Odd electrical problems

[TollKeeper]

That could be a fuse, or an alternator not putting out enough volts OR amps.

 

[Jadalexm]

An update for anyone interested. I broke down and paid the money for a month of alldata. I used all the wiring diagrams to find the data line splice pack. Unplugged the splice pack with my scan tool hooked up and saw all the modules do offline. I jumped the purple obd wire to each communication wire 1 at a time and found that the SCM or suspension control module was the one that made everything go haywire when I brought it back online. Got the plug diagram for that module and checked the communication wire right at the plug and found that everything before the module is fine. And with the module unplugged all the issues went away, except the air ride didn’t work. So until I feel like throwing 1000 dollars at a new scm, I pinned the communication wire out of the plug so I still have air ride and don’t have the electrical issues. Only downside is that I can’t communicate with the chassis system so I hope I don’t end up with an ABS code down the line that I have to read. Haha. But yea, dealer wants 700 for a new module and 350 to program. So that’s a pass for me. I’m attaching the wiring diagrams I used in case anyone else needs them in the future.

 

[Rocket Man]

An update for anyone interested. I broke down and paid the money for a month of alldata. I used all the wiring diagrams to find the data line splice pack. Unplugged the splice pack with my scan tool hooked up and saw all the modules do offline. I jumped the purple obd wire to each communication wire 1 at a time and found that the SCM or suspension control module was the one that made everything go haywire when I brought it back online. Got the plug diagram for that module and checked the communication wire right at the plug and found that everything before the module is fine. And with the module unplugged all the issues went away, except the air ride didn’t work. So until I feel like throwing 1000 dollars at a new scm, I pinned the communication wire out of the plug so I still have air ride and don’t have the electrical issues. Only downside is that I can’t communicate with the chassis system so I hope I don’t end up with an ABS code down the line that I have to read. Haha. But yea, dealer wants 700 for a new module and 350 to program. So that’s a pass for me. I’m attaching the wiring diagrams I used in case anyone else needs them in the future.

You can find used SCM’s on EBay for cheap. They don’t need to be programmed. I’ve swapped the one out on my 02.

 

[Jadalexm]

You can find used SCM’s on EBay for cheap. They don’t need to be programmed. I’ve swapped the one out on my 02.

Really? I bought a used one on eBay for 80 bucks and I plugged it in and the truck started once then the security light started flashing and it wouldn’t start again. Put the old computer back in and it went back to running fine. Figured it was because of the programming.

 

[Rocket Man]

Really? I bought a used one on eBay for 80 bucks and I plugged it in and the truck started once then the security light started flashing and it wouldn’t start again. Put the old computer back in and it went back to running fine. Figured it was because of the programming.

With an SCM? The module that’s behind the right rear cargo area panel? I can see that with the BCM or ECM but not the SCM. I’ve had mine unplugged before, no issues other than compressor didn’t come on.