The Mule rides again (sort of) - pics.

[The Dark Side of Will]

Last weekend I got a couple of small things done, as well as a bunch of lines on the wire list.

Added a T to the oil pressure elbow in order to make a fitting tree. The oil pressure transducer should stick out over top of the cradle crossmember, while the switch/sender should hide behind it. I'll have to turn the wiring tight so that it doesn't hang down below the bottom of the pan.



I clocked the alternator rear case in order to bring the stud close to the block and bring the rear mounting boss close to the existing hole in the bracket. The bracket doesn't fit because it was designed for a CS144 alternator and this is a CS130.



A longer shot down the side of the block. Yes, I'll have to do a lot more modification to the bracket in order to use the stud. I just drilled the hole quick and dirty in order to get everything into relative position.



Accessory drive with belt. I hope it clears the battery tray.



Closeup of the bracket... All I really did was move the tensioner and the idler... and the top alternator mount a little bit



And the junction block + mount bracket, before I drilled the mounting holes

[The Dark Side of Will]

Been looking for CS130 info in order to set up the wiring correctly. There's a lot of minimalist stuff for people who are scared of wires.

I finally found this:
https://alternatorparts.com/cs130-sbpage1.html

Page 2 actually has the terminal definitions... only place I've ever seen them.

Maybe I should hook up the P terminal to a frequency input on the ECM so I can log alternator RPM next to engine RPM and evaluate the performance of my accessory drive...

[The Dark Side of Will]

Since I have the accessory drive figured out, I went ahead and installed the crank damper.
I have both a GM bolt and an ARP 251-2501 to choose from. The thread is M14x1.5 and ARP happened to have a bolt for a Ford Duratec that should work. The ARP bolt comes with a hardened washer, but the chamfer on the edge of the washer and the lead in chamfer around the bore in the crank damper are the same size, so the washer contacts the damper on the 45 degree face. That's probably not a great thing to do.

The GM bolt has a larger washer (slightly convex, so it may have some "belleville spring" effect. The ARP washer is loose, but the GM washer is captive. I'd have to chuck the GM bolt in a lathe and turn the threads down a little bit to remove the washer.
I need to check the GM torque procedure... ARP's instructions say 140 ftlbs, but the generic instructions have numbers from 184 to 205 ftlbs for a 14mm bolt. Since the clamp load of the damper on the oil pump drive sleeve is the ONLY interface that provides oil pump drive torque, I want to overkill it where I can.

https://www.summitracing.com/parts/arp-251-2501

I picked up crimp lugs for the 4ga starter cable and 3/8" stud on the junction block I showed above. I'll get the cable cut and stripped this week, then mark the orientation for the lug next weekend, then get it crimped next week. ALLTRBO works in electrical & harness and has the tooling. Stuff he built is orbiting the Moon, so he can do fine for The Mule.

I also did a bunch of reading on CS130 alternator terminals in order to get my alternator wiring right. I posted the link to the page above. V6 Fieros have older type SI alternators, while Iron Duck Fieros (at least in '87) have the then new CS alternator. The Fiero CS alts have the SILP terminal configuration, while the 2006 Corvette (and many other apps) have the SFLP terminal configuration. The 2006 Corvette *I think* has the CS130D alternator, since the original CS130 stopped in 1996.

P
Pulse?
Connected to the stator, and may be connected externally to a tachometer or other device

L
Lamp?
Alternator “Turn on” voltage. This must run through an indicator lamp or other resistance.
Fieros use HIRBTS, but could work with a HIR source as well. Fed through C500 B3

F / I
Field?
Internal? Indicator?
Connected internally to field positive, and may be used as a fault indicator.
Corvette ECM monitors regulator duty cycle via the F terminal
1987 Fiero 4 cylinder connects I terminal to HIR +12V via C500 B1

S
Sense?
May be connected externally to a voltage, such as battery voltage, to sense the voltage to be controlled.
May be connected directly to the output stud to simplify installation; Fiero installation does this
May be connected directly to fuse block in order to compensate for resistive losses in the alternator cable; Corvette installation does this

1987 Fiero (4 cylinder):
S Wired directly from output stud
I From Fan E fuse (HIR) via C500 B1
L From Gages fuse (HIRBTS) through charge indicator via C500 B3 to turn on alternator
P Not used

2006 Corvette
S From Horn/Alt fuse (Hot at all Times)
F To ECM to monitor Field duty cycle
L From ECM to turn on alternator
P Not used

The Mule:
S Wired directly from output stud? From engine junction block? From body junction block?
F To ECM to monitor Field duty cycle
L From Gages fuse (HIRBTS) via C500 B3; maintains indicator lamp functionality
P Not used

I'll pick a place from which I want to sense the voltage to which the alternator regulates. I'll connect the F terminal to the ECM as in the Corvette application. If I wire the L terminal like the Corvette, the ECM will turn the alternator on and off, which is cool, but I would lose charge indicator functionality. I can wire the L terminal to the Fiero charge indicator light in the dash, then the alternator will turn on in RBT&S and I'll still have a functioning charge indicator. I'm not sure if the Corvette ECM will have heartburn over this arrangement or not.

