Big Blue's Transformation

[ArdWrknTrk]

Ok, time for a picture. I was ready to say this piece of the wiring is done, but as it turns out it isn't - quite. As it turns out, the shielding isn't grounded, so I have to do that, which will be easy. And I need some larger convolute to cover the run from the ECU to the PDB, and what I saw online has a one week delivery date, which isn't to my liking. So I'll be doing some more looking.

As for what is left to do:

• Install the system and mate up all the connectors, install the grounds, and install the OBD-II connector under the dash

• Run wires from the Emissions and Low Range lights to a connector to match the one coming from the ECU

• Build the cable that will go from C110 to the O2 sensors

• Install the diode on the A/C compressor connection and connect the wire that goes back to the ECU to that

• Make a short #2 cable to go from the PDB to the Cole Hersee battery parallel relay

After that it is down to things like set the ignition timing per Bill's instructions, test fuel pressure, and see if it'll run.

But you are tantalizingly close!

Which calls for the ubiquitous..... Progress is good!.

Awesome job on your extended wiring loom.

And getting that massive document scanned and posted real progress too.

I hope this brings Big Blue that much closer to your vision for him.

 

[Gary Lewis]

But you are tantalizingly close!

Which calls for the ubiquitous..... Progress is good!.

Awesome job on your extended wiring loom.

And getting that massive document scanned and posted real progress too.

I hope this brings Big Blue that much closer to your vision for him.

Thanks, Jim. It is certainly bringing Big Blue a lot closer to my vision for him. That vision includes a system that is fairly modern and can be maintained by the "mechanics" whose first line of defense is a code scanner.

But there's also this yearning to see how "efficient" I can make a 460. Maybe actually pass two gas stations in a single bound?

Anyway, thanks!

[ArdWrknTrk]

Thanks, Jim. It is certainly bringing Big Blue a lot closer to my vision for him. That vision includes a system that is fairly modern and can be maintained by the "mechanics" whose first line of defense is a code scanner.

But there's also this yearning to see how "efficient" I can make a 460. Maybe actually pass two gas stations in a single bound?

Anyway, thanks!

I put $172 worth of gas in my truck the other day!

Still not an all time record, but definitely a stark reminder of what a pig she is.

[Gary Lewis]

Thanks, Jim. It is certainly bringing Big Blue a lot closer to my vision for him. That vision includes a system that is fairly modern and can be maintained by the "mechanics" whose first line of defense is a code scanner.

But there's also this yearning to see how "efficient" I can make a 460. Maybe actually pass two gas stations in a single bound?

Anyway, thanks!

Note that I used quotes around "efficient" since it was used in the same sentence as "460". I don't think that I'm going to break any records, but I do hope for a bit of an improvement. Those two 19 gallon tanks seem to empty relatively quickly, and this thing is going to Arkansas on an overlanding with my son in October, so any improvement will be appreciated.

And I finally found the stuff I was looking for, or close enough, that will get here in a reasonable time. Ordered 25ft – 1 inch Split Wire Loom and this Heat Shroud Aluminized Sleeving for Ultimate Heat Shield Protection Barrier with Hook and Loop Closure - 1" x 36".

The split loom will let me cover the run from the PDB to the ECU, and while 1" is slightly too big as it measures more like 7/8", it'll give me a bit of extra room. It is rated at 257F, which I think will be enough as the run stays pretty well away from the exhaust.

However, Ford used some kind of aluminized insulation for the run from C101 at the PDB to the engine since it runs right above the exhaust. So I'll use the "heat shroud" to cover the convolute in that run, just like Ford did.

[Gary Lewis]

Note that I used quotes around "efficient" since it was used in the same sentence as "460". I don't think that I'm going to break any records, but I do hope for a bit of an improvement. Those two 19 gallon tanks seem to empty relatively quickly, and this thing is going to Arkansas on an overlanding with my son in October, so any improvement will be appreciated.

And I finally found the stuff I was looking for, or close enough, that will get here in a reasonable time. Ordered 25ft – 1 inch Split Wire Loom and this Heat Shroud Aluminized Sleeving for Ultimate Heat Shield Protection Barrier with Hook and Loop Closure - 1" x 36".

The split loom will let me cover the run from the PDB to the ECU, and while 1" is slightly too big as it measures more like 7/8", it'll give me a bit of extra room. It is rated at 257F, which I think will be enough as the run stays pretty well away from the exhaust.

However, Ford used some kind of aluminized insulation for the run from C101 at the PDB to the engine since it runs right above the exhaust. So I'll use the "heat shroud" to cover the convolute in that run, just like Ford did.

Well, I was wrong when I thought I was wrong.

