What are some relatively straight-forward digital instrument cluster swap options that won't cost an arm and a leg? My speedometer gauge unit is no bueno, so I figured might as well consider a cool upgrade. The S10 digital dash looks like it would be pretty cool, but I don't know how much wiring and sensors have to be changed. Tom's Digital looks pretty cool, but not particularly cheap. Perhaps I could just do the speedo and tach. Intellitronix looks similar. I'm also considering building something of my own using an arduino or similar. Reading the VSS input seems simple enough, but building a display that captures that '80s retro-futuristic vacuum fluorescent look would be tricky. The coolest swap would be S2000, but going from Honda to GM sounds like more work than I'm trying to dedicate to this car.
[This message has been edited by statue4 (edited 12-21-2020).]
That looks awesome! I'll keep my eye out at the local junkyards for one.
Side note: The closest yard to me is LKQ in Wilmington, CA and I don't like it nearly as much as some of the yards back in Denver. If anyone has salvage yards they like to go to in the LA area, let me know. I've been meaning to swing by one in Oceanside that supposedly has a Fiero, but it has been there since October so I'm afraid the parts I need will have already been picked off. Oh well.
Just make sure that whatever route you choose, the cluster has all of the same warning lights as the Fiero......mainly the "check engine" light. You know all to well about California smog
Haha true! If all goes as planned, I'll register it out of state and swap the engine by the time my next smog test is due (but we know things never go as planned). While more lenient on swaps, I'd guess some other states will still want a working CEL.
I went to a junkyard today and picked up a few things. Primarily went to get a set of sun visors, but also picked up a center console, original radio and original speedo from a Fiero. I also grabbed the digital dash cluster from a 1994 Oldsmobile Bravado. The image is just a reference image: I have not applied power to mine yet, so it might not even work. I did not think to grab the VSS or anything from the Bravado.
So I'm working on the digital Bravada (same as Blazer, S-10, Jimmy) dash install and it is going well so far. I re-flowed the power supply solder points before even trying to fire it up, because it is a common point of failure on these things.
I added spade connectors to the Bravada harness pigtail and connected it up to the Fiero harness with T-connectors, retaining the original Fiero connectors so I can switch back to the Fiero dash if I want to.
I compiled the Fiero and Blazer wiring diagrams into this quick connector pinout diagram:
Incase it gets compressed and hard to view: https://photos.app.goo.gl/cmMPRR4QBou5yW9D7 I have two questions about the wiring: 1. The digital dash has a pin for "Lights on signal." What do I do with this? I'm guessing it reduces the brightness when the headlights are on? Even though I connected the grey dimmer wires, all that happens when I turn the dimmer control down is that the display starts to flicker. 2. How do I connect the VSS? The Fiero diagram shows three important (sounding) connections: speed-sensor low, speed-sensor-high, and speed output to computer & cruise control. The digital dash only has one speed sensor input connection. How should I tackle this? I actually haven't even looked into if the Bravada/Blazer/etc used a 4000 pulse per mile VSS like the Fiero or a different number of pulses per mile.
Got the wiring done. Now all I need to do is get a nice looking semi-transparent plastic faceplate. For those questions I had: 1. The dimming works fine. I connected that "lights on signal" wire to the brown wire from the headlight switch. 2. I think I got the speedometer hooked up okay. I connected the speed sensor hi from the C1 speedometer connector to the Bravada light blue and black speed sensor wire. I hooked the speed sensor lo from the C1 connector to ground. Still have nothing going to the speed signal to ECM, but I have been driving the car for months wiithout a working VSS anyways, so no difference there. Because I still need the plastic VSS gear I can't test the accuracy of the speedometer, but if I take the VSS and spin it with my hand the speedometer will show change. How important is it for the ECM to know the vehicle speed? Would it run better? I guess I wont have cruise control unless I figure that out either.
It will look alot better once I get a faceplate figured out.
So the digital oil pressure always reads at 80 psi when the engine is on, but the stock one is still installed. I'm guessing I will have to replace the oil pressure sending unit with one from a S-10/Blazer/Bravada/etc. for it to work properly. I've been looking into the speedometer and it looks like the ECM & cruise control input is actually 2000 ppm instead of the speedo's 4000. So the stock speedo would receive the 4000 signal from the VSS and then output a 2000 signal to the ECM. I think for this to work properly I will have to send the VSS signal to the digital dash AND to a stock Fiero speedometer so it can step it down to 2000. The stock Fiero speedometer would have to be hidden under the dash somewhere and would only be there so it can output the proper signal to the ECM and cruise control. I wonder if I could disassemble the stock speedometer assembly a bit to only include the necessary components for this. For now it does not matter, since I still need a plastic VSS gear. Does anyone know what the ECM does with the speed info? I've driven it for months without, but perhaps it will run better once I get that sorted. Gas gauge: I know people usually run out of gas when their gauge says 1/4, but mine has been a bit different. Perhaps because I used a generic sender from Summit. With the stock cluster a full tank of gas would read as about 2/3 on the gauge and empty would be way underneath zero on the gauge. With the new digital dash it is accurate at full and zero! Sweet! But I think the float gets stuck in the down position because after I fill up it will not change the reading on the gauge until I hit a pothole or bump. I still need to get some Lexan or something as a faceplate. I don't really see where I will be able to attach it but I will cross that bridge when I get to it.
if you find a 88 speedo there is a post somewhere on here about putting a firebird gauge cluster in a fiero. It has all the points on the board you would need to get the speedo from the ecm to the fiero speedo board then output 4000ppm to the digital cluster but if you turn on cruise or the like the ecm still thinks it is using the fiero speedo as a display so it provides th correct output back to the ecm. I did this with my syclone setup. The oil pressure gauge has to do with the sensor and you might have to put a different sensor on the engine and run a wire all the way to the gauge cluster to work correctly