1978 Kawasaki KZ400 Fuse Short (?) and Blinker Issues Question

Hello!

I bought my 1978 KZ400 yesterday! It's my first bike and I'm learning everything from pretty much scratch, and have very little mechanical experience. It was running (I rode it in a parking lot yesterday and it switched on this morning) but the only problem I was made aware of is that the blinkers weren't working, which I understood to be a simple-ish fix from the info I had found on this forum previously. 

First thing I notice when I open up the bike this morning: no blinker relay. No worries, as I preemptively purchased the replacement off of Z1 enterprises, so I popped that in but still no dice. No clicking noise from the relay, no lights from the bulbs or the terminal. Tried switching the connections and still nothing. I also preemptively bought new bulbs (1157 for the front, 1156 for the back), as I also read that if one of the bulbs was out it could cause the circuit not to work correctly. 

The previous owner installed custom blinkers, ones that I already planned on restoring to the OEM ones he gave me, so I started switching those out.  I'm going to have to learn how to redo the terminals and I had to order a new left rear blinker off of eBay but that's not super relevant. The bulbs he were using were neither 1157 nor 1156, and they all had 3 leads each so I'm wondering if that was part of the reason why the blinkers weren't operational besides the complete lack of a blinker relay. 

The problem now is! While I was checking the bike I decided to take a look at the fuse box. I noticed one fuse (brown-white tail, I think this was the reason I never noticed the standby light on in the tail light if there was supposed to be one) was absent, so kind of absentmindedly I said "oh I'll throw in one of the spares in here" and as soon as I did the fuse box got really hot, the fuse in question welded itself to the connector, and the lights stopped turning on when I put the key in the "on" position. The bike was off, but the battery was still connected. I have the vaguest feeling this is not supposed to be the outcome of this particular action. 

I did manage to pry the fuse free. My working and completely guesswork theory is that there's a short in that tail circuit somewhere that resulted in me inadvertently draining the rest of the battery. I'm planning on picking up a battery charger and volt meter tomorrow to see if I can get the bike to start at the very least, but whatever happened with that fuse is going to have to be fixed if I want to do any night or otherwise low-visibility riding. 

My questions are as follows:

Where should I look to identify potential causes for this short?

Would I be able to fix this on a limited budget with limited experience/skills, or should I have it looked at by a professional?

Any insights on the blinker issue and whether or not my proposed solutions might work once I have the battery tomfoolery sorted out?

Also, there's a loose wire hooked up to the frame that I'm assuming is a ground wire above the battery? What is that supposed to look like, if anything?

Any other additional insights?

I'm currently located in the Bloomington area; any assistance is greatly appreciated! Also let me know what other information would be needed to start to solve this issue. Please be nice to me as I am still completely green in all of this!

Cheers and best, 
Thel

 

Check out this thread for diagnosis of blinkers on a 400

www.kzrider.com/forum/4-electrical/62005...z400?start=36#896340

I'll give it a shot later today.Just driving around right now.

ok, when the rear tail light bulb is not plugged in and the brown wire white stripe fuse is in place, Which lights light up?
oil pressure light?
neutral light?
speedometer light?
tach light?

I replaced the main fuse and got the bike running again (thank god!) and I replaced the thermal relay with an electric one so here's what works and what doesn't:

Works:
All the stuff connected to the main fuse
Headlights/High beam/high beam indicator (it's a tad dim but it definitely lights)
Neutral and oil lights
Stop light 

Doesn't:
Tail light 
Tail light indicator 
Blinker indicator does not turn on, no blinks or solid lights
Blinker relay still doesn't click

Would the tail light and the blinker relay be connected to the same fuse? I noticed they shared a connection on the wiring diagram. Maybe not having all the bulbs connected didn't offer enough resistance and blew the relay? Any thoughts?


​​​

OH I misread your question, I still have to go back and pick up a few 10A fuses but I might be able to check that later tonight. 

Wait....Is your brown/white fuse not installed?
And all of these lights are working?
nevermind

the brown/white fuse controls the following:
front right and left position lights
speedo light
tach light
rear tail light

Turn signals are on the brake light circuit which would be the main fuse

Yep, I haven't reconnected the tail light fuse since it blew the main one last time. So that probably means there's some sort of tomfoolery happening on both circuits? If the blinker relay (double checking, is the yellow and brown wires near the regulator on the right side??) isn't connected to all four bulbs, would an electric one still click? I've confirmed (but I'll double check to make sure) that there is indeed a voltage going to the relay, but I'm gonna go back and make a more thorough check.

Any advice on how to check for what might be going wrong on the tail light circuit, then? Meanwhile I'll start digging through the manuals and youTube.

So when you put the brown/white wire fuse in place, it blows the white wire fuse as well as the brown/white fuse?

I have a feeling the turn/position lights are not hooked up properly. They should work without the brown/white fuse in place.

I haven't tried replicating the issue yet (I'll have more time tomorrow) but that is what happened the first time, yeah.

​​I'll be checking the manual and what sources I can find (I'll scour through the link that was provided in the first reply) to find out where the blinker connections are set up and what they're supposed to look like.

That main fuse (white wire) should be a 20 amp fuse. The other ones are 10 amp. Get quality fuses from a reputable source(no amazon or ebay).
The brown fuse should have blown first as it was lower than the main fuse.

The blinker circuit is pretty easy.
But I have a feeling the lights may not be hooked up properly.

ok, I have the day off so I can write this up.

You'll need to pull out the light bulbs marked with the green circle.
They will show a path to ground and we don't want that when taking readings.

Disconnect the ignition switch connector marked with green circle (possibly inside headlight bucket).

Put your meter on DC V
red probe on positive post on battery.
black probe on the red/blue wire in the fuse box.

You are aiming for a 0.0v reading that fluctuates very close to 0.0v.

With a short, the reading will be significantly above 0.0v up to battery voltage.

Most likely with the bulbs removed you will still see battery voltage indicating a short in the wiring.

There is a second picture with blue circles.
While watching the meter pull each connector with a blue wire within the blue circle.
If the meter reading suddenly drops to 0.0v then you have found your short.

If you have pulled all connectors and the reading is still high, then your short is in the main part of the red/blue wire circuit.
You may have physically open the loom to find that short.

There is a possibility that the short is in the taillight circuit, but we'll check this circuit(red/blue wire) first.




 

 

Okay so I installed the new blinker bulbs and reconnected all the terminals and still no dice (photos included if you feel inclined to double check my work). I have confirmed that there is a constant voltage as I am fairly sure there is supposed to running to the relay but there's also a constant voltage running through the relay to the yellow L wire regardless of the switch position-- could this be related to the short? 

With all the fuses installed there was battery voltage running through the blue/red wire and I've tested all the terminals but the one connecting to the brown wire in the headlight bucket. I still need to root around and find where that one connects. There's also a stray brown wire with one of the double connectors in the headlight bucket that I'm not sure about the purpose of. 

What do I do if this ends up being in the loom? Do I just remove the gas tank and scour the harness until I find the problem?