There are three wires going to the DESS post
- White/Gray
- Black/Yellow
- Black
The black wire is ground. The other two wires use the black wire as common.
Here is what happens when you put a key on the post. There is a small reed switch in the post that connects to the black/yellow and black wire. The key has a magnet in it, so it closes the reed switch, effectively shorting the black/yellow and black wires together.The key contains an electronic serial number. You program that serial number into memory in the MPEM, so when the key is put on the post, the MPEM reads the serial number, and if it matches one that is stored in its memory, it gives you two beeps and allows the ski to start and run.
This turns on the MPEM. It begins sending out a signal on the White/Gray wire. The center post of the DESS post is connected to the White/Gray wire, and when you put the key on, it makes contact with both the center post and the ring on the post, which is connected to the black wire (ground) This signal "turns on" the key, and it sends the serial number of the key to the MPEM over the White/Gray wire. The MPEM reads this serial number, and if it matches one of the key serial numbers stored in memory, it activates the MPEM which sends out the two beeps. Once this happens, the key circuit is shut off. It no longer has any function, except that the magnet is needed to keep the MPEM alive. The short between Black/Yellow and Black must always be present to keep the ski running.
A lot of times I see recommendations to clean the key, for people that have problem with the ski quitting while running. This is inappropriate advice; cleaning is only recommended if the ski will not start.
The 97's > is known for corrosion problems with the MPEM connectors due to the stupid location they put the MPEM.
The learning key function is not available on the RFI models. It is only available on DI and 4-tec models
White lanyard or float = Learning Key
Yellow lanyard or float = Normal Key
Link to: HOW TO REBUILD YOUR LANYARD Credit to: WFO Speedracer
http://www.pwctoday.com/showthread.php?t=374391
- White/Gray
- Black/Yellow
- Black
The black wire is ground. The other two wires use the black wire as common.
Here is what happens when you put a key on the post. There is a small reed switch in the post that connects to the black/yellow and black wire. The key has a magnet in it, so it closes the reed switch, effectively shorting the black/yellow and black wires together.The key contains an electronic serial number. You program that serial number into memory in the MPEM, so when the key is put on the post, the MPEM reads the serial number, and if it matches one that is stored in its memory, it gives you two beeps and allows the ski to start and run.
This turns on the MPEM. It begins sending out a signal on the White/Gray wire. The center post of the DESS post is connected to the White/Gray wire, and when you put the key on, it makes contact with both the center post and the ring on the post, which is connected to the black wire (ground) This signal "turns on" the key, and it sends the serial number of the key to the MPEM over the White/Gray wire. The MPEM reads this serial number, and if it matches one of the key serial numbers stored in memory, it activates the MPEM which sends out the two beeps. Once this happens, the key circuit is shut off. It no longer has any function, except that the magnet is needed to keep the MPEM alive. The short between Black/Yellow and Black must always be present to keep the ski running.
A lot of times I see recommendations to clean the key, for people that have problem with the ski quitting while running. This is inappropriate advice; cleaning is only recommended if the ski will not start.
The 97's > is known for corrosion problems with the MPEM connectors due to the stupid location they put the MPEM.
The learning key function is not available on the RFI models. It is only available on DI and 4-tec models
White lanyard or float = Learning Key
Yellow lanyard or float = Normal Key
Link to: HOW TO REBUILD YOUR LANYARD Credit to: WFO Speedracer
http://www.pwctoday.com/showthread.php?t=374391
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