how do I get rid of this crud without messing up the electronics & stuff

I've tried engine degreaser, wd-40 & carb cleaner

 

It is hard to say what it is, but the stuff on the front of the battery tray looks like undercaoting. I am in the process of taking the undercoating off of the underneath of my car at the moment. I have been under there for over a week now. The thick stuff i used a torch at first and scraped it off. Then I used a wire brush, then I wiped the rest off with paint thinner. You can also use gas but be very careful with either. Also I do not know what paint thinner does to paint, I am doing unerneath. If it is just a light coat of undercoating you do not have to heat it up just rub it off with thinner or gas. Maybe someone else can answer the thinner on paint if it harms it.

 

I've managed to get most of it off with a wire-wheel, but I can't get to the stuff by the firewall or the engine, so I need a way to do that, without taking everything out & I need to take the charcoal canister out & get that area.

 

Try mineral spirits and a stiff nylon or fiber brush . i am working on the same problem . i am useing a spray bottle and lots of paper towels . many dealers sprayed this stuff on as an antirust protection . [ my car was a south florida car ] i just have it in a few areas , but it does look like crap . try it ,it worked for me . its pretty easy , cheap , and does the job , with no damage . [ kind of like my lady friend ] hope it works for you as well . hope this helps .

UNCLE TOM

 

use a bug and tar remover. i'm stripping off the undercoating on my T/A right now. first i scraped off the majority of it and the bug and tar remover does a great job of removing what's left of it. I have turtle wax brand.

 

ok I'll try it, I want to at least get most of it off so when I paint it, it won;t look bad..