I got to thinking about the lack of grounding on the shields for the ignition & misfire circuits. I had checked for continuity at all the grounds I could think of in the system, but something was nagging me.

So I pulled out the Ignition System schematic from the 1996 EVTM and discovered that the shields on both circuits are grounded at the distributor.

But the engine harness, which includes the wiring to the dizzy, is already installed so I couldn't test at that connector. However, the ground runs through C101, so I was able to test there and discovered that both shields are grounded there.

Now some of you may be thinking I should just go ahead and ground the shields again at the ECU end to ensure they are well grounded. However, that is sure to cause "ground loops" since the voltage at that ground is almost sure to be different from the voltage at the distributor. That means there will be a current through the shield, and that is called a "ground loop" - which is a no-no in low voltage systems like the EFI system.

In fact, here's part of what Wikipedia says about ground loops:

In an electrical system, a ground loop or earth loop occurs when two points of a circuit are intended to have the same ground reference potential but instead have a different potential between them...

Ground loops are a major cause of noise, hum, and interference in audio, video, and computer systems. Wiring practices that protect against ground loops include ensuring that all vulnerable signal circuits are referenced to one point as ground...

So I'm glad that I checked.

[grumpin]

Well, I was wrong when I thought I was wrong.

I got to thinking about the lack of grounding on the shields for the ignition & misfire circuits. I had checked for continuity at all the grounds I could think of in the system, but something was nagging me.

So I pulled out the Ignition System schematic from the 1996 EVTM and discovered that the shields on both circuits are grounded at the distributor.

But the engine harness, which includes the wiring to the dizzy, is already installed so I couldn't test at that connector. However, the ground runs through C101, so I was able to test there and discovered that both shields are grounded there.

Now some of you may be thinking I should just go ahead and ground the shields again at the ECU end to ensure they are well grounded. However, that is sure to cause "ground loops" since the voltage at that ground is almost sure to be different from the voltage at the distributor. That means there will be a current through the shield, and that is called a "ground loop" - which is a no-no in low voltage systems like the EFI system.

In fact, here's part of what Wikipedia says about ground loops:

In an electrical system, a ground loop or earth loop occurs when two points of a circuit are intended to have the same ground reference potential but instead have a different potential between them...

Ground loops are a major cause of noise, hum, and interference in audio, video, and computer systems. Wiring practices that protect against ground loops include ensuring that all vulnerable signal circuits are referenced to one point as ground...

So I'm glad that I checked.

That’s great! Good thing you found it now!

[Gary Lewis]

That’s great! Good thing you found it now!

Yes, Dane, I'm really glad I found it.

But I also realized I had something else that needed doing - the horn wire. In the pic above there's a coil of yellow wire that was from the '96 harness and ran from the horn relay to the horns. Apparently they were in the right front instead of the left front as there was a lot of wire so needed to be shortened. And, it needed to have a connector between the PDB and the wire to allow me to remove the PDB and associated wiring.

So I fished the wiring to the bull horn out of the front of the truck and disconnected the original wire. I connected the '96 wire to that and at about 24" back put a 1-pin connector pair in. Then I covered the horn end of that with convolute and then snaked it back along the fender liner, leaving it in a handy place for when I put the PDB et al in.

And I also put the battery charger on the starting battery just so it'll be "hot".

[Gary Lewis]

Yes, Dane, I'm really glad I found it.

But I also realized I had something else that needed doing - the horn wire. In the pic above there's a coil of yellow wire that was from the '96 harness and ran from the horn relay to the horns. Apparently they were in the right front instead of the left front as there was a lot of wire so needed to be shortened. And, it needed to have a connector between the PDB and the wire to allow me to remove the PDB and associated wiring.

So I fished the wiring to the bull horn out of the front of the truck and disconnected the original wire. I connected the '96 wire to that and at about 24" back put a 1-pin connector pair in. Then I covered the horn end of that with convolute and then snaked it back along the fender liner, leaving it in a handy place for when I put the PDB et al in.

And I also put the battery charger on the starting battery just so it'll be "hot".

As of today I believe everything is ready for the installation of the PDB & ECU wiring.

But, let's walk through what I did today step by step. This morning I installed diodes, plural, on the A/C compressor circuit and connected the sense wire from the ECU to it.

The first diode is on the connector to the compressor. I pulled the pins, twisted the legs of the diode around the pins, soldered them, and put them back in - after making the holes in the connector a bit bigger as they weren't quite big enough with the addition of the diode's legs. But I like the diode as close to the source of the EMF as possible, so this should be that.

Anyway, here's what that looks like. That's a 10A diode, which should be more than adequate for a 4A clutch.

