MG Car Repair: fuses, amp fuses, amp fuse

Question
I noticed that on one side of my 75 Midget the back tail light was out and the other side's parking light was out.  The other lights all worked.  When I checked the fuse the bottom fuse was burned out.  I took the second to the bottom fuse and put it in it's place and the lights came on.  I put the good fuse back where it came from, bought a box of 35 amp fuses and placed it in the empty slot where the old burned out fuse was.  Immediately it started to smell, so I pulled it out.  Why when I put the old 35 amp fuse that was working in the slot earlier, it worked fine, but when I bought new 35 amp fuses and placed it in the slot (now all fuses should be working) I seemed to be burning?  Not sure what I should do.

Answer
Hi Bob,
First you can not burn a 14 ga wire with a 35 amp fuse and if you used domestic fuses you can't smell a fuse burning. You might smell a Lucas fuse burn as the caps are not sealed well on the glass tube. However if you smell the fuse it has already burned.
When working on electrical problems on cars I made up a test lead with a resettable circuit breaker (35 amp) and with alligator clips on the end of the test leads. Other wise you will need a large box of fuses.
If you keep burning fuses, you need a wiring diagram of that car and trace all items on that fuse.
Are you talking about the "Side marker" lights when you say parking light, because the parking light and the tail light are just two names for the same light.
The right hand tail light, side marker and license light are on that second fuse. If you put a 35 amp fuse in and it burns away you need to look at each of the 5 lights on that fuse. Unplug the right side marker and parking light on the front and back at the lights (red wire) including the license light. Put in a new 35 amp fuse (second position) then reconnect each red wire (parking lights turned on)and note that the light comes on and the fuse don't burn. If the fuse blows when you reconnect one of the red wires then that unit (light) is where the short is. If the fuse blew with all of the red wires unplugged then the short is in the harness somewhere.
This is the method to find a short. In a shop we did too much of this kind of work to use fuses so we would make up a test lead with a resettable circuit breaker to take the place of the fuse.
Let me know,
Howard