World's slowest Fiero/Quad 4 Swap (Page 46/51)
Quadfather OCT 29, 07:57 PM
Started work on the engine wiring harness today, after reinstalling the last few parts of the engine. I don't remember how long it's been since I disassemble the IDI cover and related ignition pieces. Several years, at least. The Quad uses two coils that are held by a plastic housing attached to the underside of the IDI cover, with the ICM bolted under one end.



All the plugs on the Quad's harness were pretty dirty so it was time consuming to try to clean them before attaching the harness to the engine.



I labeled all the plugs when I removed this engine from my old GTZ in 2012, but in a couple cases I couldn't read my own writing and in others the labels either fell off or I missed a couple plugs.



This plug looks like it has a broken tang stuck in it.



This wire looks like it was pulled loose.



I'll dig out the wiring diagrams to identify these wires.
Quadfather NOV 18, 05:50 PM
Trying to figure out this wiring. Out of desperation I went to Facebook and asked for help from the Quad 4 group. Some of those folks know Quads as well as some of the people here know Fieros.


I trust most of this won’t be needed.



Most of my labels are good, while a few were either faded or stained so badly I can’t read them.



When I pulled the engine out of the GTZ in 2012, I didn’t label connectors I thought were obvious. The moral of the story is, label every connector. Figured out this one goes to the high pressure switch in the Quad’s AC line, which the Fiero doesn’t have.



The FSM is a big help. It doesn’t show quite enough detail to my liking, but it’s still helpful.



I’ve been cleaning the connectors with Clorox wipes to get the old oil and dirt off of everything. Next up I need to buy a bunch of loom of various diameters to replace this old stuff that’s dirty and brittle.

Also need to figure out radiator hoses, oil filter, and should probably buy new pigtails for the injectors. All three sets I have are worn out.

[This message has been edited by Quadfather (edited 11-18-2023).]

Quadfather NOV 23, 01:19 PM
Woke up to a dream that I got my Fiero running and my wife and I jumped in and went on a long trip. The car was running great, but somehow it was the original maroon color. Just as I started thinking I needed to post about it here, I woke up.

More progress. My new oil filter came yesterday. Funny how a simple thing like this can get you excited about a project again.



This is one of the long ones Bob Pease recommends.

[This message has been edited by Quadfather (edited 11-26-2023).]

Quadfather NOV 26, 08:34 PM
I've been spending a lot of time just sitting in the shop looking at the wiring harness (Beretta harness at the top of this photo, Fiero at the bottom):



Since I first began considering a Quad-to-Fiero swap more than a decade ago, I've been looking for step-by-step instructions for how to mate the Quad's computer and harness to the harness from the Fiero, but I haven't found one. Wiring is far outside my comfort zone so I have very basic questions.

I've read other swap threads many times, including those by Sardonyx247 and Fierobsessed. Many of the photos on Sardonyx's thread have disappeared, but the photo of Fierobsessed's finished harness is still there.



Fierobsessed described a bit of his process, so I'm trying to follow what I can. I'm just afraid of cutting or removing wires that I'll end up needing.

On the other hand, some of the choices ARE obvious, like the Beretta's ABS wires, relay and control unit.







Turns out one of the fusible links attached to the Beretta's junction block is toast.





It's been more than ten years since I last drove the Beretta and I don't remember having any electrical problem with the engine. I'll dig through the manuals to see what this one powered.

[This message has been edited by Quadfather (edited 11-26-2023).]

Quadfather DEC 03, 02:34 PM
Making cautious progress.



I realized I need the plastic organizer/insulator that holds the harness where it passes through the firewall. Had to use the heat gun to melt the sealant. Should’ve experimented on the Beretta’s first, but finally got both of them apart without too much damage.

Fiero unit is at the top, Beretta is at the bottom. The Beretta unit is about half an inch wider than the Fiero’s. Each one has a plastic “comb” to hold the wires.



The heat was hard on the Fiero’s comb, but it will still work

[This message has been edited by Quadfather (edited 12-03-2023).]

Quadfather DEC 03, 02:38 PM
I found a wiring diagram manual on eBay so while I wait for it to arrive I’m eliminating wiring from the Beretta harness that I’m 100% sure isn’t needed for the Fiero, like ABS brakes and airbags. In case you can’t read my writing that says “airbag actuator”.

[This message has been edited by Quadfather (edited 12-03-2023).]

Quadfather DEC 03, 09:02 PM
BEWARE the "terminal position assurance" (TPA) pieces on the C500s!

I’m pretty sure I’ve read every Quad 4 swap thread on this forum, as well as many other swaps involving other engines, but until today I’ve never known about the terminal position assurance pieces on the C500. I spent a good 45 minutes struggling to get any of the pins out of the Fiero’s C500, until one pin came out after its wire broke.

I did a Google search for “Fiero C500 removal problems” and finally learned of the existence of the terminal position assurance (TPA) pieces. Ought to be called PITA assurance pieces.









I feel as though I’ve passed some kind of initiation test, like I’m in the TPA piece gang now.
zkhennings DEC 04, 11:54 AM
Nice progress, good to know about the TPA piece as I will be repinning some C500 pins myself.

For the passthrough, you can actually stick them in a pot of boiling water and they will come apart very easily without any damage, did it recently-ish. Can't take credit for the idea though, Fieroguru had a nice writeup.
Quadfather DEC 04, 01:52 PM

quote
Originally posted by zkhennings:

Nice progress, good to know about the TPA piece as I will be repinning some C500 pins myself.

For the passthrough, you can actually stick them in a pot of boiling water and they will come apart very easily without any damage, did it recently-ish. Can't take credit for the idea though, Fieroguru had a nice writeup.



That sounds like a great idea.

Just found his write-up.

https://www.fiero.nl/forum/...100421-2-096720.html
Quadfather DEC 09, 09:28 PM
Didn’t get back to the shop until today, so not much progress to report. I left the C500 connectors from both the Fiero and the Beretta soaking in Jet A all week. It helped, but that GM sealant wasn’t giving up without a fight.





Here are photos of using the special unpinning tool to remove the wires from the Beretta connector (I did the Fiero C500 last week):





Not sure if the tool or something else caused it, but the tang on just about every pin was mangled. Cleaning off the sealant and then straightening the tangs and repositioning them was very tedious and very difficult to photograph.



When I started the process of plugging Beretta wires into the Fiero C500, I wasn’t sure which way the connector was supposed to be oriented. Then I discovered the connector is labeled.



I managed to get two wires installed in the connector, then was stumped because the connector on the wire is too big for the hole.