Need Assistance with LMTV in Jacksonville, FL

[reelclassic]

I have an LMTV that I need help with. Can anyone recommend a good mechanic in the Jacksonville, Fl area to help with getting it going.

Thanks

 

[swbradley1]

Any more details? Someone might be able to help you on here first.

 

[Lmtv772]

I'm In port Saint Lucie. specialized in LMTV what do you need?

 

[Suprman]

The first gen trucks have an all mechanical motor and are pretty easy to start. You can call me I am pretty good with them 203-378-7105 I will be around for a few hours
Will

 

[FloridaAKM]

What is wrong with the truck that you need help to get it going? There are myriads of problems that can exist, helping to narrow them down is a must to getting your problems fixed!

 

[reelclassic]

My LMTV is powered with 3126B Caterpillar. I have bypassed the Battery disconnect unit after installing new batteries to just get power to the engine.
I can turn on the ignition switch on the frame under the cab next to the start toggle switch and battery on/off switch. When doing this it gives me the power
to roll the truck over, but not getting any power to the injectors. I am not able to start the truck from the red push button switch on the dash. I'm thinking there
has to be something stopping the ECM from telling the injectors to fire. Any help would be greatly appreciated. Thanks

 

[Derrickl112]

.

 

[Suprman]

24 volt goes directly to the starter from the battery bank with its own separate power wire. 12 and 24 go into the cab thru the polarity box and up to the power panel. If the power panel inadvertently got bent or flexed in some way the copper traces could break resulting in an open circuit. Center of the panel are bolt heads they are labeled with 12 and 24 volt. Verify the voltages there. I believe 2 of the bolts are always hot and the other 2 come on with the dash switch there are 2 big relays on the underside of the panel. You can look at the diagram on the inside of the power panel cover. Pull off individual breakers see if there is power being supplied to the breaker hot side. On the first gen trucks the transmission ecu has a separate vim module that has relays for neutral safety and other protections and will prevent starting if all is not right. With the wtec3 in the A1 trucks the trans ecu does it all. On the drivers side of the block towards the back is the engine computer. I believe they all use a 70 pin connector. If you google "caterpillar 70 pin ecm" pictures will come up showing pinout and you can verify if power is reaching the computer. Unfortunately all of these trucks have little electrical gremlins that you have to work out.

 

[Lmtv772]

If he has what I think he does then the truck will have the circuit breaker pods rather than the panel the older LMTV have, Disconnect the CTIS and see what that does. If it doesn't give power to start the truck normally , then try to unplug the light switch and see if the switch is ok. I tried to PM you, but never got an answer

 

[Suprman]

The 3126 should still have the circuit board. I think he got
the truck in pieces and put it all back together.

 

[Nearcoastal]

Hey,
lmtv772 I'm helping reelclassic with his 2003 lmtv here in Jacksonville. We are having to jump power across solenoids behind main power switch and we have 24 volts going to green ignition switch on dash but no power to start push button. Engine will roll over great if power is crossed over starter solenoid mounted on starter. if you could please contact me at 251-656-1640

 

[Nearcoastal]

replaced fuse panel

Replaced fuse panel and we have power to ignition switch
But still have no power to push button.

 

[Suprman]

When you turn the power switch on does it engage the fuel solenoid on the engine?

 

[Nearcoastal]

I have 24 volts @ fuel shut off solenoid on engine. I have power to CB 45 and CB 79 and CB 49 trips when energized. CB 45 says it's for h2o and pto switch.
There is also power going to k19 start inhabit relay but the light is not on, Is this good or bad?

 

[Nearcoastal]

2003 steward stevenson

Yes we have power to fuel solenoid and neutral start relay. On the circuit board the light for diff lock is on. And is there any other things that would not allow push start to work . Truck being in gear, parking brake not applied, cab position things like this. Because the center dash is missing in between circuit panel and panel behind steering column.

 

[Suprman]

There is a neutral safety but the transmission default is to go into neutral. If any wires are not connected or damaged that would prevent start. Do you have correct voltage to the trans ecu and the engine ecu? Low voltage causes a wide array of issues in these trucks. If you have power to both computers I would try jumping the starter solenoid and see if the engine starts. In the military a tech would plug into the truck to diagnose. There really isnt any easy diagnosis without the computer. Does the trans keypad light up with the dash power switch? If so you may be able to pull up error codes there for the trans at least. If the engine does run and the trans ecu has power then you can see if the trans engages.

 

[Nearcoastal]

Will check voltages and read codes next time I get a chance. Thanks for your help

 

[Nearcoastal]

Will the push start button work if the CTIS system is not installed????

 

[Lmtv772]

Will the push start button work if the CTIS system is not installed????

Yes, on the older LMTV (before 1999) and newer LMTV (after 2004) the push button works without CTIS being connected

 

[Nearcoastal]

So the 2000- 2003 should be the same? Because this is a 2003.5 I think????