Included here is a "minimum" wiring diagram. This is good enough for a racer, and good enough for a minimal street car (daylight, no rain). I'll be building up the diagrams bit by bit over time. I'm not following the OEM wiring colors exactly, as I'm not going to use "tracer" wire (too hard to get in small quantities). But the general scheme will be the same.
This diagram shows my car as it sits now, and it starts and drive (carbs, btw). The next diagrams will show things like gauge hookups, lights, misc, and EFI. I'll also be posting tips on constructing your own harness, like which connectors to use, tools, techniques.
Full Version: Rewiring project thread
I thought it was illegal to not have operating windshield wipers on a street vehicle originally equipped with them??
When removing the OEM harness, it all needs to be pulled "towards" the fusebox. Everything should be disconnected in the front trunk (lights, horn, headlight motors, wipers, front blower) and all of the wiring pulled down through the grommeted hole near the left A-pillar, directly in front of the driver. The rear trunk wiring should be disconnected and pulled towards the relay board. The relay board should be disconnected and removed. The wiring from the various bits of the engine to the 12-pin connector on the relay board (the one towards the rear of the car) is completely separate. The section from the relay board and battery forward has to go down through the hole in the front engine shelf, then forward through the firewall and the center tunnel.
The wiring behind the dash disconnects at or very near the steering column. For the early cars, there's one big connector hidden up behind the dash that looks like a relay board connector. This is mounted with a slot connector to the dash itself, to the right of the steering column. On the later cars, there are several connectors at the bottom of the steering column. The wires from the heater controls are all just spade terminals.
You'll be tempted several times to just pull out the snippers and start cutting wires. If the wire insulation is still flexible and not horribly faded, the wire can be reused in a new harness, so try not to cut it. New wire is quite pricey. Proper automotive grade (heat and oil resistant insulation) wire can easily run $300 or so for enough in enough colors to complete a harness. Connectors, however, generally should be discarded, so don't feel too bad about cutting off connectors you can't feed through a hole.
The wiring behind the dash disconnects at or very near the steering column. For the early cars, there's one big connector hidden up behind the dash that looks like a relay board connector. This is mounted with a slot connector to the dash itself, to the right of the steering column. On the later cars, there are several connectors at the bottom of the steering column. The wires from the heater controls are all just spade terminals.
You'll be tempted several times to just pull out the snippers and start cutting wires. If the wire insulation is still flexible and not horribly faded, the wire can be reused in a new harness, so try not to cut it. New wire is quite pricey. Proper automotive grade (heat and oil resistant insulation) wire can easily run $300 or so for enough in enough colors to complete a harness. Connectors, however, generally should be discarded, so don't feel too bad about cutting off connectors you can't feed through a hole.
QUOTE(Mueller @ Sep 19 2005, 03:13 PM)
I thought it was illegal to not have operating windshield wipers on a street vehicle originally equipped with them??
I'm sure it's illegal to not have headlights, either...This isn't about legal, it's about enough to drive around and not get instantly pulled over for no brake lights...
Wipers (and headlights, and everything else) are on the way, one bit at a time...
| QUOTE (lapuwali @ Sep 19 2005, 04:20 PM) | ||
I'm sure it's illegal to not have headlights, either...This isn't about legal, it's about enough to drive around and not get instantly pulled over for no brake lights... Wipers (and headlights, and everything else) are on the way, one bit at a time... |
my bad
I read it as if you are deleting them totally...
I look forward to seeing project
This diagram is of the charging system. Pretty simple. One thing that is required is the G lamp. If this is left out, the alternator will not work.
Note the thickness of the lines indicates (roughly) the wire gauge required. The gauge from the battery to the alternator itself has to be quite hefty (3 or 4 gauge). Up to 55amps of current flows through this wire, and 20+ amps is a pretty common level of current here.
Note the thickness of the lines indicates (roughly) the wire gauge required. The gauge from the battery to the alternator itself has to be quite hefty (3 or 4 gauge). Up to 55amps of current flows through this wire, and 20+ amps is a pretty common level of current here.
Great thread James...very helpful. 
Do you have any experience wiring up 911 CIS in a 914?
Do you have any experience wiring up 911 CIS in a 914?
Here's a general lighting diagram. I'm not including turn signals, which will be a separate diagram.
