Loosing the will to live.

[Stevea4117]

Ok after a breakdown during a tour at the end of September found my ecu had been fried by a dodgy alternator. Both have been replaced now. Got it all back together. Used the opportunity to replace fuel filter whilst alternator was being overhauled. Once back together put some fuel in her and tried to start her up. We'll after a short time smoke started coming from the fuel pump ground wire stopped immediately and found it had completely melted itself and the live. Made a new set and doing the same. I'm pretty crap with electrics and don't understand electric diagrams. I've been told to check main earth on bike. I assume that's just under the back of the tank attached to frame.
Sorry to be a pain I'm about to give up. Not ridden her for months

 

[St-Gerard]

Any time I have electric gremlins first order is clean all grounds, and then connections and look for shorts to ground , might want to look for shorts to ground first

 

[mudduc]

Sorry for your pain, @Stevea4117.
I was going to see if I was close enough to stop over and help...then I found your location was "Kent". Great!

But I looked around and couldn't find you. Huh?!?

Later,
Kent Larson in Woodbury, MN.

p.s. Sorry, for the humor and lack of help. If you were close, I'll grab a meter and come over. If not close, I'll let better explainers talk you through it here. Luck!

 

[Roger]

First thoughts are that the pump is faulty or there are trapped wires somewhere. Is that circuit fused? .......Should be - but I'm not familiar with 1300's.

 

[Stevea4117]

First thoughts are that the pump is faulty or there are trapped wires somewhere. Is that circuit fused? .......Should be - but I'm not familiar with 1300's.

Yes mate fused with a 20amp

Sorry for your pain, @Stevea4117.
I was going to see if I was close enough to stop over and help...then I found your location was "Kent". Great!

But I looked around and couldn't find you. Huh?!?

Later,
Kent Larson in Woodbury, MN.

p.s. Sorry, for the humor and lack of help. If you were close, I'll grab a meter and come over. If not close, I'll let better explainers talk you through it here. Luck!

Mate how dull would life be without humour? Never had a problem with her for years and all of a sudden everything I touch goes wrong. I'm throwing money at her like she's on a pole in a strip club

 

[Al st1100]

Sound like that ground circuit is over loaded. Something else is missing a ground and is taking it from that wire. Double check all grounds everywhere. Probably where all the problems started. seehttps://www.st-owners.com/forums/threads/st1300-only-one-ground-point.181970/#:~:text=Ground cable at the starter,then to the main ground.

 

[St-Gerard]

Multiple wire harnesses ,like by the steering head are a problem area on older bikes ,wiring doesn,t like to be moved around much , have had to do a lot of slicing new wire in that area.

 

[Ron]

Mate how dull would life be without humour? Never had a problem with her for years and all of a sudden everything I touch goes wrong. I'm throwing money at her like she's on a pole in a strip club

Never heard that one before!

 

[DannoXYZ]

I call dibs on Steve’s bike if he gives up…

 

[Upt' North]

Hang in there Steve, you know you're enjoying it .
Someone will come along who knows what they're talking about soon, but in the meantime. Is this all connected, the initial issues and the subsequent detritus.
If so you need to get to just about every connection and especially the earths wherever they may be hidden and I see emery cloth and contact cleaner in your future. Test the pump by connecting up a separate supply if possible and check that's OK. If it melts the wires then you could be onto something. If not at least you can move on.
If none of this works I see 5 litres of unleaded and a match in your future.

 

[Andrew Shadow]

I would trace the wires from the fuel pump back to their source. Normally the fuel pump fuse would have blown before the wires melted. That is what the fuse is there for, to protect the wires. Because the wires melted makes me wonder if someone bypassed something or connected it incorrectly somehow.

 

[Uncle Phil]

I wonder is 20amp the correct fuse size for that circuit or should it be smaller?

 

[DannoXYZ]

Yes, 20a is proper size for FI fuse L that powers entire EFI system and fuel pump.

If brown power-wire to pump and pump’s green earth wires are melted, that power must be coming from somewhere other than fuel-pump relay (otherwise, would’ve blown FI fuse). Maybe some other power wire got pinched onto pump’s wiring between relay and pump?

1. pull fuel pump relay

2. disconnect fuel-pump connector
3. measure impedance of fuel-pump itself across terminals where connector plugs in, ohms = ??

4. at fuel-pump harness connector, measure resistance between grn wire terminal and frame earth, ohms = ???

5. at fuel-pump harness connector, measure resistance between brn wire terminal and frame earth, ohms = ???

6. from fuel-pump harness connector, trace grn wire to other end. Is wire insulation whole all way to frame earth? Not melted, exposed or connected to any other wire?

7. from fuel-pump harness connector, trace brn wire to other end. Is wire insulation whole all way to fuel pump relay socket? Not melted, exposed or connected to any other wire?

 

[Ryan_B]

I know you said you are crap with electronics, but could you clarify? Most of the responses assume you have a multi-meter and know the basics of using it. Do you have a volt meter or test light that you can check voltage with? Here is a very good schematic that you can download and zoom in on that shows all the power wires.

https://www.st-owners.com/forums/threads/st1300-wiring-schematic.90873/

First thing I would be looking for is burnt or broken grounds (basically just echoing what others have already mentioned). What that means is you are looking for a corroded or a broken ground wire/connection to the frame. DannoXYZ is saying nearly the same thing, there is a ground not connected/broken/corroded somewhere and the only "return to earth" that circuit is making is through the fuel pump or housing which is melting wires as it takes on too much power.

If it were me, I would probably be suspicious of something not connected around that alternator. You had it changed, so something possibly is loose around there? Could be related to the alternator going out too, so it may not be anywhere near that vicinity.

Good luck! You have a bunch of helpful people on here that are happy to direct you, you have to let them know your limits and what you are seeing though. Anyone can learn! I always tell me kids "it is already broken, might as well try to fix it".

Ryan

 

[St-Gerard]

May sound crazy but one way to fix it is buy a complete wiring harness and replace the burnt out one.

 

[DannoXYZ]

May sound crazy but one way to fix it is buy a complete wiring harness and replace the burnt out one.

That’s one solution! Risk is that additional errors will be introduced into system, such as leaving connectors unplugged, or plugged into incorrect places or wiring itself damaged in process. There’s only 5 connectors needed to undo to replace alternator and something still went wrong. With 97 connectors needing to be disconnected and reconnected for whole harness swap, chances of similar damage goes up tremendously.

Probably easiest to put magic smoke back into damaged section of harness.

Best to order early and have on shelf before you actually need it. Due to popularity and increasing demand, might take months for your order to come in!

 

[Al st1100]

 

[Ryan_B]

Whoa, is this the actually Stevia's bike or an example of a common issue? That awesome if you made the trip to help out!

For my knowledge, anything to prevent this from happening on mine? Would adding dielectric grease to this connector be beneficial? Or just watch for symptoms/issues and correct once it happens?

Thank you,
Ryan

 

[Andrew Shadow]

Green wires are for ground. The ground wires for the front end of the ST1300 are sometimes overloaded, leading to what you see in the above picture, especially if poorly configured wiring was used for additional electric accessories that were added.

Adding an additional ground wire that runs between a good ground point on the frame and this wire shares the load and takes some pressure off of this connector.
Below is one example from Dave;
Adding a ground wire.

 

[St-Gerard]

Disconnect joint ,contact cleaner , then dielectric grease, plug back in. How often , depends on how wet a place you live in.