Engine swap and electrical upgrade

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soloracer

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OK, I have searched and have lots of bookmarked threads, etc. but I have some strictly electrical questions at this point.

I am swapping an '80 400 engine into a '77 360. I have the entire wiring harness and battery box from the '80. I have un-taped and identified the electronic ignition section and am ready to remove it from the harness. What I'm still unsure of is:

1. Where do I wire in the new harness section? I assume the red/white wire goes to the kill switch and the black to the ground at the battery box. Is this correct?

2. Do I need to remove/tape off anything from the existing loom on the bike?

3. What about the charging system. Looks like there might be an extra wire in the old connector. Someone on here mentioned "swapping alternator covers" but unless you swap the stator, I'm not sure what that would do for you.

Just looking for a little clarity and appreciate any help from the experienced here. Also, feel free to school me on anything you think I might be goofing up here.

Thanks!

For back history you can see the thread below:

http://www.xs400.com/forum/showthread.php?t=9936&highlight=400+engine+360
 
Just swap the whole harness from the 80 bike.
Leo
Went and read your linked thread. you should get the coils that go with the TCI ignition, it is TCI not CDI by the way, big difference. The points coils are like 3.9 ohm primaries and the TCI are like 2.5 ohms. A very big difference.
If you can't get the 80 wiring harness you can study the two years wiring diagram to figure out just what needs to be altered. On most of the bikes I've rewired just hook the power from the engine stop switch (kill switch to some) to red/white wires at the TCI box and to the coils.
As far as the alternator can you fit the 360 stator in the 400 case? If so use it.
Leo
 
XSLeo said:
Just swap the whole harness from the 80 bike.
Leo
Went and read your linked thread. you should get the coils that go with the TCI ignition, it is TCI not CDI by the way, big difference. The points coils are like 3.9 ohm primaries and the TCI are like 2.5 ohms. A very big difference.
If you can't get the 80 wiring harness you can study the two years wiring diagram to figure out just what needs to be altered. On most of the bikes I've rewired just hook the power from the engine stop switch (kill switch to some) to red/white wires at the TCI box and to the coils.
As far as the alternator can you fit the 360 stator in the 400 case? If so use it.
Leo
Click to expand...

Thanks for the suggestions, Leo. Tomterrific educated me on the TCI thing. I also have the coils and as I said in my post, the whole '80 harness. Swapping the harness seems unnecessary to me though. This is why I was hoping to get some input from someone that really knows the electrical systems well. I can figure out how to make it work, but would really like to understand it though.

I'll probably just do as you said for the electronic ignition. As far as the alternator, this is what I'm hoping to get a better understanding of:

'80 has 3 wire and '77 has four wire stator. They BOTH have the same 4 pin/blade connector. However the '77 harness only has 3 blades/wires in the connector. The empty slot in each connector does not match up though. What I'm thinking/hoping, is that I can just move the blade in one of the connectors so they all 3 make contact and be done with it.

Thoughts?
 
Im not sure with your specific question but I would agree to try and use the original loom because I noticed that the older model seems to have different connectors to the 79 onwards. The older ones have round pins in the connectors where the 79 on looks to have the flat spade connectors. Either way you gonna need to mod the loom to some degree but if you run the newer loom then all your switch connectors and other various older style connectors will need to be swapped out to match the newer connector types on the 80 loom. Im just comparing the NOS 400 loom I have for a 77-78 model, to an old loom from a 80 model I have and they have different connector types so arnt interchangeable without mods.
 
Greasey Fingers said:
Im not sure with your specific question but I would agree to try and use the original loom because I noticed that the older model seems to have different connectors to the 79 onwards. The older ones have round pins in the connectors where the 79 on looks to have the flat spade connectors. Either way you gonna need to mod the loom to some degree but if you run the newer loom then all your switch connectors and other various older style connectors will need to be swapped out to match the newer connector types on the 80 loom. Im just comparing the NOS 400 loom I have for a 77-78 model, to an old loom from a 80 model I have and they have different connector types so arnt interchangeable without mods.
Click to expand...

This isn't really an issue. The swap is essentially the same thing as adding electronic ignition to a points bike; i.e. a power and ground connection to the small bit of loom that connects ignitor and coils is all it should require if I'm not mistaken. Only other question is the stator but after looking at the bike and schematics, I think my plan of moving the pin in the connector should work just fine.