I'll be putting some detail on how to use relays in a later post. The idea on this diagram is to put the relays for the front-mounted lights and horn in the front trunk, since that shortens the wiring runs for large-gauge wires. It's also assumed the stock headlight switch is used, as it's a very nice switch, even if it has 8 zillion terminals on it. If your switch is dead or missing, you can get a replacement at a Bug shop that has only 6 terminals on it, and costs only 10% as much as the 914 switch ($30 v $300, no kidding).
No parking lights are included here, so this arrangement wouldn't make the German authorities happy, but it would get past the US authorities. Adding "side lights" (turn and side marker lights) could be easily wired in to the low-beam circuits, so they'd come on if the regular lights are on.
For high beams, one could use the first position on the stock switch as low beams, and the second position as high beams, and wire it all up as shown here. I may put together a variation including the stock system of using the momentary switch on the stalk and the stock latching relay. This same system is used on many VWs, so the column switch and the relay are readily available cheaply.
Finally, this circuit will allow fog lights to be turned on any time the car is running, not just when the low beams are on. This is a commonly asked for "upgrade", and it's simple to do. To make the fogs work as stock, just replace the black power in wire at the fog switch with another yellow low-beams wire, powering the switch from the low-beams signal.
In the diagram, HLmSW is the "wiper" switch in the motor itself. Rm is the motor relay, which is found under that plastic cover near the motor in the stock setup. It's a standard 5-terminal relay, and the small numbers are the post numbers on the relay itself. A standard "square" 5-terminal relay could be substituted here, if your round relays are missing or dead.
I've not numbered the other relay terminals, because they're "standard", in that 85 is the switch power, 30 is power in, 87 is power out, and 86 is grounded. 87a isn't used (if you use 5-terminal relays), except on the low beam circuit, as part of the motor circuit.
I want to thank Clay Perrine for his headlight motor circuit diagram (in the Classic threads section), as it saved me the trouble of working out how the bloody thing worked by squinting at the wiring diagrams.
I'll be putting some detail on how to use relays in a later post. The idea on this diagram is to put the relays for the front-mounted lights and horn in the front trunk, since that shortens the wiring runs for large-gauge wires. It's also assumed the stock headlight switch is used, as it's a very nice switch, even if it has 8 zillion terminals on it. If your switch is dead or missing, you can get a replacement at a Bug shop that has only 6 terminals on it, and costs only 10% as much as the 914 switch ($30 v $300, no kidding).
No parking lights are included here, so this arrangement wouldn't make the German authorities happy, but it would get past the US authorities. Adding "side lights" (turn and side marker lights) could be easily wired in to the low-beam circuits, so they'd come on if the regular lights are on.
For high beams, one could use the first position on the stock switch as low beams, and the second position as high beams, and wire it all up as shown here. I may put together a variation including the stock system of using the momentary switch on the stalk and the stock latching relay. This same system is used on many VWs, so the column switch and the relay are readily available cheaply.
Finally, this circuit will allow fog lights to be turned on any time the car is running, not just when the low beams are on. This is a commonly asked for "upgrade", and it's simple to do. To make the fogs work as stock, just replace the black power in wire at the fog switch with another yellow low-beams wire, powering the switch from the low-beams signal.
In the diagram, HLmSW is the "wiper" switch in the motor itself. Rm is the motor relay, which is found under that plastic cover near the motor in the stock setup. It's a standard 5-terminal relay, and the small numbers are the post numbers on the relay itself. A standard "square" 5-terminal relay could be substituted here, if your round relays are missing or dead.
I've not numbered the other relay terminals, because they're "standard", in that 85 is the switch power, 30 is power in, 87 is power out, and 86 is grounded. 87a isn't used (if you use 5-terminal relays), except on the low beam circuit, as part of the motor circuit.
I want to thank Clay Perrine for his headlight motor circuit diagram (in the Classic threads section), as it saved me the trouble of working out how the bloody thing worked by squinting at the wiring diagrams.
A couple of people have asked where to get wire, terminals, etc. Bulk wire is, in fact, the most costly part of doing a rewiring job. GOOD automotive grade wire has better insulation than the cheap stuff you get in many places, and the wire is always stranded, not solid core. Solid core wire flexes only so many times before it breaks. Stranded flexes thousands of times more, and will hold up under the high vibration environment of a car.
Waytek Wire sells auto grade wire, but only in fairly large quantities (100ft is the minimum for some sizes, 250ft for others). They only stock solid color wire, which is why I'm using that here. Tracer wire (wire with a second, thinner colored line on it) is available from them, but only as a special order, and only in pretty big quantities (may be 1000ft min, not sure). 250ft of wire in any color is enough to do more than one car in that one color (which would drive you mad the first time you had a wiring problem). Their prices aren't bad by the foot, but when you get 12 colors in two sizes at 250ft each, you're quickly looking at $300+.
