Solid-State DME Relay- Beta Testers Wanted
08-02-2015, 04:19 PM
#36
Nordschleife Master
Man... I just had a DME relay failure yesterday on the way home from a Porsche event and was thinking we still don't have a SS DME relay solution yet. Looks like my question has been answered. Nice!
08-03-2015, 06:58 PM
#37
3rd Gear
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08-19-2015, 01:56 PM
#40
Instructor
Join Date: Jul 2003
Location: South Western CT
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My relay gave out on me stranding me on the side of a highway yesterday. I rolled to a stop part way off an exit ramp without enough of a shoulder to get the car completely out of the travel portion of the road. The drivers side was still in the road.
I had made the jumper to bypass the DME/Fuel pump relay and I still had it in the car. And I had meant to put in instructions of where to hook it up to and hadn’t gotten around to that yet. I found the instructions on Clarks Garage web site on my phone and after some struggling to get the relay out by hand and then getting the connectors to the right terminals. All while trying not to get killed by a passing vehicle. I was able to get the car going again and worked my way home.
The relay that is farther away from the pins burned out the windings. I pulled it apart and removed the relay and fully tested it. I have a new DME/Fuel pump relay on its way from Paragon but I would have really liked to test this solid state one. I am going to try replacing the burned out relay in the assembly with a solid-state part if I can figure out what to use and then keep this one as a back up. Or I may strip the guts out of it and make it a bypassed unit just for emergencies. I could probably mount a switch in the housing and if I ever need to use it I can just put it in and throw the switch until I can get a replacement.
What would be the drawback to putting a DPDT switch in place of the relay as long as you always remembered to turn it off when you turn the car off? And I know the remembering to turn it off is kind of the gotcha.
I had made the jumper to bypass the DME/Fuel pump relay and I still had it in the car. And I had meant to put in instructions of where to hook it up to and hadn’t gotten around to that yet. I found the instructions on Clarks Garage web site on my phone and after some struggling to get the relay out by hand and then getting the connectors to the right terminals. All while trying not to get killed by a passing vehicle. I was able to get the car going again and worked my way home.
The relay that is farther away from the pins burned out the windings. I pulled it apart and removed the relay and fully tested it. I have a new DME/Fuel pump relay on its way from Paragon but I would have really liked to test this solid state one. I am going to try replacing the burned out relay in the assembly with a solid-state part if I can figure out what to use and then keep this one as a back up. Or I may strip the guts out of it and make it a bypassed unit just for emergencies. I could probably mount a switch in the housing and if I ever need to use it I can just put it in and throw the switch until I can get a replacement.
What would be the drawback to putting a DPDT switch in place of the relay as long as you always remembered to turn it off when you turn the car off? And I know the remembering to turn it off is kind of the gotcha.
09-16-2015, 12:00 PM
#43
Very interesting! As an apps engineer for STMicroelectronics and new 924S owner, I'm very interested in your design. Also, what are your thoughts about adding an NFC-based tag reader inside the relay, as a security system of sorts, blocking fuel pump operation until a tag is waved across the relay (or external reader below the dash, etc..)? These cars seem very easy to hot-wire and steal.
09-16-2015, 02:16 PM
#44
Rennlist Member
Also, what are your thoughts about adding an NFC-based tag reader inside the relay, as a security system of sorts, blocking fuel pump operation until a tag is waved across the relay (or external reader below the dash, etc..)? These cars seem very easy to hot-wire and steal.
09-16-2015, 05:34 PM
#45
Pro
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You can buy individual solid state relays and just wire them in if you want to. Are the relays tied together in any electrical way? If not, 2 separate relays could be wired in along with switches for testing or emergencies.
I have a cable tie wrapped around my DME relay [under dash location] to make it easy to pull if needed and also easy to find. It wraps loosely under the base to form a good loop that you can pull on.
I have a cable tie wrapped around my DME relay [under dash location] to make it easy to pull if needed and also easy to find. It wraps loosely under the base to form a good loop that you can pull on.