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CoryDaneRTSIIIL (4.17.253.46)

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Posted on Wednesday, June 18, 2003 - 12:43 pm:   

Ok Buss'n 2004 first, Hey Jack, thanks for your response about the dates on the next Buss'n Extravaganza. UNFORTUNATELY, you are scheduled to run the event during what the bosses are calling a holiday week and vacation is not allowed so I will be unable to participate. But the good news is I should be retired in 2 1/2 years and Ill make that one for sure. Thanks for the comments

OK, how did you guys run your instrument wiring to the rear of the bus?

Also, how do you get into the engine compartment from inside the coach of an RTSII???????

Did you run it with the AC/DC wiring, or did you run it in a separate (shielded) conduit?

I have to run from the fron all the way to the engine comp (except for the fuel guage which only goes half way).

I am in the midst of running all this wiring and I am in the middle of an octapus, good thing I marked where they all go(I hope). I am now concerned about noise or interferance from the other wire runs.

Also, did you have to run the rear camera wire separate or can it run with the instrument wiring?

I dunno about you guys that keep talking about your next bus but I can dog gone sure tell you that once this ones done, THERE AINT GONNA BE A NEXT BUS!!! I really enjoy working on her but I cant beleive all the studying and searching and information sharing I have had to do just to put on paper what will work in her. Besides, at that time I will be retired and I dont intend to spend that amount of my "FREE" time on another bus, this ones got to be the pinicle of bus conversion design right off the git-go or it will become a cabin on my remote properties.

Thanks for your support and help, and thanks Jack for your info. cd
Ross Carlisle (Ross) (66.238.216.18)

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Posted on Wednesday, June 18, 2003 - 1:01 pm:   

Its all the mind bending, back breaking work and sometimes mistakes on the first bus that makes the second so much easier. Just knowing where to get a part can save a weeks worth of research. I'm doing an MC9 now. I'd like to do an H345 Prevost when the prices come down. Maybe another 5 years or so.

As for the instrument wiring, I don't think it matters if they are shielded or not. It's the wire length that kills you. A better way would be to build an interface to accept the sender inputs that you have. The interface would send a data signal via fiber optics to a reciever in the front of the bus. The reciever would convert the data back to analog and drive the guages. This way you would have no loss due to long wire runs.

I have everything in my shop to build such a device, just no time. the time consuming part is developing the electronics and programming the microcontrollers. I figure thats going to be a winter project. I would like to have oil pressure, oil temp, transmission oil temp, fuel pressure and water temp.

Ross
Jayjay (198.81.26.108)

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Posted on Thursday, June 19, 2003 - 2:29 am:   

40 ft. is not a long enough run to create an appreciable voltage loss, not even #16. It takes 1,320 ft. of # 12 AWG wire to create 1 ohm of resistance. Line loss on long runs only becomes critical when you have a heavy starting loads, such as pumps or fans. The voltage drop on a piece of #16 AWG wire at 40 ft. (12V DC) is about (temp. compensation required) .00025 volts! You'll loose more than that in the connection interfaces at each end of the fiber optic, (unless soldered), plus the problems of getting the F/O ground square, plus the possibility of vibration induced fatigue causing the F/O to crack, plus the fact that you cannot make a sharp bend with the F/O, plus the fibers shearing off and entering your skin and eyes and collecting in your liver and lungs. Remember that F/O fibers are not biodegradabe, and may reside in your body indefinitely. Not a real problem for the occasional user, but it does exist. Your Choice! ...JJ
Ross Carlisle (Ross) (66.238.216.132)

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Posted on Thursday, June 19, 2003 - 12:22 pm:   

I was not referring to voltage loss. The problem is that most of these instruments use a resistance type sender. The added resistance of the long wire run makes the guages in the dash read quite abit lower than the mechanical guages in the engine bay. Anyone running electric dash guages knows what I mean.

The fiberoptic system eliminates the resistance loss of a long wire run and also eliminates stray voltage issues. The transmitter unit converts the analog resistance from the sender to a digital data stream and sends it via the fiberoptic cable. The reciever translates the data stream back to analog and drives the guage.

I've built a few of these for airplanes that were haviing trouble with stray voltage from strobes and avionics, so I know the concept works well.

Ross
Jack Conrad (Jackconrad) (204.193.117.66)

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Posted on Thursday, June 19, 2003 - 12:59 pm:   

Ross,
I have the problem as you mentioned, my dash (electric)gauges read lower then the mechanical in the engine compartment. Would using a larger gauge wire reduce this resistance? I am presently using 16 ga. wire. Please post more info if you get a prototype built using the fiberoptic. I would be interested in this. Thanks, Jack
Jim Stacy (12.87.108.194)

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Posted on Thursday, June 19, 2003 - 10:35 pm:   

Jack,

Another potential problem area is instrument ground. ALL gauges should have a hard wired dedicated ground with a direct connection to the negative battery terminal. Those who depend on chassis ground for a complete circuit will surely live to regret it. Even Detroit runs ground wires to everything now. You know that wouldn't happen if it would work the old way. FWIW.

Jim Stacy
CoryDaneRTSIIIL (4.17.253.109)

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Posted on Tuesday, June 24, 2003 - 6:15 pm:   

Ok youse guys.

I see we again have gone off course, only partially answering the question.

Lessee, the general consensus of ONE is that the cable does not need to be shielded or run in a grounded conduit, DO WE ALL AGREE????

How to get cable into the engine compartment, NO RESPONSE.

I am ASSuming, that running the length of the bus will have no ill effects except for a slight lower reading in the drivers area.
ALSO I am ASSuming that the AC or DC will not adversley affect the line for the FUEL GUAGE, the ENGINE GUAGES or the ELECTRONIC TACH/FUEL USAGE MONITOR.

Now that it is hot here, I know the job will be moving slower but if I can keep it in motion, I know I can get her done some year soon. LOL

"Imagine Your Dreams" cd

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