Lionel GP-38 Trips Transformer Breaker Immediately - Won't run -SOLVED

I think you’ll either have to have it repaired by a reputable person from this forum or untrust the seller and return it.  This didn’t happen from shipping.

That's a 16 year old loco. Those plugs don't come loose in shipping.

They're actually a bit difficult to unplug.

Imo someone's been fiddling around in there. That tag on the board doesn't look factory either.

If a return is an option. I'd consider it, as you have know idea how involved any issues might be.

@romiller49 posted:

I think you’ll either have to have it repaired by a reputable person from this forum or untrust the seller and return it.  This didn’t happen from shipping.

Well, perhaps not, but I guess to the meat of my question. Can this loco run with the smoke unit not connected with the wires/connectors displayed. If so, it's a distraction and I'll have to terminate the JST connectors with new ones. If not, then it's the solution. Just trying to figure that 1st part out.

Seller is reputable and the loco ran. They're being helpful so I'm at ease on that front. I'm just trying to determine the fix. Appreciate it.

I don't think anyone is going to be able to 100% come up with a fix until they trace out what is happening in there.  Since it's obvious that it's been "worked on" since the factory shipped it, there's no telling what goes where.

Before you run it again, assuming you figure out the other wiring, I'd insulate this connector, if it contacts anything, including the frame, you could be spending more in repairs!

@gunrunnerjohn posted:

I don't think anyone is going to be able to 100% come up with a fix until they trace out what is happening in there.  Since it's obvious that it's been "worked on" since the factory shipped it, there's no telling what goes where.

Before you run it again, assuming you figure out the other wiring, I'd insulate this connector, if it contacts anything, including the frame, you could be spending more in repairs!

Sound advice. Will do and thank you.

You didn’t acknowledge the seller was being helpful. My apologies.

@romiller49 posted:

You didn’t acknowledge the seller was being helpful. My apologies.

No worries! That's the crux of text only communication.

@RickO posted:

That's a 16 year old loco. Those plugs don't come loose in shipping.

They're actually a bit difficult to unplug.

Imo someone's been fiddling around in there. That tag on the board doesn't look factory either.

If a return is an option. I'd consider it, as you have know idea how involved any issues might be.

Yeah I was also curious about that little handwritten tag and meant to ask about it.

I just tested for continuity on the pickups and the rear truck pickups do not have continuity. So, there just seems to be more to it. I will work through it.

I would think it should run with the smoke unit disconnected, but the immediate short is another thing altogether.  They usually do not put shrink tubing on an unused terminal unless the builder is concerned about the open terminal touching something,  so you actually have 3 terminals on that plug where wires might go.  A good visual inspection of the wires from the pick up  rollers back may show something shorting to the frame.  After that an ohm meter would be necessary and logical troubleshooting to eliminate what is not causing the short, getting down to what is.   But, I would send it back, and try again.  I just did that with a 1688 that was advertised as working, and it was as dead as a post.

So, got it running! The short was somewhere in the rear truck. I believe a pinch between the electrocouple wire and the frame. Stripped it all down and cleaned it. Put it on the track and she fired up. Now to repair the smoke system wiring. Does anyone have the GP-38-2 in any road name they could reference? I cannot find the Lionel Supplement on this model. It's a 5 pin harness but only 4 wires present. As another poster indicated, it would be weird to have the insulated flex tubing on the 5th pin if it was supposed to be a dead slot. Thanks for all the help thus far.

Thanks for the update. It helps all of us.

@romiller49 posted:

Thanks for the update. It helps all of us.

Absolutely. The coupler wire came out of its channel and was rubbing. There was some exposed wire. Even when I made sure the exposed wire was not in contact with anything it still failed to fire up.

Another issue I found was This piece in the photograph was displaced and making contact with PCB board solders. This also could have led to a short. However when I isolated that as well on its own it still didn't solve it.

Either way, sometimes just taking it apart and ensuring everything is routed correctly and put back together well and you can get lucky.

@AKnorth posted:

Now to repair the smoke system wiring. Does anyone have the GP-38-2 in any road name they could reference? I cannot find the Lionel Supplement on this model. It's a 5 pin harness but only 4 wires present. As another poster indicated, it would be weird to have the insulated flex tubing on the 5th pin if it was supposed to be a dead slot. Thanks for all the help thus far.

Are you talking about the AC Regulator module?  These are no longer available and a very common failure item.  If this is dead, so is your smoke.

There is no supplement on any of the Legacy models, but there are some individual diagrams if you snoop around.

Here's a wiring diagram for an early Legacy GP7, should be pretty close to what you have.