The optional ralley gauge pod can be found on most later model fastback GT's and Formulas. This package used a slightly different tach too and sometimes even a 120 mph speedo. I bought a good working set of ralley gauges at the Mall here on the Forum, but I've seen at least one set in the boneyard once too.

You need locate the whole pod (including the wiring harness plug and at least enough wire to splice into), or better yet, the entire 5 wire pod harness with both end connectors attached. Here is how to wire it in once the gauges are physically mounted. Installing them requires removing the console and carefully cutting some holes, or better yet, grab the whole middle console part when you buy the ralley gauge pod so that you don't have to modify anything.

I referred a lot to the "Big Fiero Parts Book" when I was doing my ralley gauge swap and it worked like a charm, so I'm going to heavily quote them in this post (hey, why re-invent the wheel). Most later model Fieros will have the correct plug for the pod harness tucked away unused somewhere under the dash, but for 84-85 cars you must splice into the existing harness like described below.

First, make a wiring harness from the existing plug and trailing wires, hopefully about 6 to 12 inches long (15-30 cm). There will be five wires: brown, pink with black stripe, tan, black, and gray. I dug around in my shed until I found approximately 2 foot lengths (60 cm) of each of these color wires (14 gauge wire for the power and ground, but 16 gauge will work for the rest).

You can use any color wire, but it'll be more professional looking and easier to work on in the future if you can color coordinate as much as possible. Splice the 5 wires onto the connector leads and electrical tape most of the wires together for neatness, but leave the end leads unwrapped so you can work with them.

Remove the plastic trim piece that covers the back of the main instrument cluster. Unplug the big main connector (C3) on the right side of the instrument cluster (behind the tach area). It should have about 16 pins in this connector labeled 2-18 on the plastic.

C3 connector-----ralley gauges----wire usage

Pin #6, brown-----Pin #1, brown-----alternator field signal
Pin #5, pink/blk---Pin #2, pink/blk---12v switched power
Pin #17, tan------Pin #3, tan-------oil pressure sender
Pin #11, black----Pin #4, black-----ground for ralley pod
Pin #3, gray------Pin #5, gray------power for pod lights (dimmer switch)

[This message has been edited by batboy (edited 11-28-1999).]

batboy--I'm trying to buy an '85 GT that has (I think) the rally gauges. But I want to transfer everything over to my '86 2m4. (Long story) I'm installing a custom dash (if I ever get it finished) and plan on keeping the original gauge cluster for now (at least until I can afford Cliffs' gauges). I have the 85 mph speedo and stock (of course) tach. Would I have to change the speedo and tach or will these work alright? Like I said, eventually I will have Cliffs' gauges. I don't want to spend any more $$ right now, but I would like to install the rally gauges in the new dash. Last, how do you tell if the wiring harness is already installed in the car. My car didn't come with the extra gauges, but it is an '86. If I do have the wiring harness already installed, will the gauges be plug n play?

I don't think 85GTs had the extra gages at least mine didn't

Thanks batboy,I have a set of optional gauges and instrument cluster coming. I was wondering how to hook them up. You answered my question before I could even post it. No wonder this is the best Fiero site one the web!

I don't think any 84 or 85 originally had the ralley gauges, but a previous owner may of installed them.

Monkeydude, it's ok to use the existing speedo and tach. I'd disconnect the original oil pressure gauge built into the tach and just use the ralley oil gauge. I tried running them both, but the two oil pressure gauges acted goofy and the needles bounced all around. I could use one or the other, but not both at the same time. I don't know, maybe the wrong resistance if both gauges were used together.

Most of the later 86 models had the ralley gauge harness, but I don't know if all the early 86 Fieros did or not. Remove the center console from the shifter and on forward. Reach under the dashboard and locate an unused six pin connector with five wires running to it (see above post for what color wires).

If you find this connector, then the ralley gauges are plug and go. I was working on a 85, so I had to splice in the wires, but it was not hard, and I'm not all that great at auto wiring. I'm even worse at home wiring.

Batboy--just looked under my dash for that extra wiring harness. (Glad I had my dash apart!) I didn't see it, so what is the "C3" connector? I assume its one of the ones that connects to the regular gauge cluster?

There are three wiring harness connectors going to the main instrument cluster. One plugs in underneath and on the left side {actually into the speedometer module) and two connectors plug into the back of the instrument cluster panel itself. The right rear connector (referred to as C3 in some wiring diagrams) is the one you want, the one right behind where the tach sits, the connector with the most wires running to it. There are a couple little "hooks" on the connector that must be released before the connector pulls out.

my 85 GT and 85 SE both have the extra gauges....

Just when you think you're getting these cars figured out, a couple of 85 Fieros just gotta prove you wrong. I wonder if those ralley gauges are original or if they were added on later? Neither one of my 85 SE or 85 GT Fieros have the extra gauge pod wiring harness. Regardless, I really like the ralley gauges once I installed them. After you get the wiring figured out, it's not a hard swap to do. Even better if you can find the 120 mph speedo and matching tach.

After asking Batboy's permission, I've modified his article slightly (just changed the picture and put the wiring info in a table) and added it to the Fiero Project.

http://www.digitalfusion.on.ca/fiero/gauges.htm

Kick Hill (www.kickhill.com) has the rally gauges for $20. Don't know if they come with the wiring harness or not.

