Electrical issue
 

Ey guys, looking for some hints here. So Im finished with my full motor rebuild on my 1978 L28e everything mechanically is perfect. However, there is a weird click somewhere in the center of the dash console. The weird part is that it only clicks when I put in a fuse for the horn (Fuse 12A on the fuse box I think) and eventually drains my battery and blows the fuse. The other weird thing is that my combination switch works except the turn signal switch. It isn't receiving any power and neither are my windshield wiper arms? I have done a bunch of continuity tests and everything seems fine. My switch is good the fusible links are good and the wiring hasnt been messed with. Im gettin frustrated :088: so was curious fr some hints where else I can look at. I will continue busting my head on this any input is VERY appreciated thanks fellas.

So this all started after pulling & installing the motor?
Have you tried pulling the horn relay, wiper relay, and/or flasher relays to see if it still pops the fuse / drains battery?

Yeah actually the wipers did stop working after motor so I bought a used motor for the wipers but the turn signals always never worked so i got a different switch but still acts the same. Nope haven't tried that yet because once I take the horn fuse everything works fine but I will try that tomorrow. Thanks NismoPick.

I wouldn't recommend driving around without that fuse in. It also is the power for your brake lights.

Unless someone hacked the dashed harness, the horn fuse only branches to the brake lights and the horn relay. If the brake pedal does not press on the brake light switch or if the brake light switch is broken, your brake lights would stay on, and that would drain your battery.

I would unplug the horn relay and check your brake lights when the fuse is in.

Ok. Im going to try that tomorrow. Quick note though, the brake lights work fine. :confused: I guess best bet is to see if they did mess with the wiring harness in the dash because they ran an orange wire from the thick white with red stripe wire going to the ignition relay? WHY? I don't know, but i remember that the relay would shock me when I tested it. I think this explains why after driving the car the voltage on the battery is good but its hard to re-start the car.AHHH. Thanks so much NismoPick. Ill keep you posted after I try the no relay method.

It's not unusual to find a hacked up wiring harness. A previous owner doesn't understand the wiring diagram, so he just connects wires until it works, usually by using only a voltmeter to confirm suspicions.

Yeah maybe that might be what happened here. Thnks for the input fellas.

So i worked on the car today and I had confused the horn fuse with the lighter fuse so I fixed the short on the lighter. I also tested my wiper motor and is bad. Now the only problem left is the turn signal switch and the weird trouble when restarting the car while hot. I did a continuity test on the signal lamp switch and everything came out fine so apparently no one has touched the dash harness. I might be doing something wrong here but will the turn signals show on the dash even though I have none of the turn lamps connected to a bulb? Thanks for the input NismoPick.

IIRC (been a while since I've driven my Z with a turn bulb out), if a turn signal bulb is burnt out, the dash arrow will just stay perma-lit while signalling.

Also, check the hazards switch to make sure it is fully OFF. The 280zx has a notorious faulty hazards switch that will screw w/ the turn signals. :D

How did you test it?
What is wrong with the switch? I have a pictorial on my blog on how to clean it. If you can't clean it, I'm sure I have another in my big box of turn signal switches.
Can you give more details on this? Hot restarts are frequently due to a failing coil or failing ignition box.
If you have stock type flashers, they operate by heating up a bimetal strip. Hit your turn signal, and the current starts flowing and heating up the strip. The strip heats up enough to move, and the circuit breaks. The strip cools back down and makes contact again. With only the dash lights, I doubt there is enough current flowing to heat up the flasher.
If you have an electronic flasher, the turn signals could blink even if you only have bulbs in the dash.

Unfortunately you're leaving out a lot of details, so it makes it a challenge to offer a good diagnosis.

To NismoPick: Ok, I have tried the hazards and they have bad contacts. However, they work perfectly fine when I adjust the contacts. Which is why I thought the signal lamps not having a bulb shouldnt be a problem. But Im going to try it putting them on. Thanks NismoPick.

To Steve260z74: I have tried the stock flasher and an aftermarket one. But honestly, I feel like the problem is, that it isnt having power to send to the switch because I couldnt find continuity when testing it with a volt-meter light. Thanks tomorrow I will check the book for which wire is the power source. Thanks a lot guys. I appreciate the help.

The 78 FSM has a very good breakdown of how the circuits are for the turn signals and hazard light. It even includes what connectors are used, etc. I suggest you look there to trace your circuit.

I have tested them for continuity and the continuity was good. I have cleaned the combo switch including the turn signal switch before the continuity test. The indicator lever wont blink or do anything when pulling to the down position(left turn) or up position(right turn) but if I use it to get the high-beam mode, it works fine.??? I have tried my original one and a used one a buddy gave me.


Now that you mention this coil and ignition box you have me wondering. Because my starter went out two days ago and i replaced it. after I replaced it the battery was getting drained also. I have however a new coil and new alternator so I cant say those are the suspects. idk i guess I have a big electrical mess. :009:

I have stock flashers. It cant be the flashers though because I have tried new ones on the turn signal switch and it still wont do a damn thing...

What details am I leaving out?

I'm terribly sorry I missed this message earlier Steve260Z74. Please respond when you can this problem is frustrating.:009: Thanks guys.