GPZ 550 Wiring Nightmare

Well this is a nightmare for me because I have little to no electrical knowledge or experience. So I'm going to be needing a lot of help. I have a GPZ 550. The motor is from an '81 GPZ D1 and the rest of the bike including the wiring harness is from an '81 GPZ H2. I have a wiring diagram and I think I have all the proper wires connected. I however can only get the headlight and horn to work. The only way that I can get the starter to work is to connected a wire from the positive stud on the battery right to the starter lead. What are the major differences,if any, that I will encounter between the two years? Anyhelp would be greatly appreciated.

Thanks,
Nate

If you know hydraulic or pneumatic systems the wiring is pretty much analagous. Even to the point of transistors being similar to fluidic(not sure if this term is still in use) valves.

-Duck

Shoey949 wrote:

I have a GPZ 550. The motor is from an '81 GPZ D1 and the rest of the bike including the wiring harness is from an '81 GPZ H2.

I think the gpz 550 H2 was an '83.

The D1 was the only gpz 550 in '81.

Post edited by: loudhvx, at: 2006/01/24 06:39

If you have wiring diagrams, then you can figure this thing out. Essentially, the solenoid/starter system works like this...

There is a direct power wire from the battery to the solenoid which is essentially, a switch. From this solenoid is a power wire to the starter. To make the switch close, power has to hit the solenoid. The path of the power is from the fuse area to the ignition switch through the kill switch and then back through the wiring harness to the solenoid. Note that the headlights and horn are ALSO on switched power following this path so it makes sense that if the lights work, the trigger for the solenoid should work as well.

In the early 80s, safety was becoming more of an issue and some bikes had switches on the clutch and sidestand to keep them from starting. This switch must break the path I described in the previous paragraph. See if the donor wiring harness accomodates these safety switches. It could be that there are wires that need to be bridged to fool your wiring (be closed/pass voltage) if these devices are not present on your bike. The clutch interlock will have wires that connect to the left hand switchgear and the kickstand will have wires down by the kickstand.

Just a theory but I think it makes some sense.

Well I don't have a sidestand switch it is supposed to have one, so that might be part of the problem. Sorry Loudhvx, I meant to write '83 just came out the wrong way and I didn't correct it.

How exactly would I cross the wire up if I don't have the switch, what would I connect it to?

Well, I've been able to do a little work on the wiring, but have made no real progress. It appears that I have a couple of bad starter relays. There was a new-looking one on the bike when I bought it, and what looked like the original in the spare parts box. I tested the voltage coming from the leads that would hook up to the relay and they read just like the should. Then I hook them up the the relay and nothing, not even a click, from either of them.The starter motor does work though. Is their something I could be doing blatanly wrong? What would cause relays to fry like that?
Thanks,
Nate

Maybe pull in the Clutch while turning it over?

(I am saying this Humorously too) But it may be the problem, There is a switch in it on mine and I just jumpered it to void it all the way without much effort.

i wouldn't be getting voltage to the relay if their was some switch interfering.

Voltage goes to the relay from two places. 12v goes to the relay CONTACTs from the battery directly (through the heavy cable). 12v also goes to the relay COIL from the starter switch through an interlock switch. One is on the clutch lever and your model may possibly have others.

If you are getting 12 volts at the coil every time you press the starter button (engine kill switch must be on and key switch must be on and fuses good etc), then you should make sure the other side of the relay coil is grounded.

what do you mean the other side of the relay coil? The stud that the starter is connected to?

Shoey949 wrote:

what do you mean the other side of the relay coil? The stud that the starter is connected to?

No. The starter relay (on KZ's) should have 4 contact points. 2 (big heavy contact bolts) are for the relay contacts, and 2 (wires) are for the relay coil.

The two for the coil should be a black wire (positive side of the coil in this case) and a black/yellow wire (ground). It's possible that the wire colors are different on your model. i have come across a few different colors. on the 82/83 550 F models, the ground wire is red/yellow. Yes, the red/yellow wire is grounded as crazy as it sounds. However, it really doesn't matter which is which since the relay coil doesn't have a polarity.

The starter button feeds 12 volts to the positive side of the relay coil through the clutch lever switch. The relay coil's negative side is always grounded.

Post edited by: loudhvx, at: 2006/02/08 19:36