Also, Trinten on Old Europe asked for the resistances of my Magnecor wires:

2: 3.64k
4: 3.67k
6: 3.66k
8: 3.56k

1: 1.65k
3: 2.13k
5: 2.13k
7: 1.65k

Easy to see there are 3 different lengths.

[The Dark Side of Will]

To Dos and stuff I haven't written down yet:

=>Design spacer for tensioner pulley to compensate for thickness of adapter bracket
=>Obtain larger diameter tensioner pulley that does not already have one shoulder removed; should be larger diameter to slow it down when the engine's turning 8500 RPM.

=>Make the build/buy decision for coil harnesses. Build: I get exactly what I want vs. I have to build it. Buy: I don't have to make it and it'll work vs. I don't get exactly what I want, which impacts main harness packaging.

=>Measure crank damper and compare to book diameter to determine effective diameter for calculating accessory drive ratio.

Injector power comes from the TBI INJ1 and TBI INJ2 fuses on the Fiero. GM powers 3 injectors with each of these 5A fuses, and I ran 4 injectors on each of them with the Shelby system. FieroGuru is running both one bank of coils and one bank of injectors on EACH of his injector fuses. The 2006 Corvette and DTS run one bank of injectors on each of their injector fuses, but those fuses are 15A and 20A, with smaller injector wiring than the Fiero has. Wired this way, whenever injector duty cycle is over 12.5%, there are 2 injectors on at the same time in each fuse and when DC is over 25%, there are three on at the same time. The 1995 Caddy splits the injectors according to the firing order, with 1,4,6,7 on one fuse and 2,3,5,8 on the other. This reduces the amount of time that more than two injectors are on such that at DC's less than 25%, only one injector is firing at a time on each fuse. Three injectors at a time doesn't happen until >50% DC. This seems like a better way to utilize 5A fuses. Since my manifold harness is already wired this way and I'm avoiding molesting it, I'll stick with this configuration.

I will power my coils from the same circuit as GM powered the Fiero ignition. That's circuit 3 (yes, circuit number 3) in the Fiero which is a 12ga wire directly from the ignition switch to C500-E3. It is *UN*fused, so... don't screw up. GM did not fuse it at all for the Iron Duck DIS, and used a fusible link for the 2.hate ignition coil. I need to check the harness to see if I used an inline fuse with the Shelby system on the Northstar DIS. I never had any problems with using this circuit. It seems to have plenty of capacity.

I will power O2 sensor heaters from the FAN E fuse via C500-B1. The heaters are controlled by the ECM, and should not be needed at the same time as the cooling fan, so this seems pretty safe.

There's a brake pedal switch input to the ECM... not necessary, but I want it. I need to figure out the elegant way to make that happen.

Also need to pay attention to the DBW pedal, but can probably put that off until I get the powertrain installed

Both the A/C request and cruise control will have to happen via the GMLan CANBus. I'll wire them both up to the C203 interface, with the expectation that in the future I'll incorporate a bus gateway of some type on the ECM side of that interface.

[The Dark Side of Will]

Ryan/Darth/Sinister says that I need to implement the PWRTRN relay and all the circuits derived from it in order for the ECM's post-shutdown diagnostics, most importantly of the ETC, to proceed correctly. I was starting to think I could spread all the new loads out across the Fiero electrical system and plug/chug without adding a new electrical center. Oh well...

Also, GM runs the injectors and coils on the same fuse for each bank. Funky. Also, FieroGuru said he went from 5A fuses to 10A for the TBI INJx fuses in the Fiero. Should be safe given the wire sizes.

[ericjon262]

Funny, I read your last post and thought "sounds easier to add the load center you linked to"...

[The Dark Side of Will]

Funny, I read your last post and thought "sounds easier to add the load center you linked to"...

