hdj81 amplifier wiring question (1 Viewer)

[djsherif]

Hi guys,

Will be playing around with a new head unit as well as possible a sub/amp for rear. I've seen some on net say to connect ground to battery and not chassis, any thoughts? Which battery is best to use in either case?

Thanks

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[finderscuba]

For the head unit, buy a harness adapter so you can just use the original wiring. For the sub, ground to the chassis as long as your battery-to-chassis ground straps are in good shape and clean. Perhaps remove them, clean and replace.

Are you going to disconnect the factory amp for front and rear speakers?

 

[djsherif]

I already have an aftermarket head unit so only difference or addition will be wiring to rear for sub. Where are these ground straps?

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[finderscuba]

Heavy gauge cables from RH battery- to engine and to chassis. Also, LH battery- to series/parallel switchover relay, and from relay to engine. I think that's it.

You can measure the impedance between a negative battery terminal and a metal part of the engine, or chassis to see if you're getting a good ground.

 

[djsherif]

Thanks scuba I'll check the ground.

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[djsherif]

Out of curiosity though why would some say to wire the amp ground to the battery negative pole?

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[Douglas S]

A dedicated ground is always the best option. Always.

 

[langsen]

Out of curiosity though why would some say to wire the amp ground to the battery negative pole?

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It's to avoid picking up hum or alternator noise. If you wire it up grounded to a bolt somewhere, the same grounding bolt as the head unit ideally, and it doesn't pick up any noise then it's fine, not worth running a separate ground wire.

 

[acarlton]

When adding a subwoofer amplifier to the dual battery setup of an HDJ81, do I connect the power to the right or left battery, or does it not matter?

 

[Dork]

Connect to the right side battery, same as all the 12v loads on the truck. Left hand battery can see 24v while starting, and that could spell disaster for your new stereo equipment.

 

[acarlton]

Connect to the right side battery, same as all the 12v loads on the truck. Left hand battery can see 24v while starting, and that could spell disaster for your new stereo equipment.

Ah, that makes sense. Thanks! I'll connect it to the passenger-side battery on my RHD HDJ81.

 

[Dork]

No! Connect it to the DRIVER'S/Right side of your jdm/RHD truck. Unless, for whatever reason, yours is set up backwards.

 

[acarlton]

Gotcha. So right side from the drivers seat, not from when looking at the engine bay. Glad I clarified.