Then, realizing that I'd gotten a total of 10 diodes in I added one to the wiring in the engine harness where the DG/O wire is that goes back to the ECU from the A/C clutch. This is just a safety, and grounds to the ground in that harness, Ckt #57. And that connector let's me pull either harness off w/o messing with the other one.

About then Amazon delivered both the 1" convolute awa the 1" x 36" heat protection for cabling. I measured and the run between C101 and the engine could use an 18" piece, so I cut it in half and put one half on that run. I'll use the other half to protect the run between the ECU and PDB where it is above the exhaust at the firewall.

Anyway, here's a shot with the heat shield on the run to the engine. Seems to fit right in with all the other shiny stuff.

Last, I tapped into the MIL and 4 Low light circuits and ran them to a connector near the ECU's new home. I know about the MIL light, but it'll be interesting to see what happens when the transfer case is put in 4 Low.

Oh yes, I tested them by adding battery power to Fuse 8, which powers both circuits, and then grounding the pins in the connector. They worked!

And speaking of "adding battery power" to a fuse, I should explain. I have a little battery that is really for setting trailer brakes in a disconnect condition. But I use it to test circuits when I don't have the main battery connected as it is quite portable. However, I needed a way to tap into the fuse box one circuit at a time and wound up adding wires to a blown fuse. So I plug it into the fuse box, connect the wire that goes to the downstream circuit to the battery, and do my testing. In this case it let me see that the lights work as they should w/o worrying about other circuits that might not be ready.

[85lebaront2]

As of today I believe everything is ready for the installation of the PDB & ECU wiring.

But, let's walk through what I did today step by step. This morning I installed diodes, plural, on the A/C compressor circuit and connected the sense wire from the ECU to it.

The first diode is on the connector to the compressor. I pulled the pins, twisted the legs of the diode around the pins, soldered them, and put them back in - after making the holes in the connector a bit bigger as they weren't quite big enough with the addition of the diode's legs. But I like the diode as close to the source of the EMF as possible, so this should be that.

Anyway, here's what that looks like. That's a 10A diode, which should be more than adequate for a 4A clutch.

Then, realizing that I'd gotten a total of 10 diodes in I added one to the wiring in the engine harness where the DG/O wire is that goes back to the ECU from the A/C clutch. This is just a safety, and grounds to the ground in that harness, Ckt #57. And that connector let's me pull either harness off w/o messing with the other one.

About then Amazon delivered both the 1" convolute awa the 1" x 36" heat protection for cabling. I measured and the run between C101 and the engine could use an 18" piece, so I cut it in half and put one half on that run. I'll use the other half to protect the run between the ECU and PDB where it is above the exhaust at the firewall.

Anyway, here's a shot with the heat shield on the run to the engine. Seems to fit right in with all the other shiny stuff.

Last, I tapped into the MIL and 4 Low light circuits and ran them to a connector near the ECU's new home. I know about the MIL light, but it'll be interesting to see what happens when the transfer case is put in 4 Low.

Oh yes, I tested them by adding battery power to Fuse 8, which powers both circuits, and then grounding the pins in the connector. They worked!

And speaking of "adding battery power" to a fuse, I should explain. I have a little battery that is really for setting trailer brakes in a disconnect condition. But I use it to test circuits when I don't have the main battery connected as it is quite portable. However, I needed a way to tap into the fuse box one circuit at a time and wound up adding wires to a blown fuse. So I plug it into the fuse box, connect the wire that goes to the downstream circuit to the battery, and do my testing. In this case it let me see that the lights work as they should w/o worrying about other circuits that might not be ready.

I am pretty sure my AC clutch wiring had the diode in it, but it came from the 1990 truck.

I just noticed how far forward the Hydroboost puts your master cylinder, I imagine plug changes will be fun.

Plug wires, since you have headers, you might want to try to keep the wires closer to the valve covers to keep them from getting too hot.

[Gary Lewis]

I am pretty sure my AC clutch wiring had the diode in it, but it came from the 1990 truck.

I just noticed how far forward the Hydroboost puts your master cylinder, I imagine plug changes will be fun.

Plug wires, since you have headers, you might want to try to keep the wires closer to the valve covers to keep them from getting too hot.

Yes, the later ones apparently did have the diode. The '96 EVTM shows it, for sure. Which is why I could see that I needed it. I traced that DG/O wire right to it, looked at the '85 harness and realized it was AWOL. So I added two.

As for changing plugs, don't forget I have the topsider creeper, which will make it a whole lot easier.

But I'll see what I can do on the plug wires, thanks. But don't forget that I have several thousand miles on the engine already.