Electrical Pleague

[red_dog007]

Ok, so, I have the electrical pleague. Headlights, side corner lights, brake lights, and my wipers do not work.

I am mostly worried about my headlights, and I have rechecked and doubled checked everything. Basically, is my steering wheel control unit dead? When I turn the lights on, all I get are my front blinker lights, and my tail lights.

For the headlights, I have tried new bulbs, messing with wiring, double checking wireing to see if there are no cuts, ect. ect.

I got the wireharness thing off blackdragon, and for at least the 240z, do not buy it unless you want to do a lot of wire cutting and fitting.

Is there any place to buy a completely new wireharness for the 240z? I just want to replace it all. I feel like with these 30+ year old wires, I am not going to be having a lot of fun with them.

Also, for the headlights, is there some kind of way that I could rig it up to were I do not need the steering wheel switch? I don't care if I have to pull over to attach/disconnect to get the lights on/off.

Also, could I take the headlights and hook them to the front blinker wiring?

[MikeW]

Did all of these things quit suddenly? It's not so much the 30 year old wires but rather the 30 year old connections between wires. When multiple things fail at once it sounds more like a fuse or fusebox issue.

[geezer]

I have been following your efforts to get your car roadworthy and make the long trip home and I hope you are successful. It is admirable that you are making the effort to correct the electrical problems, but you should go about it the right way. There is a correct sequence to follow when trouble shooting electrical problems. You can't just keep making guesses and add new parts such as the BlackDragon harness. You must first correct the existing wiring or at least diagnose the problems. I know none of this seems to be of any value to you and is not giving you any answers, but if you take the time to learn a few basic electrical trouble shooting skills, the time will be paid back to you a hundred fold in the future. Without being there and having a hands on advantage it is difficult for anyone to diagnose these problems online. I'm going to repeat some tips I posted recently. This is all you need to know to find and repair most electrical problems on these cars.

In order to diagnose an electrical problem you first should have a thorough understanding of how the system operates. There is no better way to do this than studying the wiring diagrams and understanding the components involved in a particular circuit. Visually check the connectors & harness in this circuit. Try gently manipulating the connectors to expose a temporary power outage or loose or poor connection due to corrosion. On cars this old it never hurts to check the integrity of the terminals and clean them. If nothing obvious turns up, use a digital multimeter set on the resistance function to first do a :

Continuity Check (open in the circuit)

1. Disconnect the battery negative cable

2. Start at one end of the circuit and work your way to the other end ( at the fuse block in this case)

3. Connect 1 probe to the fuse block on the load side

4. Check each subsequent point along the circuit with the other probe

This should point out a blown fuse, loose or corroded connector or a break in a wire.

Or use the

Voltage Check method (battery connected)

1. Switch the multimeter to the voltage function

2. Connect one probe to a known good ground

3. Begin at one end of the circuit and work your way to the other end checking for the proper voltage

Shorts

With the negative battery cable disconnected you can test for shorts in the circuit by connecting one probe of your multimeter (set on the resistance setting) to a good ground and the other probe on each segment of the circuit, broken down to increments by disconnecting connectors or relays. The goal is to isolate the circuit in order to narrow the search for a short. The beep indicating continuity will point out a short.

Grounds

I can’t stress enough the importance of ground connections. Dirty or corroded connections are the cause of unwanted resistance, severely changing the way a circuit operates.

These are just a few basic tips that can be used on just about any circuit on these cars. As I said earlier the first thing you need is a good understanding of the circuit in question and that means a good wiring diagram. Good Luck

PS - Avoid using your test light instead of a digital multimeter if there is any chance of letting the smoke out of computers or sensitive controlers.

[SteveJ]

Too bad you're not still in Chattanooga. I'm only about two hours away. I'm pretty familiar with 240Z wiring, having done many repairs to my own car.

[JimmyZ]

Geezer's advice is excellent as he has a professional background in automotive electronics. Time to pop out a multimeter and poke around. Get a set of jumpers (alligator clip & wires) from radio shack for supplying 12v to certain leads once you have gone over a schematic.

Check your connections on the steering column harnesses. Unplug and re-insert one at a time to see if that helps.

If the contacts in your light switch are corroded you might be able to get them to work by tapping on the electrical box at the base of the switch. There have been numerous posts on how to take apart and clean the contacts inside the switch.

I'm betting it's your switch or a harness plug going to it.

There have been several discussions RE getting/making harnesses. It seems that the connectors are too rare and unobtainable to make new harnesses from. That leaves you with buying used harnesses or getting a generic harness. There have been many threads discussing this too.

I had talked with some other members about working together to make 240Z generic harnesses. It seems that there are a few differences which would require different sub-harnesses such as the tach. Any such harness would require a some degree of cutting and splicing on some things.

2c

Jim

[JimmyZ]

BTW unplug your side marker lights each and every one. Unless the are new they often corrode and short. Try and get the headlamp thing sloved first. (duh)

[justinr54321]

What I did to fix my headlight problem for now was buy a project box and 2 12V, 20A automotive toggle switches from Radio Shack, and installed the switches into the box, and ran the 2 wires from the headlights to one switch and the wires from the parking lights to the other. 4 wires in all. Just take the wires from the combo switch, extend them and attach them to the toggles. Make sure you are running the 20A fuse in the fuse box at the same time.

With me, I'm buying the upgrade harness from Zs-Ondabrain in the next couple of weeks so I may put on my new steering column cover and new combo switch.

Justin

[JimmyZ]

Here's a quick test I did which might help you red dog...

This is on my 2/71 240... With the steering column cover of you should see 4 solder connections on top of the light switch. The upper left and lower right connections/wires should always have current. (Lower right is a white w/ red stripe) When you switch the running lights on the left two connections are live. Switching the head lamps on the right two come alive. (Actually all 4 connectors have voltage) Left side is running lamps. Right side is headlights.

There are two fuses in the upper right side of your fuse box for the headlamps.

2c

Jim