2004 Hummer Alternator Noise through RCAs

Does anyone have a solution to the alternator noise coming through the RCAs off the $4,500 Eclipse Navigational HU?

Things tested without luck:
It's not the amps or power to them, its from the HU for sure - tried a bench deck and the noise was gone.
Grounds are all to one place.
RCAs are not it - tried running a set outside the vehicle with same problem.
Put the deck on the seat, same problem.
I'm thinking it's the alternator in this Hummer beast - too much curent? But the why does the factory equipment not make engine noise?

Any thoughts/ideas would be much appreciated.

 

Where are the ground wires terminated to, what amplifiers / processors are used, did you use the factory head units ground wire (usually a big nono as there can be many other devices sharing the same ground).

 

Put a choke on HU ground and if that dosen't work you need to buy a DC-DC converter so you have an isolated power source for the HU.... I guarentee that will solve your problem... [img]graemlins/thumb.gif[/img]

 

60 ohms ????

By the sounds of things he ran ground wire for the HU to the point where the amps are grounded.. should be sufficient if you ask me (albeit a waste of time in this case)

Dude, only sure fire way to cure it is an ioslated power source for the head..

Edit: call gloabal semiconductor in missisauga 1-800-668-8776, I think they have em starting around $90

You may want to try a choke first, probably be like $15... check out www.globalsemi.com

[ December 04, 2004, 01:07 PM: Message edited by: Haunz ]

 

"we had the same problem in a 04 h2, we found that the impedence in the ground from the battery to the firewall was over 60 ohms with accesories on, we upgraded it and the noise went away"...
Finally someone who backs up their statements!!

 

i think its the combination of a bad vehicle with a bad head unit

 

Thanks everyone! Excellent ideas that we'll look into. Add indeed, all the grounds including the head unit are to the same spot (no factory grounds used). All the equipment is Eclipse and JL Audio.

 

There's a small lesson here;
Reminding us that today's cars electrical systems are not designed to handle the added load we subject them to.
Anytime I include an amplifier, I upgrade all grounds to the chassis and battery, including to the engine ground.
The battery is also a natural noise filter.
Have you noticed how actual wire type and guage in cars has changed over the past 15-20 years of cars?

 

^ the lesson is that the signal ground isolation in that eclipse unit sucks... [img]graemlins/laugh.gif[/img]