Relays have weight... The Fiero system could handle it with a little design effort. There isn't much added demand of the 58x system vs. the Shelby system and the Shelby system ran fine with thoughtful electrical integration.

[The Dark Side of Will]

Of course if I can actually get some data on the electrical center... I can probably move A/C comp & fuel pump relays into it. Doing that would get it up to 3 relays and 5 fuses. That's worth an electrical center, I think. Moving the A/C power relay to the engine compartment would probably be more trouble than it's worth and not save any weight.

[ericjon262]

Of course if I can actually get some data on the electrical center... I can probably move A/C comp & fuel pump relays into it. Doing that would get it up to 3 relays and 5 fuses. That's worth an electrical center, I think. Moving the A/C power relay to the engine compartment would probably be more trouble than it's worth and not save any weight.

On my car, I used a relay for the ignition coil power, similar to a fuel pump "hotwire" kit. In doing this, less current runs through the IGN switch, which should help prolong the life of the switch. in fact, almost all of my engine related IGN+ loads are off of a relay now.

[The Dark Side of Will]

I had been thinking about that from the perspective of weight reduction... but to lose any weight, I'd have to rewire the car with 22ga instead of 12ga... which is a lot of work.

If I already have the electrical center, I guess I could add ignition and maybe even crank/run relays there and, as you said, reduce the current through a 35 year old ignition switch (Actually, I replaced it, so it's <10 years old)

[ericjon262]

I had been thinking about that from the perspective of weight reduction... but to lose any weight, I'd have to rewire the car with 22ga instead of 12ga... which is a lot of work.

If I already have the electrical center, I guess I could add ignition and maybe even crank/run relays there and, as you said, reduce the current through a 35 year old ignition switch (Actually, I replaced it, so it's <10 years old)

I'm all about stripping weight from a vehicle, but I don't think the juice is worth the squeeze for what you're describing, I get it hat ounces add up, but so does having a good voltage supply to your ignition/fuel pump/ECU ect.

[The Dark Side of Will]

I had been thinking about that from the perspective of weight reduction... but to lose any weight, I'd have to rewire the car with 22ga instead of 12ga... which is a lot of work.

If I already have the electrical center, I guess I could add ignition and maybe even crank/run relays there and, as you said, reduce the current through a 35 year old ignition switch (Actually, I replaced it, so it's <10 years old)

I'm all about stripping weight from a vehicle, but I don't think the juice is worth the squeeze for what you're describing, I get it hat ounces add up, but so does having a good voltage supply to your ignition/fuel pump/ECU ect.

I was referring to the fact that in older cars, GM will run 20 feet of 12ga wire through switches to connect components that are 2 feet apart. This is worse in the Fiero because the battery, fuse block, ignition switch and major loads are much further from the battery in the Fiero than in other contemporary platforms. Redesign the harness to use single power wires to different sections of the car with distributed fusing and relays operated by 22 ga wire, and there's weight to be saved, but it's a lot of work.

[ericjon262]

you could lose more weight by not having redundant sensors and transmitting coolant temp, oil pressure, RPM, VSS ect from the ECM to a dashboard over a CAN or Serial link.

also, with the convenience center, you can have an IGN+ from the switch run a relay, which then powers all of your engine related IGN + loads, and the relay triggered off of one smaller gauge wire instead of multiple wires running to and from the dash, offsetting some of the weight gained, while simplifying the installation.

[The Dark Side of Will]

I guess the implication that I'm actually not going to tear the entire car apart to rewire the entire system to save 10-20 lbs was not sufficiently obvious.

Yes, I totally get the superiority of modern electrical design and understand that GM's design--AT THE TIME--was the cheapest way they could do it, not the best or lightest.

But since it's a tough concept... adding things--without also taking other things away--does in fact result in a weight gain

[The Dark Side of Will]

*THIS* looks like the Delphi electrical center that EFI Connection didn't want to give me the PN for...

https://www.customconnectorkits.com/12146281/

Guess I need to give these guys a call about the BOM for actually putting one of these together.

EDIT:

I didn't know the relay mounting clips were available on their own:

https://www.customconnectorkits.com/12146281/

Of course that's still not the Fiero's OE "2-3 relays on one hanger" gizmo, but time marches on.

[eHoward]

For what it’s worth I had thought you were about to rip all the wiring out of the car

If you can drop 20lb in wiring, I am sure there’s a job for you in F1.

I guess the implication that I'm actually not going to tear the entire car apart to rewire the entire system to save 10-20 lbs was not sufficiently obvious.