British Wiring sells auto-grade wire in smaller quantities, but at a much higher per foot price. However, they DO stock tracer wire, so you can buy 10ft of (say) grey/black wire to repair a portion of your stock harness for a very reasonable price.
Both places also sell connectors, crimpers, terminals, etc. Waytek is a lot cheaper, again, but again have much higher minimum orders. For something really common, like female spade terminals (which you use a zillion of on a 914), their minimum will be used in a total rewire.
More on connectors and crimpers later...
Waytek Wire sells auto grade wire, but only in fairly large quantities (100ft is the minimum for some sizes, 250ft for others). They only stock solid color wire, which is why I'm using that here. Tracer wire (wire with a second, thinner colored line on it) is available from them, but only as a special order, and only in pretty big quantities (may be 1000ft min, not sure). 250ft of wire in any color is enough to do more than one car in that one color (which would drive you mad the first time you had a wiring problem). Their prices aren't bad by the foot, but when you get 12 colors in two sizes at 250ft each, you're quickly looking at $300+.
British Wiring sells auto-grade wire in smaller quantities, but at a much higher per foot price. However, they DO stock tracer wire, so you can buy 10ft of (say) grey/black wire to repair a portion of your stock harness for a very reasonable price.
Both places also sell connectors, crimpers, terminals, etc. Waytek is a lot cheaper, again, but again have much higher minimum orders. For something really common, like female spade terminals (which you use a zillion of on a 914), their minimum will be used in a total rewire.
More on connectors and crimpers later...
Sheesh, six months since I updated this...No progress on the car for months, then plenty in the last week or so, an hour here and there.
The car is now completely wired from the A-pillar back. Nothing in the front trunk (lights, wipers, horn) yet. The car runs, the charging system works, and the brake lights function, the dash is all wired up, so the car is drivable in the daytime, as long as it doesn't rain.
Some tricks picked up along the way:
Make sub-bundles of wire, grouping wires by major location. I have four wires leading from the rear trunk (taillights) to the dash, through the center tunnel. Another bundle goes from the engine bay, through the center tunnel, to the dash. Another bundle handles the dash itself (gauges/switches), and there will be a final bundle into the front trunk.
I roughly gauge the length needed, add a bit more, and cut the wires for each bundle. I then wrap some electrical tape around the wires every foot. To prevent chafing, I then slide each bundle down a length of protective high-temp tubing. Heatshrink works (you can buy long rolls of the stuff), or the expandable mesh-type wire covering (now popular with F1 teams, and used by Porsche OEM on recent cars). Note that heatshrink makes it hard to push through more than 3ft or so of wire. The internal friction just gets too great. Pulling the wire through is much easier, but you can't do that to start with. What I ended up doing here was cutting the tubing into 2 ft lengths, pushing the bundle through until it poked out the other end, then pulled the bundle through until it butted into the previous section. Then, you either tuck the end into the end of the previous section, or just use electrical tape.
To get bundles through the center tunnel, pull off the rubber elbow thing (it just pulls out of the upper tin and the rear firewall. Run the wire down through the engine shelf, then (from under the car), push it through the large hole in the firewall. There IS a hole that goes right into the tunnel (on the passenger's side of the tunnel, near the fuel lines), but you can't really see it unless the engine is out. You can feel it, though. Quite a few wires will fit through there, perhaps 25 18g wires, which is far more than required.
After you get all of the bundles through the center tunnel and sitting on the floor near the pedals, you can zip tie the bundles together.
I used a single 10g red wire from the + battery terminal, through the tunnel, to the junction under the dash near the fusebox. All power for the car (other than the alternator and the starter) will run through this wire. This is 6ft, roughly, and a 10g wire will handle 40A at 12v over that distance, which is more than enough, unless you have a serious stereo in the car.
After all of the wire bundles are run through the center tunnel, you can refit the rubber elbow by slitting along its length, wrapping it back around the bundles, then refitting it to the holes. This is far easier than trying to stuff the wires through the elbow intact.
The car is now completely wired from the A-pillar back. Nothing in the front trunk (lights, wipers, horn) yet. The car runs, the charging system works, and the brake lights function, the dash is all wired up, so the car is drivable in the daytime, as long as it doesn't rain.
