MRAP 80mph speedo in HUMVEE

[DmentdDan]

I bought an MRAP speedo and am working on figuring out how to get it to work with my HUMVEE. Its electronic like the new 11 series HUMVEES and it only cost me $89 new. I am having a hard time getting info on info such as the pin out and/or a pigtail for it. We have anyone who can look up the cage number and get a pin out? A pig tail part number would be great but its not
necessary. I already called Medallion (the manufacturer) and they can't give out the info for the pin out.

 

[springer1981]

I bought an MRAP speedo and am working on figuring out how to get it to work with my HUMVEE. Its electronic like the new 11 series HUMVEES and it only cost me $89 new. I am having a hard time getting info on info such as the pin out and/or a pigtail for it. We have anyone who can look up the cage number and get a pin out? A pig tail part number would be great but its not
necessary. I already called Medallion (the manufacturer) and they can't give out the info for the pin out.

You posted images using links to your email account. No one but you can see them. I suggest you save the images to your computer and them use the "Attach Files" at the bottom of the post so everyone can see them.

 

[DmentdDan]

You posted images using links to your email account. No one but you can see them. I suggest you save the images to your computer and them use the "Attach Files" at the bottom of the post so everyone can see them.

Thanks I was dragging and dropping on my laptop, wondered why they would disappear.

 

[springer1981]

I have zero knowledge in MRAP anything but a couple things come to mind. That speedometer is generic in that the company that makes them also makes 100 other speedometers including Harleys, Fedex trucks, boats etc. A quick search on google turned up so interesting things. 1) that same speedo (nos) is available on epay for $30 free shipping. You could buy another and cut it open and make some educated guesses for the connections. 2) A company sells a GPS conversion that plugs into the back of some of the boat speedos they make however it specifically states it is driven by the engine computer and only uses 7vdc for power. 3) if yours is also computer driven by an engine ECM then it won't likely work easily in a HMMWV. 4) Depending on what the MRAP uses there is a possibility it is run off a CAN bus.

Here's a picture of the back of a similar speedo, same manufacture. The Red And Black are most likely the power but what voltage?

 

[springer1981]

Thanks I was dragging and dropping on my laptop, wondered why they would disappear.

Another thought, you could try putting 7vdc on the appropriate pins and seeing if the speedo goes through an initial check, usually the needle cycles. You can get 7.5 vdc with 5 AA batteries. If that works and you want to pursue trying to use that speedo then maybe consider buying the GPS and seeing if you can make that work with it.

 

[Mogman]

I picked one up for $30 just cuz it's just so purdy.
Every GPS speedo I have seen has a GPS antenna port on it, unless it is part of system and gets its data from another device.
I will be watching and looking for a mating connector.
EDIT, I have emailed Medallion for information, I am curious is this a 3 3/8" or 3" which would not fit our original dash hole.

 

[DmentdDan]

I have found the pin out info from a trouble shooting guide.

I haven't been able to get the technical specs for what the speedo is wanting as far as the data signal. I think I'll order a GPS sending unit and then wire two of my milwaukee 12 volt batteries in series for power and drive around in to see if the setup works and if it is accurate. As far as the pig tail goes... It seems a whole lot of medalion boat gauges used these connectors but I just can't find them so I may solder to the guage leads with an easily obtained pigtail and fill the gauge void with an epoxy or hot glue.

 

[Mogman]

I am pretty sure those trucks have an ECM, the data probably comes from that not GPS, some sort of CAN data although not high speed data as it requires a balanced pair of wires, would be marked data high and data low or + and -

 

[DmentdDan]

I am pretty sure those trucks have an ECM, the data probably comes from that not GPS, some sort of CAN data although not high speed data as it requires a balanced pair of wires, would be marked data high and data low or + and -

Right now I am theorizing that the speedo is just looking for the industry standard square wave. The GPS sender that I'm buying gonverts the GPS data to the square wave I think the electronic speedo wants. Ideally I would rather avoid GPS and have the correct sender attatched to the t/c but the prices on the senders have really shot up and I really like tinkering.

 

[Mogman]

Here is the response from Medallion.
The gauges require a control module to operate. The control module provides it 7 volts power, Ground, and a single wire data bus connection. The module itself is most likely picking up most of the info from the vehicle on the 1939 CAN bus.

 

[DmentdDan]

Here is the response from Medallion.
The gauges require a control module to operate. The control module provides it 7 volts power, Ground, and a single wire data bus connection. The module itself is most likely picking up most of the info from the vehicle on the 1939 CAN bus.

Great info! Shoots my theory down.

 

[springer1981]

Here's the GPS I came across... https://www.nauticlaugic.com/NL2.html

 

[Mogman]

Great info! Shoots my theory down.

I looks like the intended application had a complete cluster built by Medallion, hence the control module getting data from the CAN bus, all the data is there including oil pressure, temp etc. etc.

 

[Mogman]

Here's the GPS I came across... https://www.nauticlaugic.com/NL2.html

Looks interesting, at $300 you check it out and let us know how it works!!! would be pretty cool...
EDIT OH you have to have the MDC or MMDC computer to power it, dang..