Engine Electrical Wire Identification (FI)

[Jason0115]

I am trying to sort through and clear out wires that are not needed in my 75 bus. It was FI but converted to progressive carb. There are a lot of loose disconnected wires in the engine bay, and I don't know what wires go to what in some areas. In the video below, I count 1-10 the wires that I need help identifying and knowing if I can remove or not. Any help would be appreciated.

Also,
The engine turns over, fuel pump and starter work just fine. Coil has 12v at the two terminals. But the spark plugs get no spark. Also, the coil wire doesn't produce a spark. What could be wrong here? I was going to replace battery cable and ground wire, points, distributer cap, ignition rotor, and the coil for a general refresh and to hopefully fix this problem, do you think this would work?

My video:


Link

[Wildthings]

Your ignition points need to open and close as the engine is cranked. They also need to be clean enough to pass electricity. If you are running Bosch points, they are poorly built these days and the plastic rubbing block is notorious for breaking off leaving you stranded, best to buy Echlin or Beru. You condenser can go bad as well, causing a week spark and burning up your points, again its best to use something besides newer Bosch parts.

The voltage on the #1 (negative) terminal on the coil should bounce between 0 and 11+/- volts when you crank the engine over. When the engine isn't running and you have the ignition turned on, the voltage on the #1 terminal may be either 12v or 0v depending on if the engine is stopped with the points open or closed. Don't leave your key on for more than a few minutes if the engine isn't running.

I would be careful about cutting up and removing any factory wiring, you may well want to go back to fuel injection someday and it would be nice if it were plug and play.

[mikewire]

Well...a lot to unpack and sort through there. Lots of PO wiring hacks, some of those are just leftovers from the stock FI.

I/we can go through and help ID by #.

Let me watch again and I'll do my best, I'll edit this post.

#1: Hard to tell, could be a PO add. I don't think it's OEM wiring, but maybe it's misrouted fuel sender wiring? Can you trace it up?

#2: Most likely those are side marker lights on the drivers side. All that wiring should be tucked up to the top of the engine bay.

#2B: No idea, you'll want to trace from the engine bay forward, maybe added trailer lights?

#3: Fuel pump plug from the double relay (missing) left over from the stock FI system.

#4: Black is the fused reverse lights, from #15 on the coil, +12V. Orange, no idea, trace it forward (I'm guessing to the fuel pump, bad bad bad!). Black/red, trace it forward (starter?)

#5: Not a wire, it's a vent tube from the fuel tank, not in the proper place. Pull it until you figure out where it needs to go.

#6: Vac port on the carb. Leave it capped for now.

#7: Fused 12v to the heating booster fan. Not a heating unit, just a fan to help boost the air to the front of the cab from the back of the Bus.

#8: Voltage regulator. You'll need it, it assists in the regulating charging voltage from your alternator and battery.

#9: I think you're correct...probably side marker lights for the passengers side.

#9b/c?: diagnostics port for an old diag machine dealers had back in the day. Leave it be, but that wire coming out of it needs to be traced back, to make sure it's not a fire hazard.

#10: Yes, taillights/stoplights.

#11 - bonus question: That is the support for the stock FI air filter box.


Quite the Pandora's box there! I'd suggest you start looking at the wiring diagram and the puzzle peices will start to fit together. There's a lot of stuff there to un-f*ck and make good again! Definitely something you can tackle with some hearty determination and common sense.




...
_________________
-Mike

@countdowngarage
@bigskyeuro

1972 VW Kombi 9 Passenger Deluxe w/ 2.0L F.I. VWAC swap
1965 VW Beetle Deluxe Bahama Blue

[Daverham]

OK, since I just got some help, it's time to give back before I disappear again. I can knock off a couple of the easy ones.

For this one (above) using my own numbers that correspond to my pics:
#1 is the connector from the main vehicle wiring harness to the FI double relay (which is gone). See link below for what that connects to on the other end. You probably want to just leave that there, unless there was anything related to the coil and/or starter that passed through that relay. And that might be the case. See diagram. Either way, don't cut it off.

Relay Diagrams: https://ratwell.com/technical/DoubleRelay.html

#2 Is the resistor block for the FI. You can remove that, but you probably want to make sure that ground wire is connected - unless it ONLY serves the FI. I'm not sure about that. Can't hurt to connect a brown wire to ground though.

#3 This plug would have connected the resistors to the FI harness, so you don't need that. Save it / sell it for somebody who needs one.


Next pic.

A. The holder in question used to hold up your air filter and air flow meter. So you don't need anything there for carbs.

B. This is where the "brain" for the FI used to go.


This is what the FI harness looks like. It's a self-contained little harness that you can do without at this point. Maybe it's already gone, I don't know. But the odds are good that if you find/recognize any of these wires/connectors, you can yard out everything that they are connected to because they were all part of the FI system.

[Wildthings]

#9 might well have been a wire connecting a second battery to the starter battery.

To power your coil and the choke heater on the carb, you need switched power from the ignition switch. it would have entered the engine compartment on the right side and may be bundled with the wires going to the heater booster fan. Yes you need the voltage regulator hooked up if you want your battery to charge.