Srange problem after dual battery setup

[mustang_montana]

I recently setup a second battery in my 96 gt, mainly for the new alarm and a few other accesories, and the same day had my radar detector die and my exhaust solenoids die as well. When I say die, I mean fried without blowing a fuse...dont ask how..they just dont work anymore. I set the second battery up so it was grounded to the frame, then connecter the positive cable to a 200amp battery separator, then that to the positive of the main battery. Both are in my trunk, and the main battery is grounded to the frame of course. The solenoid is rigged to only connect the 2 batteries when the key is turned on, but I installed an overide switch so that I could disconnect them when I wanted. Everything works fine, no fires heh and the second battery charges at around 15 v with the car running, just like the main battery. I wired the battery separator to a key on fuse box I had made for other accesories, which is up front under the glove compartment. So the wire that turns on the solenoid does run past the wire that opperates both the radar detector (it is a whistler 2/ 16" gauge with remote sensors) and the electronic exhaust valve solenoids if that makes a difference, but its on its own fuse. Nothing else got "fried" not a single fuse popped, I hooked the radar detector up to just one of the batteries when separated, and it still didnt work. All grounds are perfect, no loose wires or anything, its just dead. Could this be some sort of reaction to either the dual batteries and the way they are setup or the huge magnet to operate the battery separator? Is this some sort of magnetic interference? Im at a total loss as to why these two accesories would fry. The exhaust valves had 12v by the way, everything should work but they are fried like I said. Any advise would be great, thanks guys.

 

[NO BRAKES]

how long has it been that those solenoids have been used? did the car sit all winter, then you put the battery in.. and now coincidentaly the exhaust ports dont open now too. maybe they are stuck in place?
adding a battery shouldnt hurt anything in your electrical system. if the first battery was already mounted in the trunk and you just added the other one back in the trunk to the first one.. then thats minimal wiring. id spray some pb blaster on the cutouts to try a free them up.

 

[mustang_montana]

thats a good point, but i had recently opened them up no problem. i can check them again, but i still don't understand what fried the radar detector. i dont know too much about magnetism, only that the battery separator is basically just a huge electro magnet, just wondering if maybe that caused the problem or if its something else all together.

 

[NO BRAKES]

did you check all fuses? or just the one for the cig lighter? sometimes the smaller fuses will be powered by the bigger 20/25 amp fuses in the same fuse box. its just something else to check. but make sure you put them back in the same position that they came out of. i cant tell you how many times ive messed that one up

 

[mustang_montana]

yeah everything has 12v to it, the radar detector is fried for sure, but the fuse its on was untouched. i had made a relay and fuse block for all the key on accesories, none of the fuses were blown and the speedcal+other 12v accesories on that fuse block still work. i dont know what happened, its not like the voltage was doubled or anything with 2 batteries, not parallel like it is.