'78 Westy- FI engine install re-wire.. What goes where?

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Jivermo
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'78 Westy- FI engine install re-wire.. What goes where?

Post by Jivermo » Fri Jun 19, 2015 5:29 am

I'm close to getting my Adrian rebuild back into my bus-this weekend for certain. Now I'm looking at the spaghetti land of wires and harnesses, and wondering what goes where. Surely there is a forum somewhere that details this, that is easier than straining with the Bentley wiring diagrams-oh, my Lord in Heaven!
Anyone got any good tips for me? I want to break in this engine, and see what surprises, if any, await.

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THall
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Re: '78 Westy- FI engine install re-wire.. What goes where?

Post by THall » Fri Jun 19, 2015 10:10 am

Jivermo wrote:I'm close to getting my Adrian rebuild back into my bus-this weekend for certain. Now I'm looking at the spaghetti land of wires and harnesses, and wondering what goes where. Surely there is a forum somewhere that details this, that is easier than straining with the Bentley wiring diagrams-oh, my Lord in Heaven!
Anyone got any good tips for me? I want to break in this engine, and see what surprises, if any, await.
If you could post pictures of the wires in question, I'm sure we could help you out. Is it just engine bay wiring and FI harness? I recently did the install on my '78 FI and could post some pictures as well if that would help?
'78 Westy 2.0 FI

Jivermo
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Re: '78 Westy- FI engine install re-wire.. What goes where?

Post by Jivermo » Fri Jun 19, 2015 10:57 am

Thanks. I'll do that when I get there.

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SlowLane
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Re: '78 Westy- FI engine install re-wire.. What goes where?

Post by SlowLane » Fri Jun 19, 2015 12:41 pm

As intimidating as it may first appear, the FI harness is nearly self-explanatory. Once laid out, the various connectors pretty much fall pretty close to where they need to be plugged in, and for the most part, they can only plug into one of the available sockets. The major exception to this is at the center of the engine where you have three physically identical connectors only differentiated by colour. These are for the Thermo-Time Switch (rusty-red), the Cold Start Valve (pale blue), and the Auxiliary Air Regulator (basic black).

To get oriented, start by laying out the harness loosely on top of the engine with the ECU plug near the ECU, then route the rest of the harness loosely around the front of the engine (flywheel is at front, per St. Muir). The connectors should fall naturally near where they need to go.

The injectors all fire simultaneously, so you don't need to worry about mixing up injector plugs 1&2 or 3&4. The AFM connector, double relay and resistor block connectors are all unique, so there should be no mix-up there. The TSII connector is the only one of its kind at that end of the harness. Ditto for the WOT switch connectors (if you have a WOT switch). The ignition input signal wire is off on its own pretty much separate from the main harness, so it goes to the condenser side of the coil.

The biggest hassle seems to be getting it all tucked away neatly, and as you've noted, the pesky ground block under the plenum.

Just tackle it methodically and it will come together.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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Amskeptic
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Re: '78 Westy- FI engine install re-wire.. What goes where?

Post by Amskeptic » Sat Jun 20, 2015 9:02 pm

Jivermo wrote:I'm close to getting my Adrian rebuild back into my bus-this weekend for certain. Now I'm looking at the spaghetti land of wires and harnesses, and wondering what goes where. Surely there is a forum somewhere that details this, that is easier than straining with the Bentley wiring diagrams-oh, my Lord in Heaven!
Anyone got any good tips for me? I want to break in this engine, and see what surprises, if any, await.
The harness path was changed in 1978. Lay out and clip the spark plug wires first. They go under all of it.

ECU trunk to first branch runs behind the right fuel rail. First branch goes between intake runners 1 and 2. AFM branch goes up at same area. Harness takes a difficult path ahead of the breather and along the AAR. You need to figure out which way to allow the AAR branch and the CSV branch to run, below or above the main harness. Main harness then runs diagonally under #4 runner. I elected to send injector branches between the runners for #3 and #4 injectors. You decide the easiest straightest least wrinkled or twisted path to the series resistors and double relay. NO CHAFING. Think creatively and neatly. Be glad that you do not have a 1976 harness. Yuck on their path up under the throttle body. Use a hair dryer to soften harness and untwist memory of possible old wrong layout.

Image

Image
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

Jivermo
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Re: '78 Westy- FI engine install re-wire.. What goes where?

Post by Jivermo » Mon Jun 22, 2015 1:04 pm

Image

You'll notice the two harnesses above, that were intertwined for my 70 amp alternator. I believe that the black wrapped one was made because the original harness had a defect in the plug section of the piece. It was kept, however, for the use of the wiring ending in the ring connectors. I have the one end of the black wrapped section plugged into the alternator.
1) where does the other plug go, with the small blue wire also?
2) where do the ends of both ends of the ring connector wire go? I see a large post on the alternator, does one end go there? I can see no other option for that end, but I don't want to fry something by hooking it up incorrectly. Where does the other ring connect?
I have looked at the Bentley wiring diagram, but that makes as much sense to me as Hedge funds.
Man, one thing after another with this.

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Amskeptic
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Re: '78 Westy- FI engine install re-wire.. What goes where?

Post by Amskeptic » Tue Jun 23, 2015 10:30 am

Jivermo wrote: 1) where does blue wire ?
2) where do the ends of both ends of the ring connector wire go?
Blue plugs into blue wire leading into the main harness just below the regulator that delivers to the warning lamp.

Red ring connectors connect alternator B+ to starter solenoid post where battery cable is also. Put it directly next to the battery cable end on the starter solenoid post.
ColinTOMONTANAATONCE
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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