Disconnect your Batteries!!!

[Warthog]

When working on the CUCVs, it is important to disconnect your batteries before beginning work. There are many places on the truck that have live 12v and 24v connections that can be shorted out.

One of these connections is the starter relay under the dash. If you are installing the Doghead Starter Relay upgrade or even installing a radio, there is a good chance that the live terminals can short against the frame or a wrench.



If you have done the Doghead Relay upgrade you WILL have a better chance of shorting the starter relay as you now have a big exposed 24v terminal



If it happens on the starter relay, most of the time you will blow the fusible link on the 24v Positive Terminal block behind the rear battery.



Check your fusible link and repair if necessary.

Instructions for repairing a fusible link can be found in the Fusible Links -101 sticky

http://www.steelsoldiers.com/showthread.php?122571-Fusible-Links-101


More things to come.

 

[Warthog]

reserved

 

[goldneagle]

When working on the CUCVs, it is important to disconnect your batteries before beginning work. There are many places on the truck that have live 12v and 24v connections that can be shorted out.

One of these connections is the starter relay under the dash. If you are installing the Doghead Starter Relay upgrade or even installing a radio, there is a good chance that the live terminals can short against the frame or a wrench.

View attachment 486466

If you have done the Doghead Relay upgrade you WILL have a better chance of shorting the starter relay as you now have a big exposed 24v terminal

View attachment 486468

If it happens on the starter relay, most of the time you will blow the fusible link on the 24v Positive Terminal block behind the rear battery.

View attachment 486465View attachment 486467

Check your fusible link and repair if necessary.

Instructions for repairing a fusible link can be found in the Fusible Links -101 sticky

http://www.steelsoldiers.com/showthread.php?74776-Fusible-Links-101

More things to come.

I made a dense foam and vinyl cap that fits over the new starter relay to protect the unit from any shorts. The rubber used was recycled from padding found in a military case.

 

[Keith_J]

I noticed that when doing the relay mod. So I covered everything in heat shrink. But still, disconnecting both batteries from the system is good insurance. The electrical system in my 1031 SECM has plenty of add-ons, most of which run off the back battery to remove loading off the front battery/left alternator. And then there is the 24 volt air conditioning system that draws 70 amps on startup . Yes, my charging system gets a workout.

 

[Mainsail]

Covered!

 

[dstang97]

I used vaccum caps. And I have learned my lesson....

 

[M1009 NEWBEE 2013]

Lesson learned, the hard way!!!! liquid rubber applied today.

 

[84cucv1ton]

i put heat shrink tubing over them

 

[MarcusOReallyus]

Covered is good, but covered or not, you still should disconnect before working on the beast, unless you are testing for voltages.

 

[Ridgeback]

Yup...found this out the hard way troubleshooting a dead starter.

 

[combatmech]

Fried a grip of stuff on my first Blazer troubleshooting a fairly simple battery not charging problem. All you new folks read and heed. It's in the TM as well.