The Radio Information Board

Hi all, I have a 2003 Passat wagon with an RFI problem comming from the AC fan controller that sounds like a fire siren. I have fixed most of the ignition noise and alternator whine and need any help I can get for the Fan controller which takes DC and converts it to a varying AC to run a varable speed fan on the radiator for the AC unit. I run 10 and 6M FM and during the summer months I have to turn off the AC in order to use the radio(syntor-x). I was hopeing to find the parts and or design to make a filter to put right at the controller DC input, sort of like the one that has been seen for the ford fuel pump RFI problem. My problem is finding the connectors so it would be plug and play and removable if nessary. Any designs or help would be greatly appreciated. thank you. Davie n 3 c hc u at atlanticbb dot net

Here is what I learned several years ago. According to a GM Service Bulletin:

1. Braid or twist the power and ground leads the full length of the cord.
2. The power cord should be routed from the location of the radio directly to the battery.
3. Make sure that the power cord and the antenna coax are routed as far away from the offending device as possible.
4. Using a high quality coax cable that has at least 95% braided shield will help if the interference is being picked up through the coax cable.

I know from my own experience:

If the interference is truly coming in at the power cord you can use a 6800 microfarad 16vdc electrolytic capacitor at the power plug of the radio. It is important that the capacitor is placed as close to the input of the radio as possible. You will need to solder it in place. Because there is a lot of vibration in a car crimping or wrapping the leads around the wire will not do much good.

As a last resort try replacing the switch.

I hope this information is not too late and it helps.

Regards,

Bill

Thank you Bill for your reply, I had a whole page in answer to your message but I hit the wrong button and lost it but I will try the cap mod . thanks again Davie n 3 c h u at atlanticbb dot net Stribel makes the controller and I wish I had there email address?