Good with electrical diagrams?

My brother's '92 Sentra is the "E" model, which is the very most basic bottom of the line version. The only option the car had was A/C. The some of the upper model XE and SE-R cars have instrument clusters with a tachometer built in. I got a tach cluster at the junk yard the other day and have found that there are three plugs I have to rewire because they changed the pinout between E and XE models for some reason. Thankfully, you can just stick a real small screw driver in the connectors below each wire and release each wire and then just move it where it needs to go and it just clips back. So far I have about 90% of the cluster working, all the idiot lights and everything. But I'm having problems when it comes to getting the turn signals, tach, fuel gauge and little built in digital clock working. The wiring diagram has been great for the most part, but I am confused as to what it's trying to tell me here. To me it looks like the negative side of the bulbs for the turn signal indicators go into one wire which clips into pin 7? I have no idea. Anyone who is good with these diagrams, any help would be appreciated. I've tried a couple of Nissan forums, but if it dosen't have to do with installing a K&N filter or bolting a ridiculous body kit and wheels on, they are clueless.

 

This is where a test light can be helpful. You probobly already know but the light can be used to find hot or ground. Personaly, I would have to know which i'm dealing with (hot or ground) when I have a wire in my hand. Then I want to know what the other end, where I plan on putting it, is (hot or ground). Sorry, not much help.
Hey, just to let you know. I have seen several Nissans have broken wires in the back of the fuse box that is inside the car. Not that this is your problem, just info. Good luck.

 

Yea, my test light got broke. Came up with the idea of using my volt meter instead. Flip on the turn signal, and when I hit the right wire the voltage start pulsing up and down. So I now have the turn signal indicators and digital clock working. Right now I'm stumped on the fuel gauge and tach. Both have three simple wires, switched 12 volt, ground and signal. You would think those would be easy. Well, I've checked, double checked and triple checked the wiring, and there simply is no way that it's not right, but it's not working either.. For some reason, when I crank the car over with the tach connected, it won't start and the needle for the tach just jumps up and down a little. Last time I did it, I noticed a little bit of smoke rise up from inside the cluster. Soon as you disconnect the signal wire from the coil, the car fires right up no problem. The fuel gauge initially would just peg over to full when you turn the key on, which I traced to having the signal and ground wire reversed. Now, it just doesn't do anything..

 

You need to find out where what is on all those wires, Some may be grounds, 12v, signals, or jut loops. Do you have the diagrams to trace them out?

 

I guess I should explain in more detail what I am doing. The back of both clusters are marked (for the most part) on each trace of the printed circuit with what that wire does. So it's pretty much a matter of just moving the wire from one position, to the matching position on the new cluster. The hard part come in when you are short a few wires and the grounds are slightly different. I'm sure there are diagrams in the book somewhere, I'll have to look. The service manual for this car is over 3,000 pages.. The full body diagram for the car is on the last page, and folds out three pages wide. It's enough to make a grown man cry. It's amazing how many wires they can stuff into a little economy car.

 

Anyplace the diagram shows two or more wires going into one it means that that point or connection feeds all of the connected wire circuits. It may have a terminal where all the wires connect together or it may have the wires all going into the same connector but one way or another one wire is branching into two or more wires.