No Lights

[Tkhawk01]

No Lights(Solved)

A couple of nights ago all of my lights and other electronics controlled by the black out switch stopped working. They were working fine when I got out and then I got back in turned them on and nothing happened. I've downloaded and read the TM and studied the wiring diagram. The fuses are good. The BO switch input has 9V when the BO is off, but when it is flipped up the voltage drops to 0. I thought that there maybe a short somewhere sucking the voltage down so I pulled the switch off and jumped the orange wires with a current meter but there was no current flowing there. Is there a voltage regulator somewhere that I need to replace or do ya'll have any other ideas. Thanks, its is a 86 M1009
Terrence

 

[kenz5380]

I don't have an answer, but I'm working through a bunch of electrical issues right now so I'd like to here if anyone has an idea on this.

 

[txmytx_catahoula]

So may of the CUCV electrical issues fall back on corrosion. I've gone back and cleaned every contact I find and it sure has helped me.

 

[caladin]

Watching for info. Electrical to me is one of the toughest things to resolve. I wish you luck.

 

[DonK]

Get out the schematic and start tracing the circuits. Chances are you'll find a loose or corroded connection. I've had trouble with the interal connections of the fuse block. Good Luck

 

[Warthog]

Follow along on the magical journey of powering the B/O switch.....

Evreyone should read the first few pages of the Troubleshooting Section of the TM 9-2320-289-20 or TM 9-2320-289-34 Technical manual to help understand the wiring diagrams and wire labeling.

On a STOCK system



1) The front battery supplies the power.
2) The front battery POS terminal is wired to the rear battery NEG terminal
3) From the rear battery NEG terminal, 12v is supplied to the 12v POS Terminal Block on the firewall
4) Via a fusable link power is supplied to the left side of the Headlight Fuse.
5) The Headlight fuse supplies power to the right side of the fuse holder (THIS CONNECTION OVERHEATS and MELTS the FUSE BOX)
6) There is s metal Jumper from the right side of the headlight fuse to the right side of the StopLight fuse.
7) Connected to the metal jumper is the large ORANGE wire
8 ) The ORANGE wire feeds to the center of the B/O Service Switch
9) When the Service Switch is switched ON, power is fed to the ORANGE/BLK wire
10) The ORANGE/BLACK wire goes to the main headlight switch
11) An additional ORANGE/BLACK wire feeds back to the Park Light and Flasher fuses

So boys and girls. If the Headlight Fuse is bad, melted, corroded or missing, none of the lights will work.

Check the Headlight fuse.

I would supply all the wire numbers, as I have in the past, but no one reads it so I will let you figure them out

.

 

[mistaken1]

The BO switch input has 9V when the BO is off,
Terrence

Should that not be battery voltage? More like twelve dot something volts.

Sounds like poor electrical connections are causing a voltage drop somewhere between the point you measured voltage and the positive post on the front battery.

"If it is electrical clean it". Start at the switch working your way towards the battery and clean all electrical connections with garnet abrasive paper or scotch bright pads and then coat them with either a conductive or non-conductive (as needed) electrical grease.

See if that does not help.

 

[rnd-motorsports]

Get out the schematic and start tracing the circuits. Chances are you'll find a loose or corroded connection Like stated above! Have fun , Not a job most like! I make good money in my shop and I do not like electrical work! but becouse it pays good you deal with it!!!

 

[Tkhawk01]

Thanks Warthog, I could not figure out where the power came in from, from the schematic it appears that the orange 914, 140 and white/black 913 just made a loop to the brake switch. I am also getting continuity between ground the fuses for the courtesy, panel, and flasher. So I guess I need to take the fuse block off, clean it, and check for anything melted in it. Thanks again guys, I'll keep ya posted.

 

[MakersTeleMark]

Also check the headlight plugs themselves, and especially the small ground wire coming off the front battery to the rad mount. Definitely post up your findings, a lot of us have had this problem. I'm looking into a permanent BO bypass.

 

[Tkhawk01]

Thanks guys, I got it fixed. Once I pulled the fuse block off of the firewall I noticed that the headlight fuse(I belive) had long past melted and been replaced with an inline glass fuse. The glass fuse was the issue, it wasn't blown but it had a bad connection and was loosing voltage and opening the circuit when a load was applied. It has been replaced with a new atc fuse and is good to go. Thanks for ya'lls help.

 

[Warthog]

Thanks guys, I got it fixed. Once I pulled the fuse block off of the firewall I noticed that the headlight fuse(I belive) had long past melted and been replaced with an inline glass fuse. The glass fuse was the issue, it wasn't blown but it had a bad connection and was loosing voltage and opening the circuit when a load was applied. It has been replaced with a new atc fuse and is good to go. Thanks for ya'lls help.

Glad you got it fixed.

Just as I suspected that it was the headlight fuse. Another one of the design flaws. Routing alot of the power thru one fuse

 

[mistaken1]

Tkhawk01, Thanks for the update.

Poor electrical connections can read just fine with a meter (virtually no load) but when a load passes through the poor connection (current flow) a voltage drop develops across the poor connection robbing downstream equipment of the correct voltage for proper operation and generating unwanted heat (IR2 heating) at the poor connection.