Big-time customer/ Big time problem

[garychoffmann 10+ year member]

Diagnosing a problem takes a little effort.... what have you done so far?

 

[MerkConvoy501]

disconnect rca one by one and see if its just one rca causing the issue

Its not just a single rca..

And to others if its a ground issue how would a rca to aux directly into the amp which is still grounded the same, fix the issue?

 

[BoomTaco64]

the issue goes away when you disconnect the rca cables right? if so then its the rca cable, rca run or the headunit.

 

[MerkConvoy501]

Diagnosing a problem takes a little effort.... what have you done so far?

Ive had the car for two days and have tried a bunch of things.. The first was to change the amp.. Second was to look over all the connections on all wires, rca's power ground speaker etc..

Have plugged each rca one at time as well as speaker wire.. Still engine noise

Have ran ground loop isolators same problem

have ran new rcas outside of the vehicle from hu to amp same problem

Have tried it with key turned forward but not running same problem

Have tried it with key turned backwards no problem

Have tried a rca to 3.5 directly into the amp no problem

Only thing i havent tried that i want to is unplugging this kenwood and trying a new kenwood radio

 

---------- Post added at 04:41 PM ---------- Previous post was at 04:40 PM ----------

 

the issue goes away when you disconnect the rca cables right? if so then its the rca cable, rca run or the headunit.

Yes it stops with no rca's plugged in and ive tried new rca's and it was still there

 

[BoomTaco64]

has to be the radio. try a different one and not use the ground in the harness. fords have horrible grounds in the radio harness try a different power source as well..maybe from the iginition itself

 

[CSCStang]

I had the same issue in my Mustang with the hu harness ground. I ended up grounding hu to the frame in the dash. That worked for me.

 

[MerkConvoy501]

Ok i will do that its just wierd because it started when i switched out one amp for another

 

[BoomTaco64]

bad radio ground will act differently with different amps.

 

[Joseph7195 10+ year member]

Marauder's are notorious for this. If you look under the hood, where there should be a factory braid cable to ground the body to the engine, and then the factory braided wire to attach the engine to the frame, you will see it is nonexistent. I don't know why they left them off those cars. If your ground is not looped back to the alternator, you will continue to get the whine.

 

[MerkConvoy501]

Marauder's are notorious for this. If you look under the hood, where there should be a factory braid cable to ground the body to the engine, and then the factory braided wire to attach the engine to the frame, you will see it is nonexistent. I don't know why they left them off those cars. If your ground is not looped back to the alternator, you will continue to get the whine.

Im gonna look into this.. Only thing is the equipment worked fine until i switched out for the new amp.. Realized that the amp wasnt the problem put the old amp back in and the same thing

 

[Kangaroux 5,000+ posts]

I've never had good luck with using the harness ground. I had some serious whine in my nissan when I did it. I ran a separate ground to one of the screws holding the headunit mount in place and it solved the problem.

 

[MerkConvoy501]

I got the car tomorrow and will continue testing tomorrow and will let ppl know what i figure out

 

[csu87 10+ year member]

since you own a shop, try swapping in another headunit and see what happens.

 

[gunz4me2 10+ year member]

Set your meter to measure AC, start the car, measure AC voltage at the main battery under the hood. If your measured AC voltage is greater than .7 volts with the car running, it is an alternator problem! Probably a rectifier diode going bad. Most of the Fords I owned over the years were known for having pathetic alternators that bled out excessive AC voltage.

While in theory, your batteries should filter this out, many times a capacitor will take care of a good bit of the ac ripple let out by the Ford alternator.

 

[AnthonyO 10+ year member]

Everything I have read leads to bad ground on the head unit.

And the reason it changed with amps, the new amp is pulling more current. Thus creating a lack of voltage on the head unit