New Techs With No Real World Experience...

[Canuck]

Today I was asked to take a look at installing a radio into a Parks Canada truck.

I popped off the fuse cover and was shocked to see Cat5 wiring used as the power supply to the existing 10 amp radios. WTF!?

The tech used all the pairs... but this wire is rated to carry only 1 amp! His theory is that the current will split equally amongst the pairs...

ONLY in yer fricken dreams pal. Also he had some rambo combo of 10 and 25 amp fuses on the pairs. Real good that does when the wire melted 9 and 24 amps ago

Also the fusing was tapped on the load side of other fuses, as well as BOTH sides of others.

This is sure fire way of causing a vehicle fire and all sorts of other funked problems related with vehicle electronics and functions.

I asked the Warden if they were having any problems and he replies, "We've had several vehicle fires and all sorts of strange problems". No doubt.

I gave buddy a quote to fix up the wiring on the other radios, install an antenna for the new one, and check the cabling to the other antennas as his other radios weren't performing as well.

I just received a call that their tech said $225.00 labour was too much money and he cancelled.

Wow I figure $225.00 to rip out the other radios from the console, use real 14 gauge wire and proper fusing, and install a new radio and antenna was a deal.

Just had to vent.

[Ferno]

my god.. that tech is one cracked case.

when I went to install a car stereo for my vehicle, I didn't bother hotdogging it. I went and got wire that was one AUG size larger than what was needed. I didn't want anything blowing up.

[Canuck]

Let me clarify. These are his police radio, and Parks radios. Not his music.

These things take 10 amps or so of current each.
That's at MAX. transmit (TX) power, receive (RX) is using less.

So lets say at average the radios use 1-3 amps of juice during RX.

Go here for education purposes;
http://www.powerstream.com/Wire_Size.htm
and below the charts is a voltage drop calculator.

Enter in 22 wire gauge, 12 VDC, 15', 3A as the variables. Gads, I dropped 1.8 V and the voltage is barely above 10V. With one amp it's 11.4... generally most 12 V equipment usually starts operating here.

Now lets say the Warden is 4 hours into the bush and some drunk poacher with a gun is telling him, "No... I won't give you my gun or my kill".

When he pushes the talk switch on his mike to call for help, the TX power will now require much greater current from the circuit... punch in say 7 amps instead of 1.

Kind of limits my TX power doesn't it? Also the Warden is now SOL.

In real life the available voltage in the vehicle is 13.8V on average. But you can see from the calculator that there are still going to be issues with 22 gauge computer wire.

Strangely enough this has happened before with another tech. He was using telephone wire,(CAT 3) which has even less Voltage rating than Cat 5, to wire up PA systems in large stores. Runs and loops totalling over a thousand feet.

It sounded like crap. I called him up and asked him what his reasoning was to use Telco wire.
(I knew full well he was chincing out on the wire costs).

He claimed he could use 4 pair Cat 3 to run 1000 Watts of power. I called him on the code issue on doing that and then I told him to have a long and prosperous HI-FI career, but no thanks I'll stick to the proper wire for the job, and as a bonus have everyone be able to hear whats said on the PA.

Anyway I'll bug the Warden in the morning again and bring $1.20 worth of wire with me to prove a point.

[suicide eddie]

would not this break some sort of legal safety laws and maybe also manufactorers warrantys etc?

[JMEaT]

What a moron...

[Ferno]

Let me clarify. These are his police radio, and Parks radios. Not his music.

I know. I was making a comparisom.

[MD-2389]

Good grief....

Idiots like that shouldn't be anywhere near any sort of electrical equipment.