HELP car wont start when battery in the trunk WHY?

[Nd4SpdSe]

running ok with the battery in the trunk, voltage is nice and stable too betweek 13 5 and 14 1 depending if load is on BUT

speaker has the whining noise that gets louder with higher RPMs and even louder with AC on.

I am searching the forums now but maybe someone can let me know.

thanks

Usually bad/insufficient ground in the headunit and/or the amp (if you're running one)

[Newfie_dan]

it can also happen if the capacitor on the alternator is getting weak just install a noise suppression unit and it should take care of it if the ground is not the issue.

[chrome730]

the wining noise is usually a result of ur power cable too close to the signal cable. atleast thats if ur running an amp to power ur speakers and sub

[Nd4SpdSe]

it can also happen if the capacitor on the alternator is getting weak just install a noise suppression unit and it should take care of it if the ground is not the issue.

that's just a band-aid fix and/or a last resort

[nolig2278]

i resolved the noise by grounding the XM and Radio directly to the battery instead of the metal behind the radio.
My + line from the trunk battery to the engine runs through the center of the car and right past the radio so maybe that was the cause.

If my positive line casing was cut and rubs the metal around the radio, i would know it right?

Thanks for all the help.

[Newfie_dan]

it can also happen if the capacitor on the alternator is getting weak just install a noise suppression unit and it should take care of it if the ground is not the issue you missed this part of it I think when you read what I said, I said that it can be used if there is no problems with grounding, I would make sure that the ground is taken care of first of course.

[nolig2278]

i am not get voltage drops other than for a split second whilt trun signal clicks or when extra load kicks in but the voltage kicks back up
could there still be a capacitor issue?

[Newfie_dan]

no it sounds like you are good to go, the alternator sounds like it is working just fine.

[john1983]

i resolved the noise by grounding the XM and Radio directly to the battery instead of the metal behind the radio.
My + line from the trunk battery to the engine runs through the center of the car and right past the radio so maybe that was the cause.

If my positive line casing was cut and rubs the metal around the radio, i would know it right?

Thanks for all the help.

if your positve line had a bare spot that came in contact with your radio you would deffanatly know you would hear each time as it grounds out and pops plus more then likely it would burn up your radio if your lucky only blow the fuse on the radio