Hello. I have a small 3 inch touch screen used to interface with my electronic fuel injection on my classic car. I would like to use a larger tablet or even hook it to my touch screen on my stereo head unit. I talked to the technical support people and they wouldn't help me, but they would sell me a 7 inch screen. I'm sure it must have software loaded on it, but is there anyway to get it off of there and onto something else? I am wondering if anyone has any experience with something like this, or could give me some pointers. I have an electronics back ground, so testing and soldering aren't an issue. Any help would be greatly appreciated. Thanks!

 

... small 3 inch touch screen ....

that level of detail is not going to help

 

You could try to work out the connections on the cable and see if it is some sort of standard like serial TTL level ASCII. If it is, then snoop with a serial terminal attached to see what the data is for each key press.
Or better yet, use a Bus Pirate....
https://www.sparkfun.com/products/12942
I doubt this is a trivial exercise though.

 

No you cannot..
There is nothing even remotely close to plug and play here..
Its likely all proprietary software intended to only work with what the manufacturer designed it for and its likely a massive project to even attempt to reverse Engineer it..

Give up now.. and buy the 7" if you want a bigger screen.. That will likely be far less costly in the long run..