RF noise after HID headlight install

[cumins01]

I installed a set a HID lights from Retro Shop. When turning them on, I get a bad RF on my radio. With the lights on, it does not effect my EFI Live, alternator, or any other electrical items on my truck just the radio. When I turn the lights off, RF noise goes away and the radio station comes in clear. I also removed the antenna from the fender and it works great with the headlights on. Once I install the antenna and tightened it down, RF noise is back. I used a DMM to check grounds and from the battery positive to the chassis, ground studs, etc. I get the same reading of 12.6 volts. I tried a set of RF magnets with no luck. I grounded all the wires for the aftermarket HID lights direct to the battery. Anyone have any idea what else I can do? I like the lights as they are far better then factory. Is the antenna bad (cable, mount, etc.)? This is on a 2012 ST Ram crewcab diesel. Is there a TSB or something I have missed? Please help as I don't want to install the factory lights or pay for XM radio

 

[SnoKing]

What does the light manufacturer have to say about the problem? SNOKING

 

[cumins01]

He told me to add some RF magnets after the ballast. I did that with no change. Any idea when the antenna is NOT mounted to the fender (just laying inside), with the lights and radio on, I have no static in the radio?

 

[sag2]

A guess would be that the HID module is putting off a weak RF and when the antenna is in the fender it is closer to the antenna. Power down the passenger HID with the antenna in the fender and see if you still have it. If not try wrapping the HID module in some foil and ground it to see if it helps. I think the HID's put off heat so wrapping may not be a good long term solution but moving it might be.

 

[Tuesdak]

In chasing OnStar noise I find that adding Big 3 Ground kits to existing OEM grounds would put the alternator noise into the Onstar system. Putting the big 3 cables on their own locations away from OEM ground locations would eliminate the noise. I suggest grounding the HID's separately to a fender or engine block 1-2" away from any other ground and not direct to batteries. Also consider where the positive power is coming from. If this fails get different brand HID's that don't cause interference. The bulbs themselves could be the noise source. (As a side note grounding to the battery makes the battery cable an antenna for noise as the power comes from the alternator most of the time. Aka engine block is the better ground. )

 

[cumins01]

Thanks for the insight guys. I will try each one tonight and see if any work.

 

[cumins01]

In chasing OnStar noise I find that adding Big 3 Ground kits to existing OEM grounds would put the alternator noise into the Onstar system. Putting the big 3 cables on their own locations away from OEM ground locations would eliminate the noise. I suggest grounding the HID's separately to a fender or engine block 1-2" away from any other ground and not direct to batteries. Also consider where the positive power is coming from. If this fails get different brand HID's that don't cause interference. The bulbs themselves could be the noise source. (As a side note grounding to the battery makes the battery cable an antenna for noise as the power comes from the alternator most of the time. Aka engine block is the better ground. )

The power for the ballast/controller come from the driver side battery. The other power source comes direct from the headlight switch.

 

[tp0d]

If the antenna is grounded to chassis, get some nylon insulating washers to prevent the antenna from grounding to chassis.



Sounds like a cheap inverter circuit in the ballasts...

-j

 

[cumins01]

I moved the grounds from the battery (-) cable to the fender. The noise is almost gone. A lot better then before. Would a block ground be better?

 

[cerberusiam]

I moved the grounds from the battery (-) cable to the fender.

NEVER ground ANY add-on component to the battery in these trucks. All grounds need to be chassis, block, or frame attached.

 

[seafish]

NEVER ground ANY add-on component to the battery in these trucks. All grounds need to be chassis, block, or frame attached.

Cerb, curious why this is.

To this point in time, on my 2005 truck, I have already added two accessory fuse blocks with two different main breakers to each of them, distribute to accessories from the fused blocks with individual circuits and DO ground all accessories to frame as you say.

That being said, I recently got bit by an audiophile bug and I plan to add an extremely powerful stereo set up that includes 4 amplifiers totaling 3200 watts (obviously they own't be using that all the time or even necessarily at any point in time). I will be also wiring them with a 250 amp marine breaker right by each battery and 1/0 welding wire from EACH battery to a ditribution block next to the amps behind the rear seat. The distribution block I have allows me to safely connect the 1/0 from each battery jointly to the entire block, which will then distribute the power to each amplifier.I though the it would be best, given the total current involved (500 amps at peak rms) to actually also add a 1/0 ground wire from each battery negative terminal running to another ground distribution block (obviously NOT fused) for the amps ground points. My reason was to avoid any ground loops in the sound system to prevent any loop induced noise.

Instead, I COULD just choose a frame point near the amps and install a common ground lug ground instead of running 1/0 back to the batteries, but thought it would be better to give the current a direct return to the batteries rather then running that much through the frame.

Sorry if I am hijacking this thread, just want a quick opinion as to which you think is the better idea and WHY??

TIA.

 

[cerberusiam]

Short answer, to protect the computers. Many circuits on the computers are ground based to activate the component, there is ZERO protection from stray voltage or amperage generated or shorted onto the ground circuit. Tie it directly to the battery and it will force the charge out thru the system rather than dissipate it thru the frame\block\chassis resistance.

It is the same concept when wiring in sub feed panels to an electrical system, only the main commercial feed gets the neutral and ground circuits bonded; all sub feeds isolate the ground from neutral to protect back feeding and ground is run to earth ground at every point.

As the OP saw in certain cases tying directly to the battery is putting noise on the system and it is being picked up by a sensitive component. Any component that is relatively affordable has the potential to throw garbage into the system if something goes wrong. This happened a lot with the TST boxes when the first came out on the 3rd gens, people were used to tying components back to the battery and it threw all manner of weirdness into both the vehicle system and the TST system, moving from battery to the chassis for ground solved the problem.

 

[seafish]

Short answer, to protect the computers. Many circuits on the computers are ground based to activate the component, there is ZERO protection from stray voltage or amperage generated or shorted onto the ground circuit. Tie it directly to the battery and it will force the charge out thru the system rather than dissipate it thru the frame\block\chassis resistance.

It is the same concept when wiring in sub feed panels to an electrical system, only the main commercial feed gets the neutral and ground circuits bonded; all sub feeds isolate the ground from neutral to protect back feeding and ground is run to earth ground at every point.

As the OP saw in certain cases tying directly to the battery is putting noise on the system and it is being picked up by a sensitive component. Any component that is relatively affordable has the potential to throw garbage into the system if something goes wrong. This happened a lot with the TST boxes when the first came out on the 3rd gens, people were used to tying components back to the battery and it threw all manner of weirdness into both the vehicle system and the TST system, moving from battery to the chassis for ground solved the problem.

Ok Got it...I'll go with the common grounding point attached cleanly and securely to the frame.

Below is a good read further extrapolating what you said--

https://www.w8ji.com/negative_lead_to_battery.htm

 

[seafish]

There is even a really good explanation of the ground loops that the OP was experiencing--

https://www.w8ji.com/ground_loops.htm

 

[cumins01]

Thanks for all the replies guys. Never thought about the computers and such in these newer trucks. Once I moved it worked better. I relocated to a dedicated frame ground this weekend, all seems to working okay.