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Ignition switch or relay?
1999 Ford F-350 Super Duty

Ignition switch or Relay?

(1999 Ford F-350 Super Duty)
My truck started this problem a few days ago. When key is out of ignition, the a/c blower and dome lights power on and off. We have pulled the relay for the dome light, but have not figured out where the problem lies. We are thinking ignition switch or ignition relay. Problem - where to locate them without repair manual and troubleshoot if this is not the reason it is causing this issue. Any ideas?
1 answer & 1 comment
Popular Answer
You might need to complete a diagnostic to rule out your body control modular. I was having same issues and then my power windows stopped working as well as the windshield wiper. We had already replaced on the relays, and then the clicking noise started shortly after their replacement. We just had the diagnostic completed yesterday and it shows that the Body Control Modular is faulty. When you locate it, you will need the center numbers between the letters in order to figure out which one you have to have replaced or rebuilt. You can try RockAuto.com for these parts - they are the most inexpensive I have found thus far. Good luck!
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on August 24, 2011
You were correct. It is the BCM. Next question, how do I locate it? I know it is under the dash, however, is it the black box behind the fuse block or next to the fuse block?
Thanks
General Diagnosis
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You might need to complete a diagnostic to rule out your body control modular. I was having same issues and then my power windows stopped working as well as the windshield wiper. We had already replaced on the relays, and then the clicking noise started shortly after their replacement. We just had the diagnostic completed yesterday and it shows that the Body Control Modular is faulty. When you locate it, you will need the center numbers between the letters in order to figure out which one you have to have replaced or rebuilt. You can try RockAuto.com for these parts - they are the most inexpensive I have found thus far. Good luck!
Sign in to reply
on August 24, 2011
You were correct. It is the BCM. Next question, how do I locate it? I know it is under the dash, however, is it the black box behind the fuse block or next to the fuse block?
Thanks

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