ForumsBasic TrainingOnline Maintenance ManualsThe M715 Zone Vin RegistryVPW's M715 Parts ListGalleriesLinks

Go Back   M715 Zone > General Tech > Open Discussion

Open Discussion Open Discussion for all M715 series trucks

Thread Tools Display Modes
Old September 17th, 2009, 07:07 PM
ldj1002 ldj1002 is offline
Basic Trainee
Join Date: Aug 2009
Location: Waco TX
Posts: 50
ldj1002 is a Soldier
Default Need wiring help

I am putting in new mechanical op and temp gauges and a 12V fuel gauge. I still have a 24V system so I will come off 1 battery for the 12V for fuel gauge. I'll use toggle switch to turn gauge off. Then I was gona clean up the wiring by removing some toggle switches and a push button switch which were for extra lights and a siren. One of the toggle switches has a piece (About 4") of factory wiring going to it with the # 490 on it. I looked in a schematic I found trying to find out what circuit 490 is. It goes from H on trailer plug to # 24 wire, looks very short. Another schematic for lighting only doesn't show anything there. Since I have a piece of 490 that was under my dash, I assume it used to be back at trailer plug. I haven't looked back there yet to see if I see where it was removed from. What was the H on trailer plug for and why is it shown on 1 schematic and not on the other?

My flashers don't work. To save me time trying to figure out how to troubleshoot this, does any one have a good procedure? There is current coming to steering column because it it lights up when I move lever? My truck is 7-67 delivery date #12631.
Reply With Quote
Old September 17th, 2009, 08:44 PM
brute4c's Avatar
brute4c brute4c is offline
Grand Poobah
Join Date: Sep 1998
Location: North Central Wisconsin
Posts: 11,485
brute4c is a Soldier

This is an early truck with the large underhood distribution box not the later solid state type turn signals I think?

Its not good to draw more off one battery than the other by tapping one for 12 volts...the states of charge between the 2 will get farther apart until one goes bad...unless you charge the 2 batteries seperately on a regular basis.

Wire 24 is: Light switch to blackout tail lamp
Wire 490 is a short wire spliced to wire #24 and runs to the trailer receptacle for the blackout tail lamp.
Lord send your Holy Ghost into our hearts and make the desire of our hearts Your Will.

Pro-choice, that's a LIE, babies don't choose to die!!
Reply With Quote
Old September 17th, 2009, 09:32 PM
ldj1002 ldj1002 is offline
Basic Trainee
Join Date: Aug 2009
Location: Waco TX
Posts: 50
ldj1002 is a Soldier

I do know about taking more off 1 battery isn't good. But fuel gauge? No more current than it draws surely it won't cause a problem. You check cells with hydrometer and in the old days when you could stick a volt gage on the lead straps between cells, there is always a difference in cell charge. Not much but some.

I don't know if my flasher is solid state or not but I think it is. It has heat sink fins all over top id that helps identify it.
Reply With Quote
Old September 17th, 2009, 09:36 PM
amphi's Avatar
amphi amphi is offline

Join Date: Dec 2006
Location: Onalaska, WA
Posts: 889
amphi is a Soldier

According to the link below this is the pin-out description for the eight wires in the receptacle:


See this link for wire number descriptions:

What style turn signal system do you have?
Both can be seen in this link:
Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
TBI wiring wrecker Modified Tech 3 February 29th, 2008 07:39 AM
Heater wiring fisherman Stock Tech 4 February 6th, 2008 01:17 PM
Wiring archjr Open Discussion 2 January 28th, 2008 04:42 PM
Wiring Diagrams Chop Parlor Open Discussion 3 November 17th, 2007 07:17 PM
Control box wiring Roger1952 Stock Tech 2 March 18th, 2007 01:24 PM

All times are GMT -7. The time now is 01:35 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
1998 - 2019

This site is owned and operated by:
M715 Zone, LLC
President: Jon Schmidt, User ID=brute4c
If you have any suggestions, comments, problems or questions, contact:

Use of this site means you understand and agree to our TERMS OF USE

Copyright Notice:
This web site is subject to the protection of the copyright laws of the United States and other countries. Except for Personal Use Only, you may not modify, copy, distribute, transmit, display, perform, reproduce, publish, license, create derivative works from, transfer, or sell any information obtained from any part of the M715 Zone website without the prior written permission of M715 Zone, LLC.

Written permission can only be obtained by contacting

Copyright 1998-2019