Mk2 serial power problems

Posted by: paulj

Mk2 serial power problems - 25/08/2003 21:22

So I finally got all the stuff together to hook up my gps to my empeg... and I'm not getting power. metering out the serial port shows me +5V/+5V/-12V/0V/0V on pins 1-5. This doesn't seem right, especially the part where pin4 isn't supplying 12V as advertised. My serial# is 8<some number of 0s>298. Am I likely to have the missing ground pin in my sled? Could that be the problem?

Any help appreciated.

--pj
Posted by: paulj

Re: Mk2 serial power problems - 25/08/2003 22:48

Okay, so I'm pretty convinced I've got a sled/unit with no power and no ground. How hard is it to fix this in the sled itself? I've got everything else already expecting pins 4/5 to be pwr/grnd, is there an easy jumper I can do in the sled to make this work? Has anyone done this?

--pj
Posted by: tfabris

Re: Mk2 serial power problems - 26/08/2003 07:50

Am I likely to have the missing ground pin in my sled?


Yes. Please click here.
Posted by: mtempsch

Re: Mk2 serial power problems - 26/08/2003 10:56

expecting pins 4/5 to be pwr/grnd, is there an easy jumper I can do in the sled to make this work?

Even on the stock harness this is done externally from the sled - by splicing wires.
The stock harness is documented here and the functions of the various pins/plugs here.

The wires to pins 4, 5 and 8 on the serial plug are spliced and shrink tubed to the wires coming from the connector, fairly close to the connector. In the second pic on this page, you can see the splice on the ground wire (furthest right).

/Michael
Posted by: paulj

Re: Mk2 serial power problems - 27/08/2003 21:02

Thanks Tony. One more question: As I understand it, the miswiring is only in the sled. Are there actual wires to pins 4 & 5 that just arent connected right? or are the pins actaully not populated in the female dsub? Basically, is the deficiency correctable in the sled itself, or do I have to get power to my gps some other way? (and yes, I read the FAQs you pointed me at, t hanks, but the answer to the above is still unclear)

Thanks,

--pj
Posted by: tfabris

Re: Mk2 serial power problems - 28/08/2003 10:36

Basically, is the deficiency correctable in the sled itself,
Yes, but you have to actually look at the sled and see how it's wired, and do some quick tests with a wire continuity tester. Once you look at it with the tester, it should be dead-obvious exactly how the thing is wired up and which pins are doing what.

do I have to get power to my gps some other way?
One of the pins on the connector will be connected to the blue Amp Remote wire. That pin will supply 12 volts positive. If your GPS can take 12 volts positive on that pin, then all is well. To get the ground (which is usually pin 5), either figure out a way to ground the pin (not sure how easy this is on a miswired connector) , or change your grounding to use the serial cable shield instead.

All of the above should be dead-simple once you actually look at the connector on the sled. If you don't know how to use a continuity tester, or you don't know how to correct pinouts on a miswired connector, locate someone nearby who knows about this stuff and can help you.

Just keep in mind that the only serial communication pins the player uses are 2 and 3, (and 5 for ground if it's wired right), and if you hook up the GPS to the player it needs to only use those pins. Anything else would need to be power. If the GPS is trying to use handshaking pins, those need to be disconnected.