Detecting an Object Through an Auto Firewall
Posted: Tue Jan 16, 2007 7:25 pm
I want to run a cable through an auto firewall. I found
an area on the engine side of the firewall that is free
of vacuum hoses, wires, etc. I have to drill through
on the cabin side, and that's the problem.
I can make some rough measurements on the engine
side where I want the cable to pass through, but there
is no way to transfer those measurements to the passenger
or cabin side. If I tried I would more than likely be off
by two or three inches. That would not be good since
I could easily damage something expensive!
What I need is some object I can tape to the cabin side
of the firewall, that would be detected on the engine
side. The firewall itself is heavy sheet metal with layers
of plastic, insulation, and who knows what else.
I was thinking about those small but very powerful
neodium magnets. Maybe if you taped one on the
cabin side of the firewall, it could be detected on the
engine side. Another possibility might be a simple
oscillator who's signal could be pinpointed on the
engine side.
I've always done some of the repairs and maintenance
on my own cars, but I'm not a pro mechanic. I don't
want to invest in an expensive instrument that would be
used once and put on a shelf for the next ten years.
When you think about all that steel and copper wiring
its hard to imagine what type of device I could build or
buy that would do the job.
Before someone asks the question, I have checked out
existing pass through points on the firewall. If I could
force the cable through a grommet or plug without
damaging something, I would probably have to use a
very long cable. For this project to work, the cable must
be six feet or less.
an area on the engine side of the firewall that is free
of vacuum hoses, wires, etc. I have to drill through
on the cabin side, and that's the problem.
I can make some rough measurements on the engine
side where I want the cable to pass through, but there
is no way to transfer those measurements to the passenger
or cabin side. If I tried I would more than likely be off
by two or three inches. That would not be good since
I could easily damage something expensive!
What I need is some object I can tape to the cabin side
of the firewall, that would be detected on the engine
side. The firewall itself is heavy sheet metal with layers
of plastic, insulation, and who knows what else.
I was thinking about those small but very powerful
neodium magnets. Maybe if you taped one on the
cabin side of the firewall, it could be detected on the
engine side. Another possibility might be a simple
oscillator who's signal could be pinpointed on the
engine side.
I've always done some of the repairs and maintenance
on my own cars, but I'm not a pro mechanic. I don't
want to invest in an expensive instrument that would be
used once and put on a shelf for the next ten years.
When you think about all that steel and copper wiring
its hard to imagine what type of device I could build or
buy that would do the job.
Before someone asks the question, I have checked out
existing pass through points on the firewall. If I could
force the cable through a grommet or plug without
damaging something, I would probably have to use a
very long cable. For this project to work, the cable must
be six feet or less.