Tomterrific? Drewpy?

I'll report back when it's going if I don't see anymore input here.

Edit:

Sorry Greasey, I misunderstood what you were saying. You were agreeing on leaving the loom in place. I read it wrong and thought you were encouraging a wiring harness swap! I'm just not doing that. There should only be one small bit of harness to bring over for this engine. It only differs from the original in the ignition and stator and it looks like the 4th stator wire on this bike wasn't used at all to begin with.
 
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Functional progress, no. Did get the cooling fins painted and frame touched up today. Could have the engine back in frame in a day or two. Hopefully running by next weekend.
 
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So finally, she runs...purrs after a single kick most times, in fact. Still have gremlins though:

No charging

No headlight

No brake light (tail light works, so either I have no brake light or it's on all the time).


This is a '77 XS360 2E (Now with '81 400 Special power) - Apparently never had a headlight relay as far as I can tell.

As for the brake light - it seems bright, so maybe it's on all the time. I've adjusted the rear switch to no avail, not sure where the front one resides - haven't looked yet.

Not sure where to start on testing the charging system but seems to be a common issue.

I used the original rectifier from the 360 as they appear to be identical except the old one is in nicer physical condition and worked when the 360 engine ran. I used the later regulator that came with the '81 harness. Not tested, so I need to figure out how to do that and test the stator and field coil as well. I read something about a "bypass" test for the charging system? Also if I turn the key on, a razor blade should stick to the alternator cover? Is that correct?

I've been poring over the wiring diagrams of the '77 and '81 and it looks like everything is connected properly as far as I can tell at this point. So either I'm missing something or have a bad component or 2 somewhere.
 
I'll just keep answering my own questions in my own little thread world... ;-p...

Seems that the regulator would be the "what now", so that's what I'm trying to analyze now. Original reg was the mechanical type, now using the '81 reg with the '81 engine, but the '77 360 wiring harness.

So in looking at the early XS360 2F (low resolution, crappy, black/white) and 1981 XS400 (very nice, clear, color) wiring diagrams, it seems that the brown and black wires might be reversed on the regulator between these two models. By reversed, I mean the function; they are actually in the same position on the connector. Can anyone confirm or deny this with any authority? Anyone have an early XS360 2E color diagram?

Seems like this could cause my issue if it were the case - though I think I might have blown a fuse or two if the reg was hooked up backwards.
 
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So even though there is apparently little interest in this thread, I'll keep going in hopes of helping the next person.

Bike is now charging!

The regulator brown and black wires were reversed. Here's the scoop:

1977 mechanical regulator has 3 wires: Green, Black, and Black with red stripe. The plug on the 77 harness has a Green, Black, and a Brown wire. The Black/Red goes to the brown on the stock setup.

Here is where the confusion comes in. The 1981 electronic regulator has Green, Black, and Brown wires. These are the same colors as on the harness end of the bike (original 1977 wiring loom). So when I wired in the later 1981 regulator I matched the green to green, brown to brown, and black to black....wrong!:yikes: The Black wire goes to the Brown wire on the other end. Viola!Operational charging system.

I still have no headlight and no brake lights from either the front or rear switch...or maybe the brake light is on constantly, I cannot yet tell for certain. I'm really open to input on this. :shrug:
 
Dear diary,

Today I discovered that the brake light had been on this whole time. The front brake switch plastic tab had broken where it makes contact with the lever.

Maybe one of the nice folks on that XS400 forum will have a good one they can sell me. Maybe it's a fairly standard, generic part; I'm not really certain.

Until next time,

Me
 
hi there!

read over this thread... im in the process of putting an 80 harness ( complete ) onto a 79 bike. for the most part, i have everything connecting perfectly. but... in between on the harness, there is a female with 3 holes. no idea where to connect it to.

also, the 79 has only two males out of the start up coil ( above the left plug ). do you know of any bypassing?

thanks,
wayne
 
If memory serves, the 3 hole is for the electronic ignition. The 79 has points, that's why there's two males coming out of the breaker plate cover. Did you swap motors or just the harness?
 
just the harness. didn't know at the time about points and tci/tdi stuff. the more I read into it, the more I may just rewire it to what I actually want on the bike...

thanks!
 

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