Question about fuses

[squonk]

So my altenator and battery died in my white nissan 240sx it's a 90. I put a new battery as well as new altenator in the car but it didn't solve all of the problems that were existing in it.

Here's a brief description of what is going on.

Prior to learning that my altenator was bad, my battery was dead. I put in a new battery but when I started my car the radio, seat belts, dome light, etc didn't work until I hit the gas pedal. Once I hit the gas pedal everything was working but the radio was still going on and off everytime I hit the brakes. So I tested the altenator and it was bad so I changed that. Now the altenator I changed it with could still be the problem but when talking with my mechanic recently he did another altenator change and had a similar circumstance happen in a different kind of vehicle. He was telling me about a couple of fuses located under the hood but doesn't know exactly where the fuses would be located on my 90 240. So I need to check these fuses as well as the fuses on the inside of my car to see if any of them could possibly be blown and if they're blown to replace them obviously. I know where all of the fuses are under the dash on the inside of the car but I have no idea where the fuses are located.

Does anyone have any idea where the other fuses are located so that I can figure out how to get my 240 up and running back into perfection again? This may not solve my problem but it's a lot cheaper and the easiest possible problem that could be effecting everything electronically in my vehicle.

I appreciate any and all of your help.

[ChickenWyng]

There are 2 fuse boxes under the hood. One right near the battery and another underneath the air filter. Hope this helps you out.