Looking For CUCV II Tahoe Wiring Diagram

[Humvee1538]

Hello All,
I am looking for information on the modified wiring diagram used for the CUCV II Tahoe.
Thanks

 

[Warthog]

We have not been able to find any tech manuals for the CUCV-IIs. Nor any wiring diagrams.

What diagram are you looking for?

 

[Humvee1538]

We have not been able to find any tech manuals for the CUCV-IIs. Nor any wiring diagrams.

What diagram are you looking for?

The battery goes dead overnight if you do not turn off the dash switch. I disconnected the rely on the firewall but then the truck does not start. I would like to by pass this system because it is my daily driver.

Yes I did get the GSA one and I am looking for the special front and rear mounts for the lifting shackles.

 

[Warthog]

All CUCV-IIs that I know of have that issue of draining the batteries.

The big silver relay on the firewall is the replacement for the starter relay. They removed it from the underhood fuse box. It is not connected to the dash switch.

I created a couple of diagrams. PM me your email address and I'll send you a copy

 

[Warthog]

Congrats of the GSA truck. Looked clean and a great price. Now to find out why it won't start.

 

[Stonepicker1]

Warthog, The single cab CUCV-II was having batteries issue also. It would drain the passenger side battery after two to three days.

I disconnected the relay on the firewall( black relay ) Monday. It was a pain to unplug and came out of the black plastic cover.

Now, four days later it started right up, no problems.

Going to have to buy a new relay and see if it solves the problem.

Thanks for the info.

 

[Warthog]

There are two relays that are energized when the B/O service switch is turned on. That is what is draining the batteries.

I am working on a plan to bypass those relay.

 

[Stonepicker1]

There are two relays that are energized when the B/O service switch is turned on. That is what is draining the batteries.

I am working on a plan to bypass those relay.

Thanks

 

[Humvee1538]

CUCV II Wiring

Thanks

Warthog,
GSA truck runs good. R&R plugs, fuel filter, fuel pump, gas tank and fluid changes.

This week the headlights would not come on and the warning buzzer started not to go off with the blackout switch in the "ON" position. I jiggled the blackout light switch and the lights came on. The switch is bad and when I hold it, the lights stay on but the buzzer is always on. I have 3 CUCV II Tahoes and the last CUCV II Tahoe that I purchased, the owner had pulled the black buzzer box because he complained that the buzzer was always on. This happened after he had purchased it from GL. I checked my third CUCV II Tahoe and the buzzer was also pulled.
I have a spare blackout switch from a M1009 and I will see if it is the same switch. I agree with you that the discharging problem does lie with the blackout circuit. Keep in mind that the headlight, "seat belt warning" , "keys left in the ignition" and "headlights left on" buzzer may have a influence.
Thanks for you info on the past wiring.

 

[boondock]

The blackout switches are the same.

My 'solution' to my Tahoe passengerside battery discharging in a few days was to install a cutoff switch on the battery. I use the Tahoe infrequently. It is an inconvenience to get started & on the road but less inconvenient than dealing with a dead battery.

I look forward to any wiring fixes that you CUCV II folks may come up with to solve what appears to be a possible poor design issue.

 

[Stonepicker1]

Warthog, The single cab CUCV-II was having batteries issue also. It would drain the passenger side battery after two to three days.

I disconnected the relay on the firewall( black relay ) Monday. It was a pain to unplug and came out of the black plastic cover.

Now, four days later it started right up, no problems.



Going to have to buy a new relay and see if it solves the problem.

Thanks for the info.

Well, that didn't work. Had a dead battery yesterday.

 

[Warthog]

I disconnected the relay on the firewall( black relay ) Monday. It was a pain to unplug and came out of the black plastic cover.

Did you end up buying a new relay? If so you can modify your old one to make a jumper.

Let's start at the beginning.

The military wanted blackout lights. In order to achieve that GM designed a harness that would make all the parts work together. Part of this was the addition of some relays. One for the headlights, one for the brake and turn signals and one for the B/O headlight. They also changed some of the wiring in the dash fusebox and the underhood fusebox.

Since most of use will never use the B/O lights in a combat situation, you can bypass some of the new B/O harness. I tested this over the weekend and it works.

The additional headlight relay and the brake/turn relay are energized when ever the B/O Service switch is engaged. Combined they draw about 1.5 amps. This is what is draining the 12v battery. By removing the two relays and making a jumper wire for the load, the battery drain is reduced to about 2 milliamps.

As far as the buzzer staying on, I have seen many times that the door switch on this style of trucks stay on all the time. This may be causing the buzzer to go off. The buzzer is not combined with the B/O Service switch harness. The Service switch does turn on the normal power that controls the buzzer and associated circuits.

 

[Warthog]

If I produce a wiring diagram, how much are you guys willing to pay....