breathing life back into my 81, wiring headaches

So... she's back together, engine in the frame, all the remaining electrics buttoned up and on, oil system full and primed, plugs in, wires hooked up. When I push the "go button", I don't get any response from the bike. No spin, sputter, cough, nothing. I can spin the motor over by jumping the starter solenoid (thats how I primed the oil system after filling) but for the life of me I can't figure out why the starter button doesn't do a thing! I've been looking over the "XJ minimum wiring diagram" that I found here: http://xjbikes.com/Forums/viewtopic/t=1 ... art=0.html

And it seems that the headlight and tail light are both "checked" so to speak, before the starter switch will work? I don't have either of those on the bike yet. And, when they do go on, they'll be wired alot more simply, as I'm trying to cut down on the rats nest of wires on the bike. Any suggestions on how to bypass them in the "factory" harness to get my starter button to work again?

 

Have you ensured that you don't have the Kill Switch on or the wires pinched? That is how I got my Max cheap!
The bike should start with either the head light or tail light out so I don't think that is your issue. Another possibility is your ignition switch. The switch contact plate could be broken and this will also cause your symptoms.
Let us know what you find.

 

Well, the ignition seems to be fine (and was fine before I took everything apart.) So I don't think that's the issue. The kill switch seems to be fine, again, was okay before hand and I haven't messed with it.

So I should be checking my right-hand control-pod wiring before anything else?

 

I would check as you have nothing to lose and it's free.
I would pull apart your starter switch and have a peek at it's material condition. Corrosion on the back side of the button and the contact is common.

 

Does the solenoid click at all? Could be your button like Robert mentioned or your Solenoid could be bad or wiring for button to solenoid.

you can check your button at the solenoid - see if you get 12v on the terminals for the button when it is pressed or unplug and check continuity of the wires and button operation. At least a place to start.

 

Okay, I'll definitely be doing that this afternoon then. I do have drag bars on the bike, which makes getting the controls onto the bars a bit interesting, as theres quite a bit of extra wiring, so it is entirely possible I got something pinched.

Anyone got any other ideas of stuff to check while I'm at it? I'm hoping its just something simple, but yeah. My luck, it usually isn't.

 

Okay so... I rode the bike yesterday . Only a couple laps around the block since I don't have any of the trim/lights on yet, but better than nothing!

The starter button still doesn't work. Kill switch does though. I whipped out the multimeter and checked for voltage at the starter button, no dice. So I have some kind of wiring issue there.... We tried to trace the wiring through the harness, but shortly after joining the main harness, all the wires from my control pods turn into plain brown wires, so the job got ... interesting. Does anyone know what color the right wires should be? Coming out of the switch (inside the pod) is a blue/white wire, and a black wire, but I couldnt seem to find them further back on the harness.

 

The starter switch should have the following on an 81 750 Seca:
black/white and black.
Black/white is routed from the starter solenoid. This in turn (that is kinda funny if you understand how a coil works) is fed 12V from the red/white wire on the other side of the solenoid connector and that gets it's power from the Starting circuit cutoff relay.
Black is system ground.
You ought to make an investment in a manual for your machine, best money you will ever spend on it. the schematic in my beloved Haynes is worth its weight in gold.

 

Amen to the Haynes manual comment...
I think I may buy another one as my first one is getting worn out!
It should be a prerequisite for joining this forum...

 

While I may be biased toward my venerable old Haynes (I'm in the same boat SirHedgehog, worn out my garage copy), it should be said that any service manual should be a prerequisite for wrenching or asking questions. I'm not terribly impressed with the arrangement of the factory manual (though the photos make it worth the investment) and early Clymers left a great deal to be desired. The XJCD is the best deal going as you get everything from the factory but requires a computer.

 

I have the XJCDs, but its hard to make heads or tails of them most of the time. I've decided that I'm just running my own new starter button and ignition switch (hidden) so those wire colorings help me out a ton Robert, thanks!