Alpine PDX-4.100 + Boston Pro60's ?

[KenL]

Any suggestions for grounding locations for the amp.?

When finding a decent ground point, you're looking for some sort of bolt that actually screws into a part of the vehicle's chassis (or into a nut that is welded to the vehicle's chassis). As ya know car paint is a pretty poor conductor so and standard free-turning nut/bolt combos are no good, even if they have a spring / star washer... I guess not too many people are keen on scratching off their paint for the sake of a good ground point due to potential for corrosion in the moister climates.

Using that principle, I think there's a good grounding point right near the suggested amp location, under the parcel shelf. Just locate your boot isolator switch (the one that disables the electronic latch on the boot) - the frame that supports the switch is screwed directly to the parcel shelf with two bolts.

I checked with my multimeter just then and appears to be <0.5 Ohm resistance between each bolt and the tail light ground which should be good enough for your PDX4.150. You would still need to test this point if you were running say a 1000W amp tho (in that case, suggest you either find a proper ground or run a 4 gauge wire directly back to the batt).

If you're happy with the that approach, suggest you consider making the location into a neat multi-terminal ground point so its easy to add other stuff later (eg. sub-woofer amp, lighting, motorised boot opener etc. ) - might even want to consider rigging it in such a way that you can use a single beefy capacitor for multiple components...

Aside, I was Dynamat'ing my front doors this arvo and noticed a bit of a problem in the drivers side door. Where the wires route through from the car into the door (through the rubber thing); instead of the wires just going through a hole in the door, they go through what looks like a huge plug/socket...

Quite a common occurrence with the new cars with all sorts of switch gear in the doors (European cars are worse with stuff like heated mirrors as well). The easiest way I can think of is:

• Lift off the boot housing and disconnect the plugs from the door
• Push the socket into the door by squeezing the one-way clips at the top/bottom
• Reconnect the plugs inside the door (I think there is enough slack to do that... not sure tho)
• Secure the plugs using cable-ties and/or double-sided adhesive tape inside the door so they don't rattle around
• After you've installed the speakers and run your wires back through the boot housing
• Lastly, cut up some double sided tape to fit the rectangular shape of the rubber boot and stick it back on the door - make it a good seal especially around the top and sides to prevent moisture from getting in ya door

If there's not enough slack in the OEM door wires - just rig up some male-female connectors like you are doing with the OEM head unit in your car.

Again, this is only stuff I've planned to do on my own Euro but not yet tried (no flames please if it doesn't work!). Seems like a clean approach if you intend to return your car back to stock if it comes time to sell. Hope these ideas are able to help you and any others interested!

Cheers, Ken