RFI in new Chevy
Posted: Sat Apr 19, 2003 1:54 am
I am posting this just to inform fellow hams. Please note I am a mechanic and have done many HF mobile installs. Below are the facts. The RFI happens on 20/30/40m & tries to engage the front axle.
JUST TO INFORM ALL OF YOU THINKING OF BUYING A NEW GM PRODUCT. GM WILL NOT WARRANTY ANY RFI ISSUES CONCERNING MOBILE INSTALLATIONS. I WAS JUST INFORMED OF THIS POLICY BY DEBBIE BARRY OF THE GM RESOURCE CENTER DUE TO MY COMPLAINT WITH MY NEW CHEVY 2003 2500 HD 4X4. UNLIKE MY FORD 2002 F-150 AND THE NEW CHRYLSERS THERE ARE NO BONDING STRAPS (GROUNDS) FROM THE FRAME TO THE BODY FOR RFI. SO IF YOU GO TO DAYTON ON MAY 16, 17, 18 TH Please ASK THE GM GROUP THAT WILL BE THERE THE FOLLOWING; WHY WON'T GM WARRANTY ANY RFI ISSUES WITH A NEW GM PRODUCT? BEFORE BUYING THIS TRUCK I WAS TOLD AT THE DAYTON HAMVENTION BY THE GM POWERTRAIN NOISE & VIBRATION CTR (DAVE HRIBAR) THAT GM WOULD WARRANTY ANY RFI ISSUES "IF THE RADIO TRANSMITTED AT 100 WATTS OR LESS". PLEASE NOTE THE LAST PARAGRAPH (7B)OF THE BELOW INSTUCTIONS. I WAS TOLD THIS DOESN'T MEAN THEY WILL WARRANTY ANY RFI ISSUES. JUST THAT IT MEANS THEY "WILL LOOK AT IT EVEN IF IT WAS A FORD PRODUCT". WELL I GUESS I'LL REPORT IT YOU DECIDE. 73 to view whole document go to;
http://service.gm.com/techlineinfo/radio.html
B. If any vehicle-radio interaction problems exist after following this guideline, the vehicle should be returned to a GM dealer for examination and resolution of the problem.
Update
Well it took me about 2 weeks to cure this pig...hihi
I could duplicate the problem by putting my 706 on 20/40M in CW and transmit my call with the mic. I would then hear the front axle motor run with the truck idling. I then started adding ground straps. I used 1 1/2" braided ground strap.
I first tried the axle, the front inner fenders to the frame, antenna mount with no luck. Then I added one to the right frame/box in the middle of the box, When I added one to the center of the cab on the right side 40M cleared up. When I added one to the left side of the cab in the center then 20M cleared up. I never had this much of an RFI issue before with a mobile HF install before. What made me realize this was on my old 2002 Ford F-150 I recalled several big battery style cables grounding the frame to the cab, and box.
I also would like to thank the ARRL for the private meeting they set up for me at Dayton with the GM group. He spent an hour with me out with my truck and went over all my problems with the RFI. He made several suggestions for the ground straps. Purchase .010 alum shim stock from Graingers which is a roll 6" wide and cut the width into 3 peices. Use this for ground straps. He also stated that the warranty issue has been addressed and GM will cover it. The only problem I could see is trying to find the Radio group at GM that will authorize it. He also showed me where the grounds were on the body to the frame. They were about 14-16 gauge. In my opinion very inadquite for RFI.
Anyway all is well.
JUST TO INFORM ALL OF YOU THINKING OF BUYING A NEW GM PRODUCT. GM WILL NOT WARRANTY ANY RFI ISSUES CONCERNING MOBILE INSTALLATIONS. I WAS JUST INFORMED OF THIS POLICY BY DEBBIE BARRY OF THE GM RESOURCE CENTER DUE TO MY COMPLAINT WITH MY NEW CHEVY 2003 2500 HD 4X4. UNLIKE MY FORD 2002 F-150 AND THE NEW CHRYLSERS THERE ARE NO BONDING STRAPS (GROUNDS) FROM THE FRAME TO THE BODY FOR RFI. SO IF YOU GO TO DAYTON ON MAY 16, 17, 18 TH Please ASK THE GM GROUP THAT WILL BE THERE THE FOLLOWING; WHY WON'T GM WARRANTY ANY RFI ISSUES WITH A NEW GM PRODUCT? BEFORE BUYING THIS TRUCK I WAS TOLD AT THE DAYTON HAMVENTION BY THE GM POWERTRAIN NOISE & VIBRATION CTR (DAVE HRIBAR) THAT GM WOULD WARRANTY ANY RFI ISSUES "IF THE RADIO TRANSMITTED AT 100 WATTS OR LESS". PLEASE NOTE THE LAST PARAGRAPH (7B)OF THE BELOW INSTUCTIONS. I WAS TOLD THIS DOESN'T MEAN THEY WILL WARRANTY ANY RFI ISSUES. JUST THAT IT MEANS THEY "WILL LOOK AT IT EVEN IF IT WAS A FORD PRODUCT". WELL I GUESS I'LL REPORT IT YOU DECIDE. 73 to view whole document go to;
http://service.gm.com/techlineinfo/radio.html
B. If any vehicle-radio interaction problems exist after following this guideline, the vehicle should be returned to a GM dealer for examination and resolution of the problem.
Update
Well it took me about 2 weeks to cure this pig...hihiI could duplicate the problem by putting my 706 on 20/40M in CW and transmit my call with the mic. I would then hear the front axle motor run with the truck idling. I then started adding ground straps. I used 1 1/2" braided ground strap.
I first tried the axle, the front inner fenders to the frame, antenna mount with no luck. Then I added one to the right frame/box in the middle of the box, When I added one to the center of the cab on the right side 40M cleared up. When I added one to the left side of the cab in the center then 20M cleared up. I never had this much of an RFI issue before with a mobile HF install before. What made me realize this was on my old 2002 Ford F-150 I recalled several big battery style cables grounding the frame to the cab, and box.
I also would like to thank the ARRL for the private meeting they set up for me at Dayton with the GM group. He spent an hour with me out with my truck and went over all my problems with the RFI. He made several suggestions for the ground straps. Purchase .010 alum shim stock from Graingers which is a roll 6" wide and cut the width into 3 peices. Use this for ground straps. He also stated that the warranty issue has been addressed and GM will cover it. The only problem I could see is trying to find the Radio group at GM that will authorize it. He also showed me where the grounds were on the body to the frame. They were about 14-16 gauge. In my opinion very inadquite for RFI.
Anyway all is well.