Alternator noise suppression

[remingtonh]

I thought of that. Every 3-4 years, I have a capable mechanic do a bumper-to-bumper inspection and fix everything that needs fixing. It's due for that this summer. I'll specifically mention the alternator and if it's even borderline, I'll have it replaced.

I never put the cheap crap on my truck. That's why it's immaculate despite its age.

(No cracks about the radio being "cheap crap". I knew it was entry-level when I bought it. I wasn't sure how much I'd get into ham radio, so I didn't spend the big bucks. It's working just fine and doing everything I want. If/when it craps out, I'll replace it with something high-end. If it doesn't crap out, then there was never a need for something else anyway. Besides, the radio isn't a permanent part of the truck.)

Your capable mechanic, as skilled as he may be mechanically, likely knows little about RFI mitigation.

 

[OkieBoyKJ5JFG]

Your capable mechanic, as skilled as he may be mechanically, likely knows little about RFI mitigation.

Almost certainly not, but if there's a question about the alternator, it's only logical to start there rather than chasing a bunch of other stuff only to find out that the alternator is failing.

 

[slowmover]

I'm not going to resort to a new alternator unless this one is failing or nothing else works, but I'll keep that in mind. Hopefully, changing my grounding location will fix the problem.

DODGE Transceiver Installation Guide will tell you to connect the unfused NEG to the BATT Neg fender connection bolt. (Remove paint).

I can use the Cigar Lighter power cord with my Lincoln II+ and hear the alternator (136A Denso) in my ‘04 2500 CTD. That’s not a surprise.

CORNELL-DUBILIER for Alternator noise control products after a KLF-2 is tried.

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[k6cpo]

When I installed the first radio in my then 13-year old Dodge Dakota, there was a little alternator noise heard in the radio's audio itself. I installed one of these filters in the power lead close to the radio. It's been through five different radios in the same vehicle and it's still quiet.

 

[TGuelker]

Another possibility is the electric fuel pump. The noise will change with rpm because the alternator is increasing the voltage to the pump. One way to test is to energize the fuel pump relay and transmit. An oscilloscope on the pump feed and ground should produce 7 or 8 smooth humps with no noise depending on the pump manufacturer. DENSO pumps will not have a waveform because they are brushless.

 

[AC9KH]

On a 16-year-old vehicle, I'd question the health of the alternator. If you can identify the alternator as the source (pitch of the noise rising and falling with engine speed), I'd consider replacing the alternator. No, it won't be cheap and, no, they don't make 'em like they used to. If you do replace the 'nator, get a name brand one and not a cheapie.

How about just fixing the alternator instead of replacing it? It's a simple three-phase AC generator with a bridge rectifier on each phase. If it's putting noise into the DC system then it has a leaky diode. No need to replace a perfectly good alternator because of a bad diode.

 

[AK9R]

Yes, repairing is an option if it's available to you. Assuming the alternator is repairable by the average home mechanic or you can find an automotive electrical shop that can repair it for a fair price in a reasonable time frame.