

Was the A/C on when the fuse blew?

 

Tech:

I don't remember as I noticed it after I started it.....usually I turn off the fan prior to turning off the ignition in order to have the fan off for the subsequent engine start.