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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Fred Mc on August 29, 2017, 07:28:54 PM

Title: Wiring Problem
Post by: Fred Mc on August 29, 2017, 07:28:54 PM
I was having trouble starting my bus(GMPD4106) from the drivers seat. Through a process of elimination I have determined the problem is the wiring from the front electrical panel  to the back electrical panel. Not exactly sure how to read my ammeter for resistance but it does show a reading for resistance. So my question is the problem likely to be the connections at each end or the wiring itself?

Thanks for any help you can provide.

Regards

Fred.
Title: Re: Wiring Problem
Post by: Brassman on August 29, 2017, 07:35:15 PM
Yes.
Title: Re: Wiring Problem
Post by: buswarrior on August 29, 2017, 07:50:20 PM
Test the switches before you blame the wiring.

Many an hour has been wasted... moving switch parts fail long before stationary wires...

happy coaching!
buswarrior
Title: Re: Wiring Problem
Post by: Fred Mc on August 29, 2017, 09:12:51 PM
Well, I thought it might be the switch so I removed it.However as the nut was rusted on I ruined the switch removing it  so a new one is in order ;D. However further testing proved it was not a switch problem.
Title: Re: Wiring Problem
Post by: Zephod on August 30, 2017, 01:11:59 AM
Test the spade connectors too.. they can get crud inside them.


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Title: Re: Wiring Problem
Post by: bevans6 on August 30, 2017, 05:50:01 AM
Wires have been known to pinch, chafe, or rot.  To test the wire disconnect it from both ends, ground one end to a good chassis ground with a test lead, check the DC resistance from the that end of the wire to ground to make sure you have a good connection, then measure the resistance from the other end of the wire to a good chassis ground at that end.  You can look up the zero current DC resistance per foot for you wire, it's probably 14 gauge it you have a 12 volt bus and 16 gauge if you have a 24 volt bus, but it should be almost too small to measure.  If you have a manual it probably has a wiring section and there are probably spare wires that you can switch to.
Title: Re: Wiring Problem
Post by: Lin on August 30, 2017, 09:29:46 AM
It would seem that cleaning/renewing any connectors you could find would be a good place to start.  If you run a test wire from one panel to the other, does is start up correctly?
Title: Re: Wiring Problem
Post by: Fred Mc on August 30, 2017, 10:31:05 AM
Lin.

Yes, when I run a test wire from the starter switch to the stud (#19) in the rear electrical panel that connects to the starter relay it starts right up indicating to me that the problem is either the connection in the drivers electrical panel(stud#19) or the connection in the rear electrical panel(stud#19) or the wire in between.

Brian

Using my multimeter I connected one lead to the stud in the electrical rear panel(#19) and the other lead (using a long wire that I tested for resistance and found none) to the stud(#19) in the drivers electrical panel.
Is this the wrong way to do it? It did register a resistance. And given that I am connecting to the studs rather than the wires connecting to the studs) this probably eliminates any resistance due to bad connections to the studs. Am I correct in assuming this?

Thanks

Fred
Title: Re: Wiring Problem
Post by: bevans6 on August 30, 2017, 11:00:07 AM
if you test from stud to stud, you include any resistance in the connection between the stud and the wire.  I would probably take the wires off the studs and check just the wires next.
Title: Re: Wiring Problem
Post by: Fred Mc on August 30, 2017, 11:18:03 AM
OK, problem solved (i think)
I  used a spare circuit  and jumpered it at the front panel and rear panel and it now works.
Now to make a note in my manual so in a years time when I wonder why those jumpers are there I will know.

Now onto to other problems.

Thanks for the help.

Regards

Fred