Complete Re-wire

[joelnaf]

Ive had my 240 for almost 2 years now and I have numerous electrical problems. The fuse box heats up to the point it melts. The wiring under the dash does the same. The more i tear into the wiring the more crazy it becomes. The Harness is real piece of art. Thousands of different color and gage wire, Millions of random connections and plugs that go no where. At this point i don't think there is any point in trying to save it. The problem i am having is trying to find a new harness. Is there a company that makes a complete harness for the 240, or do i have to use the universal kit?

Thanks for the help!

[Fuzzydicerule]

You and i are in the same boat man. I was planning on using a universal painless 12 circuit. I was not planning on using amy of the stock switches, but im sure you could wire it up with them if you had the patience

 

As far as one made for the car, ive been looking but have had very little luck finding anything..

[mutantZ]

I think its either used, tuning shop, or DIY for the harness. You might try Eric for a used harness in good condition. He seems to have a ton of Z stuff, nice guy to boot.

 

http://www.zparts.com/

[Miles]

Most people use the Painless kit which has been written up extensively here. There is a thread that explains how to connect the Painless kit to the combination switch. There are also write-ups on other kits as well. I have never heard of an after market stock wiring kit so Painless (or other brand) kit is the way to go.

 

There are a number of good write-ups on the ClassicZ website too.

[rsicard]

Ive had my 240 for almost 2 years now and I have numerous electrical problems. The fuse box heats up to the point it melts. The wiring under the dash does the same. The more i tear into the wiring the more crazy it becomes. The Harness is real piece of art. Thousands of different color and gage wire, Millions of random connections and plugs that go no where. At this point i don't think there is any point in trying to save it. The problem i am having is trying to find a new harness. Is there a company that makes a complete harness for the 240, or do i have to use the universal kit?

Thanks for the help!

 

I have a 240Z also and have to do something with the wiring. The weaknesses in the wiring are the mechanical connections and the switches. Nissan routed heavy electrical current through the steering stalk switches for the headlights and running lights. The headlights have two fuses. One for the left headlight and one for the right headlight. That aspect of it is GOOD in that with one fuse blown both headlights DO NOT go out. The bad thing about it is the heavy electrical current for the headlights runs through the switches on the stalks on the steering column. To overcome this DESIGN DEFECT insert relays in the positive or negative side of the headlight wiring and have them controlled by the stalk switch which has to handle MUCH LESS electrical current. Then have Dave (on classiczcars.com) in Washington state rebuild the switches for you. Then the system will be BETTER than new. Also replace the running and turn signal bulbs with LED replacements from Superbrightleds.com. They may be expensive but should last much longer than incandescent bulbs.

 

Additionally, I found BAD single contact male and female connections in the harness on the cabin side near the firewall by pealing back the wrapping on the harness. Then cut off the blade type connectors, stripped the wire, slipped on heat shrink tubing, twisted them together and soldered them with Rosin Core solder and then slid the heat shrink over the connection and shrunk them with a heat gun from Harbor Freight. The other area that may need attention is the underside of the fuse panel. Perhaps some soldering will reinforce or strengthen connection there also. All the above is easier than replacing all the harnesses. Just some suggestions.

[Miles]

I have a 240Z also and have to do something with the wiring. The weaknesses in the wiring are the mechanical connections and the switches. Nissan routed heavy electrical current through the steering stalk switches for the headlights and running lights. The headlights have two fuses. One for the left headlight and one for the right headlight. That aspect of it is GOOD in that with one fuse blown both headlights DO NOT go out. The bad thing about it is the heavy electrical current for the headlights runs through the switches on the stalks on the steering column. To overcome this DESIGN DEFECT insert relays in the positive or negative side of the headlight wiring and have them controlled by the stalk switch which has to handle MUCH LESS electrical current. Then have Dave (on classiczcars.com) in Washington state rebuild the switches for you. Then the system will be BETTER than new. Also replace the running and turn signal bulbs with LED replacements from Superbrightleds.com. They may be expensive but should last much longer than incandescent bulbs.

 

Additionally, I found BAD single contact male and female connections in the harness on the cabin side near the firewall by pealing back the wrapping on the harness. Then cut off the blade type connectors, stripped the wire, slipped on heat shrink tubing, twisted them together and soldered them with Rosin Core solder and then slid the heat shrink over the connection and shrunk them with a heat gun from Harbor Freight. The other area that may need attention is the underside of the fuse panel. Perhaps some soldering will reinforce or strengthen connection there also. All the above is easier than replacing all the harnesses. Just some suggestions.

 

 

Dave also makes and markets a plug and play headlight relay harness. He sells it directly (see vendor section) or you can get it at MSA. The harness takes about 20 minutes to install, takes the load off of the light switch and the lights are much brighter.

[GOTHALOSISM]

This place sells a universal kit that is alot cheaper than painless. I'll probably go this route as soon as I get some other things first.

 

http://www.ezwiring.com/wiring_harness.html

[240ZZ]

I have been there and done that. Do not buy a prewired universal kit. Get the wire fuse box seporate. This way you can get the correct length of wire were it needs to go with out splicing. I bought the 18 circuit kit from painless. You don't need that many circuits. I mounted the fuse pannel on the passenger side firewall. I used the original connectors. I will send some photos this weekend. Also go to ebay and get the color wire diagram 11X17 cant tell you how much that helped. My 1970 240Z has been on the road for 3 years with no electrical problems. I also converted to single wire alternator. This was the first time I have ever wired a car. So if you know a little about wiring it can be done.

[rsicard]

I have been there and done that. Do not buy a prewired universal kit. Get the wire fuse box seporate. This way you can get the correct length of wire were it needs to go with out splicing. I bought the 18 circuit kit from painless. You don't need that many circuits. I mounted the fuse pannel on the passenger side firewall. I used the original connectors. I will send some photos this weekend. Also go to ebay and get the color wire diagram 11X17 cant tell you how much that helped. My 1970 240Z has been on the road for 3 years with no electrical problems. I also converted to single wire alternator. This was the first time I have ever wired a car. So if you know a little about wiring it can be done.

 

With the Painless kit, what was done with the turn signal, high/low beam, headlight, wiper and washer switches stalks on the steering column? I am faced with fixing up the wiring on my 71 240Z. After studying the wiring diagrams the fixup solution is not all that bad. Purchased a separate fuse panel which will be positioned where the original is but has a better capacity. Also want to update running and turn signal lamps to LED types and the turn signal and emergency flasher need to be replaced with modern types to handle the LED bulbs. Designed a rewire of the headlight circuits to add relays to take the heavy current off the stalk switches which fixes the design deficiency of the original circuits. The same needs to be done in the ignition key on circuit by adding another relay.

[240ZZ]

With the Painless kit, what was done with the turn signal, high/low beam, headlight, wiper and washer switches stalks on the steering column? I am faced with fixing up the wiring on my 71 240Z. After studying the wiring diagrams the fixup solution is not all that bad. Purchased a separate fuse panel which will be positioned where the original is but has a better capacity. Also want to update running and turn signal lamps to LED types and the turn signal and emergency flasher need to be replaced with modern types to handle the LED bulbs. Designed a rewire of the headlight circuits to add relays to take the heavy current off the stalk switches which fixes the design deficiency of the original circuits. The same needs to be done in the ignition key on circuit by adding another relay.

 

The painless kit had the power wire +B going to the switch. Datsun switch is a grounding one. +B feed goes to the headlight and the two grounding wires go to the switch. Same with the wiper. Not sure about the LED I have stock on my 240.