Yes, I totally get the superiority of modern electrical design and understand that GM's design--AT THE TIME--was the cheapest way they could do it, not the best or lightest.

But since it's a tough concept... adding things--without also taking other things away--does in fact result in a weight gain

[The Dark Side of Will]

For what it’s worth I had thought you were about to rip all the wiring out of the car

If you can drop 20lb in wiring, I am sure there’s a job for you in F1.

I did have to think hard about how much work it would actually be...

I'm confident I can drop a bunch of weight vs. a 1980's GM electrical system, and especially vs. the Fiero's electrical system. The crank wire by itself is 20+ feet of 12 gauge wire (~2lbs) and multiple high current switches (ignition, clutch/shifter) that could be 2 feet of 12ga (~0.2 lbs) and a relay with 20+ feet of 22ga wire (~0.2 lbs). The crank wire on my Jeep is 16ga, so there may be room to downsize the crank wire as well, since the Northstar has a fairly modern gear reduction starter. There are mulitple switches on each pedal would could be replaced by single tiny logic level switches read by a BCM which communicates to the ECM and power distribution nodes over a CANBus (...kinda sounds like what OEMs are doing)... but I'm not super worried about doing all that on a Fiero.

I think that all that easy work has already been done on an F1 car

[ericjon262]

I guess the implication that I'm actually not going to tear the entire car apart to rewire the entire system to save 10-20 lbs was not sufficiently obvious.

Yes, I totally get the superiority of modern electrical design and understand that GM's design--AT THE TIME--was the cheapest way they could do it, not the best or lightest.

But since it's a tough concept... adding things--without also taking other things away--does in fact result in a weight gain

why not? I did it... sorta... and probably didn't lose 20 lbs...

[The Dark Side of Will]

Helped a few friends with a few things on Saturday.
Also, my dad owns a '73 GMC Motorhome that was my Uncle's, until he passed away in 2017.
It doesn't run well and the distributor has been seized in the block. We pulled the intake manifold for access to the distributor to start working on removing it. It's an OldS(*) 455 w/ TH425 trans.

Sunday I was able to get some mechanical stuff done. I got the starter cable stripped and marked for crimping. I installed 5x0.8mm screws to secure the electrical junction block, which let me fit the starter cable. I drilled and tapped the other hole in the alternator rear bracket. I turned down the threads on the GM crank bolt, liberated the washer, drilled it out for the ARP bolt and installed that pair with ARP moly assembly lube... I just need to call ARP to discuss the torque spec.

If it sounds like the mechanical tasks are getting tiny and fussy, that's because the mechanical tasks are getting tiny and fussy. I'm coming up to the completion of all mechanical work other than simple assembly.

I have drill next weekend, but I'm targeting having the harness design done, wire list done and main harness materials order delivered by the 4/30-5/01 weekend. Of course, I'll probably have to spend that weekend in POR-15 prison instead of working on wiring. I can also put the cradle up on a heavy duty cart that I've been using as a workbench, assemble the entire powertrain there and still have it at a comfortable height for building the harness. I'll probably do that, as seeing the engine off the stand, assembled to the transmission and on the cradle ready to go into the car will be really motivating for building the harness.


(*)OldSlomobile

[The Dark Side of Will]

Mouser has the Delphi electrical center datasheet:
https://www.mouser.com/datasheet/2/105/ ... 162073.pdf

And the product page:
https://www.mouser.com/ProductDetail/Ap ... ijhw%3D%3D

The Delphi Global Connection Systems catalog shows both modular (pg 312 of 404) and "traditional" (pg 326 of 404). The center linked above is one of several "traditional" configurations. I think it's common because it's the one GM uses with crate engine wiring harnesses.

All 27MB of the DGCS catalog can be downloaded here: https://www.tti.com/content/ttiinc/en/m ... talog.html

Also, the page on the 12146281 center cites drawing 12146337 to use for assembling the center. Snazzy!

Well... maybe not quite *that* snazzy. The Aptiv website is shit.

For example: https://www.aptiv.com/en/solutions/conn ... anguage=en
That page is supposed to display catalogs. It displays listings for connectors and terminals. Where are the rest? Why are they not in the list?
The "Resource Center" doesn't lead to any useable resources

And of course if I select "catalog" for electrical centers, this pops up: https://www.aptiv.com/en/solutions/conn ... al-centers
Where's the fucking catalog? There's no fucking catalog under fucking catalog.

Gaahhh, how did we as a species ever get beyond throwing rocks at monkeys?