Some tricks picked up along the way:
Make sub-bundles of wire, grouping wires by major location. I have four wires leading from the rear trunk (taillights) to the dash, through the center tunnel. Another bundle goes from the engine bay, through the center tunnel, to the dash. Another bundle handles the dash itself (gauges/switches), and there will be a final bundle into the front trunk.
I roughly gauge the length needed, add a bit more, and cut the wires for each bundle. I then wrap some electrical tape around the wires every foot. To prevent chafing, I then slide each bundle down a length of protective high-temp tubing. Heatshrink works (you can buy long rolls of the stuff), or the expandable mesh-type wire covering (now popular with F1 teams, and used by Porsche OEM on recent cars). Note that heatshrink makes it hard to push through more than 3ft or so of wire. The internal friction just gets too great. Pulling the wire through is much easier, but you can't do that to start with. What I ended up doing here was cutting the tubing into 2 ft lengths, pushing the bundle through until it poked out the other end, then pulled the bundle through until it butted into the previous section. Then, you either tuck the end into the end of the previous section, or just use electrical tape.
To get bundles through the center tunnel, pull off the rubber elbow thing (it just pulls out of the upper tin and the rear firewall. Run the wire down through the engine shelf, then (from under the car), push it through the large hole in the firewall. There IS a hole that goes right into the tunnel (on the passenger's side of the tunnel, near the fuel lines), but you can't really see it unless the engine is out. You can feel it, though. Quite a few wires will fit through there, perhaps 25 18g wires, which is far more than required.
After you get all of the bundles through the center tunnel and sitting on the floor near the pedals, you can zip tie the bundles together.
I used a single 10g red wire from the + battery terminal, through the tunnel, to the junction under the dash near the fusebox. All power for the car (other than the alternator and the starter) will run through this wire. This is 6ft, roughly, and a 10g wire will handle 40A at 12v over that distance, which is more than enough, unless you have a serious stereo in the car.
After all of the wire bundles are run through the center tunnel, you can refit the rubber elbow by slitting along its length, wrapping it back around the bundles, then refitting it to the holes. This is far easier than trying to stuff the wires through the elbow intact.
Why not use a "Painless Wiring kit" Summit / Jegs sell them. You can get 8 - 16 circurts for whatever you need. New Fuse box and color coded wires.
van914
van914
QUOTE(Van914 @ May 27 2006, 03:10 AM) 
Why not use a "Painless Wiring kit" Summit / Jegs sell them. You can get 8 - 16 circurts for whatever you need. New Fuse box and color coded wires.
van914
After market is OK for many applications and probably simpler. What James is doing is replicating a factory harness. Anyone doing a restoration (like me) will appreciate this thread a ton!
Actually, I'm NOT completely replicating a factory harness. The colors are not all the same, and I'm changing functions here and there to simplify the harness. My harness, in the end, will have 90% of the function of the factory harness. For example, I will not have parking lights, or hazard flashers (though those could be added easily enough). Where I hope this thread is useful is to show how to identify and repair sections of their own harness, and to de-mystify the whole process. Many people are terrified of electrics, and shouldn't be. Too many people have looked at the factory wiring diagram and just given up in frustration. By describing the harness in pieces, I hope it's clearer.
As for the Painless stuff, I find universal harnesses to be fairly unsatisfying. Either they're just a bundle of colored wire and a fusebox, or they're a "shaped" harness that can be laid out in the car as-is. The former doesn't cover the hard part at all, as obtaining the wire and a suitable fuse box is one order away, from several places (and it's easy to buy higher quality stuff than Painless sells). The latter means the shape of the harness has to match the car, roughly, and the Painless stuff pretty much assumes you're running a front-engined hot-rod, not a mid-engined car with the battery in the back and headlight motors in the front.
As for the Painless stuff, I find universal harnesses to be fairly unsatisfying. Either they're just a bundle of colored wire and a fusebox, or they're a "shaped" harness that can be laid out in the car as-is. The former doesn't cover the hard part at all, as obtaining the wire and a suitable fuse box is one order away, from several places (and it's easy to buy higher quality stuff than Painless sells). The latter means the shape of the harness has to match the car, roughly, and the Painless stuff pretty much assumes you're running a front-engined hot-rod, not a mid-engined car with the battery in the back and headlight motors in the front.
WOW! I had been trying ot do something like this for a while, but I could not spend the time to figure out Visio. Is that the program you are using?
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