Radio installation - Something for everybody

[DBM58]

I have just finished installing a radio / CD / MP3 player and offer the following as comments and observations.

Wear sunscreen.

If I could offer you only one tip for the future, sunscreen would be it. The long-term benefits of sunscreen have been proved by scientists, whereas the rest of my advice has no basis more reliable than my own meandering experience. I will dispense this advice now:

i) If you are interested in knowing what the time is whilst driving, a radio that has a clock as part of the displayed features could be one of the criteria you use when buying a unit. So that the clock does not lose time when the radio is turned off, a permanent source of power must be provided. I took this from the back of the headlight switch between the two air vents.
ii) The unit that I bought (a Panasonic) was supplied with a connection harness with a (male) plug at one end - fits into the back of the unit, but bare ends at the other. The existing wiring in the MX5 dashboard ends at two (male) plugs that fit in to the back of the original radio. If these were cut these off then it would be hard to put the original unit back in - when it came time to upgrade to a later model car perhaps. I am fortunate enough to work with a company that supplies ready made wiring harnesses to all manner of industries, including those that fit car sound systems for a living, so it was fairly easy to obtain the matching (female) sockets and pin terminals to fit on the end of the Panasonic-supplied harness. Theoretically, the same plugs are available to anyone who asks nicely, as would the ready-made connector harness from an auto-electrician.
iii) On seats that have not been modified, the headrest speakers are in pairs. It never occurred to me that the left / right balance adjustment would control sound to the left and right ears. Intuitively, I expected it to be for the left and right sides of the car. Gazza has pointed out that in reality, I have no intuition so what would I know. Not much, except that real men do not own Britney Spears' albums - even if they were cheaply available from Far Eastern markets.
iv) In order to remove the original radio, the central dashboard fascia must be removed. In order to do this, the two top air vents must be removed - thanks zorruno for pointing this out. I was worried that if I used a screwdriver to lever them out I would leave gouge marks in the fascia plastic so fed a length of fuse wire through and back out of the vent grill, then used this to pull a piece of string through. By pulling on both ends of the string at the same time, the vent popped out very easily.
v) A multimeter set to test continuity (Greek symbol Omega W) is an easy way of confirming that the speakers were wired correctly ie. positive to positive, and negative to negative). In addition, by coiling small lengths of fuse wire around the ends of the meter probes, the ends of the wire fit in the holes in the harness plugs - useful when you want to check for continuity, or find which wire from the dashboard has the accessory power.
vi) I could not understand how a remote could be of any use when the buttons and knobs are all within easy reach. However, if you have arranged your MP3 files in folders, for example as in selections from various albums, then, at least on mine, using the remote is the best way of quickly moving to folder 17 on the list without having to go through ther previous 16. This could happen when you want to continue listening on the way home at the point that you ended when you arrived at work in the morning.
vii) I understand that in some cars, if you use the earth wire in the original dashboard wiring, for some reason that I do not know, it causes a short-circuit, and because (in some cars) the fuse that blows also protects the dashboard lights and rear lights, this earth cannot be used. Just in case, I attached the earth wire to a screw in themetalwork of the floor, just in front of the gear knob.

I offer this in the hope that it may be helpful, but I do know this, advice is a form of nostalgia. Dispensing it is a way of wishing the past from the disposal, wiping it off, painting over the ugly parts and recycling it for more than it's worth.
But trust me on the sunscreen.

Regards

David Moughtin

[zorruno]

on 25/05/2005 8:06 a.m. David Moughtin wrote:

I have just finished installing a radio / CD / MP3 player... Wear
sunscreen.

This is a good report, thanks David. I'd also add, wear a hat.

vii) I understand that in some cars, if you use the earth wire in the
original dashboard wiring, for some reason that I do not know, it
causes a short-circuit, and because (in some cars) the fuse that
blows also protects the dashboard lights and rear lights, this earth
cannot be used. Just in case, I attached the earth wire to a screw
in themetalwork of the floor, just in front of the gear knob.

Actually, what often happens in the MX5 is that people use a multimeter,
or one of those bulb-in-a-screwdriver thingies to locate earth in the
wiring harness. They often locate the headlight wiring instead, which
looks like a ground (headlights are low impedance whilst cold)... until
you switch the headlights on. This is not nice for the car stereo.

Also car manufacturers are notoriously bad at giving good ground
connections in wiring harnesses - often the main ground connections to
the body have bolts that loosen over time, or corrosion increases
the connection resistance. It is always better to make a new ground
with wire to an existing or new bolt in the body (and no - wiring back
to the battery for ground is _never_ a better way, for other
technological reasons)

cheers
zorruno