Batboy,i just got a set my set of rally gauges but it didn't have the plug coming from the gauges. Could you tell me which wire goes to which pin. I'll try to make a plug. Or if anybody out there has a plug that they doesn't need,I'll buy it from you. Thanks,ggarsk

HEY! I called kick hill (yesterday) about ordering the rally gages, and the guy on the phone told me that dispite what thier web site stated that the gage's were $100.00. So if you guys know anyone selling a set cheaper pleas let me know. Thanks

Ok I guess I dont see exactly why the rally gauges are "great". I like the looks of it, but I have an oil press gauge in the Tach gauge, so I am just missing the voltage gauge. Is there any advantage to the rally gauge besides having a voltage gauge? (I must admit hate idiot lights, but ive never had a use for the in dash volt gauges that were in my other vehicles, and with the oil pressure gauge in the tach it is easier for me to glance at)

I will be selling them on my site. $40.

The reason I added the ralley gauges in my Batmobile was because the old 85 mph speedo didn't work and the tach was really out of wack with the V8, so I replaced them with aftermarket 120 mph speedo and 8,000 rpm V8 tach.

Some Fieros do have an optional factory 120 mph speedo and the tach used with the ralley gauges do not have the oil pressure gauge within it. Greendano (I wonder what ever happened to him?) said he just removed the tach oil pressure gauge needle and then covered the numbers up with a piece of electrical tape.

Tom,Would you happen to have a extra plug for the rally gauges. I am in desperate need of one.

Hey ggarsk, I'll go out tomorrow morning and check out the order of those wires for you. You might be able to find one of those plugs at a well stocked auto parts store, I think they're a generic GM 6 wire plug. If you do, I'd take your gauges with you to double check and make sure it does fit.

batboy, I got an email from Dan-O a couple days ago. he sold his yellow 85 GT and now has an F40 kit he's working on!!

I'll be posting photos of his kit and progress to my website very soon.

It looks like the 120MPH speedo and the rally guages were added in '86. In '86 the v-6 SE got the rally guages, but kept the 85MPH speedo. The GT got the rally guages and a 120MPH speedo. In '87 and '88 Feiros, all v-6 equipped cars had the rally guages and 120MPH speedo. Apparently there was no 120MPH speedo or rally guages in '84-'85. All information is from my Fiero spotters guide.

Thanks batboy,i'll check out part stores forthat plug. Have a great weekend!

GG, it looks like the brown wire that is supposed to go to pin #1 on the ralley gauge plug is closest to the passenger side. I couldn't drop the plug out without taking the whole console off again, which I didn't want to do right now (we had about 3-4 inches of snow that fell last night and unfortunately the Batmobile is parked outside at the moment). Does anyone else have a gauge plug readily accessable they can look at real handy to confirm this? Maybe Tom?

Batboy,

I found the post you mentioned in my question on resetting the odometer.

Thanks

Batboy,I got my rally gauges in...almost. But my C3 connector doesn't match up with the one you explained. The #6 pin is tan and there is no wire in the #17 slot. There is no solid brown wire in the C3 Should I hook my tan wire from the gauges to the #6 tan. And where do I find the brown wire? I want to get it back together....2 weeks without it is driving me crazy!! BTW it's an '84 SE

GeeGee, are you sure you have the correct connector?
Haynes, page 288 bottom circuit shows the rally gauge wiring, and the oil pressure sender definitely connects to C3, Term.#17, and is a Tan wire.
You must have an oil pressure Gauge in your pod. It has three terminals on the back, connecting to the copper traces on the flexible printed circuit board. See if you can follow them:
one is hot (+12V) and comes out on Connector C2 (not C3!)terminal #9, pink/black:
one is the ground, and comes out at C3, Term.#11 and is black,
and the one of interest, from the sender, comes out at C3, Term.#17 and is the tan wire.
Don't connect to any other wire...you must be certain or you could damage your new gauges, or worse!

Its interesting to note that the voltmeter is right across the hot and ground...so these wires could be picked up from the fuse panel at any switched fuse. Hope this helps, and hasn't put you off. I'd hate for you to damage those rare gauges.

GG, this has me puzzled. The number 6 brown wire could of easily faded to a tan color, I've seen plenty of red wires that faded to pink. But I sure can't explain why there is no tan wire in number 17. To make sure the #6 wire is for the voltage gauge, turn on the ignition without starting the car and put a volt meter to that wire. It should read between 12 to 14 volts. The sender unit wires have to be tested using an ohm meter with the car running. The sending unit wires shouldn't have voltage running to it, especially if the car is not running.

While looking stuff up for this question, I did run across this tidbit of news. According to "The Big Fiero Book" if you install the ralley gauges into a 1984 Fiero, you MUST change the oil pressure sending unit. Sorry I can't be of more help. You are working on the correct wire plug, right? It should be the larger (more wires) of the two that plug into the back of the dash on the right side as your sitting in the car.

I think I found the problem. Aparrently the 84 wiring is different. According to the Pontiac service manual,the oil and temp warning lights are on the same circuit...the tan wire in the #6 slot. So maybe you have to rewire the oil sending unit so it is on a seperate wire. I know I'll get it figured out with the help from the forum members. Thanks for all your help.