DSX12VD power issues
I recently purchased the DSX12VD DC-DC regulator to power my car PC setup. I tapped the wires in the harness for the radio for constant 12v and accessory power and grounded it to the chassis. I turned the car on and checked for power in and out. It is getting 12v at the power and acc inputs, but there is no power coming out of the 4 pin molex connector. My multimeter was only reading something like 0.2v. It also was not reading anything out of the 12v spade connector on the board. From what I've read there is some type of LED on the board to signify the status of the board, but there is no LED light displaying. I need some help to see if the board is bad, or if I did something wrong. Thanks!
First, don't tap into the radio power harness. Those wires are very small (18GA or less) and not designed to deliver the kind of voltage needed for your computer power supply. You need to run a dedicated 12V line from the battery to your computer, using at least an 8GA wire (I'd go 4GA). You will also need a fuse installed within 18" of the battery. You can buy an amplifier wiring kit (buy a good one - you don't want a crappy power line) that will have everything you need, or you can visit your local car audio store and they'll give you everything you need.
In the short term, you can move your computer to your engine compartment and connect to the 12V terminal and the common ground on the chassis to test the power issue. You should also review the manual and make sure you connected everything correctly and set the jumpers correctly.
If you don't know how to run the wiring, this is a good starting place: http://www.caraudiohelp.com/how_to_i..._a_car_amp.htm
usually, the common rule is to install the fuse within 12" ;) (but the closer to the battery, the better)
also, make sure to not use factory ground wires(not including the factory battery ground)-- many times these can cause odd issues-- either no power, poor power, or ground loops..
and for the link that kegobeer offered, i'm a little bored, so i'll critique their how-to:
step #2. many cars have this, or a super-large grommet for small harnesses-- you can cut a 'x' in one of those oversized grommets and use those as well.. something else they lack here is to check if there is a forum for your car with specific details for routing the power wire that would normally go overlooked (my eclipse has a main power run through the left-side fender-- i would have overlooked this, and drilled my own hole if i didn't check the forums. pulling new wire through that same path has saved me lots of time..)
step #3. if you need a step-bit to drill your own hole, don't waste your money on a $40 UniBit. check harbor freight tools-- you could buy both sets for less then that..
step #7: i might have to copy&paste this elsewhere on the forum-- it summs up exactly why you need a fuse..
step #14: the common rule is "as short as possible"--most try to keep this around 12". something the instructions lack to mention is that this wire can be a larger gauge(lower number) but not smaller. they also recommend using a dremel to sand away the paint--i always use standard elbow-grease, and sand paper(at least 200 grit-- though the rougher, the faster it will go), as many times, a dremel might take away too much material-- you only need to sand through the paint..
That depends on where you are etc.
Originally Posted by soundman98
There is no "distance" per se - the real rule is "Protect [fuse] as close to the source [battery] as practicable (unless physical security is adequate or the protection itself causes increased risk of hazard)...".
Your "... the closer to the battery, the better" IMHO says it all.
(Keep in mind, such fuses are to protect the downstream cable(s); on rarer occasions the battery/supply, and rarely the end load/equipment itself.)
Thanks for the quick reply guys. I've installed car audio equipment before, so I'm familiar with how to run power wires from the battery for amps, etc. I guess I didn't realize that I needed this for the regulator. I just assumed that any 12v source should suffice. I just need to find a ring terminal that is small enough to connect to the board and big enough to accept a large gauge wire.
The ground is connected via a ring terminal to a metal bracket where the radio attaches. Perhaps it is not the best grounding location. The regulator and computer will be located in the glove box, so any suggestions on a good place to run a ground wire?
Lastly, the manual only specifies jumpers for the auto-turn off feature when power is cut. It is my understanding that even without any jumpers, the regulator should still output power when it receives power.
For reference, here are links to the manual and the product.
I ran some 10 gauge wire directly from the battery to this board. Used a brand new 15A fuse and still nothing. Its getting 12v in, but 0v out. I contacted the manufacturer, and i'm wainting for a reply.
Just in case anyone reads this or cares, I sent the board back to Mpegbox.com to be repaired.