flexxedout88

ok i have a 92 camaro and i have gutted the tune port the computer and all out of the car and have a 600hp motor goin in it... just a carbbed sbc. im running a 4in fiberglass cowl hood and some vette wheels but becides that i want it to look as stock as possible... so i really wanna keep my stock guages but obviously they wont work without the computer... sooo what i need to know is does some1 make a factory looking dash with mechanical gauges??? or does any have any other suggestions?

camaronewbie

Stock guages work just fine without the computer!

JeffG3209

Always wondered myself. Thanks!!

Al Hasse

Not sure about the V8 cars, but the for the 90-92 V6 cars VSS is first routed to the ECM. The ECM then outputs to the speedometer, I would think the V8 cars to be the same. The rest of the gauges work independent of the ECM

flexxedout88

I was unaware of that I looked at a wiring diagram and it seemed they went from the sensor to the ECM then from the ECM to the gauge.... The gauges are electric correct? So I would haveto have all the guage senders and wiring... Which I don't have.... The car was an original v6 car... I don't much care about a speedo... Just wanna be able to monitor oil pressure temp and things on this motor with out having to gut my dash and make a gauge panal or har tacky gauges hangin on my dash somewhere. Also will the older style dash bezel mount in the newer style dash

camaronewbie

There may be a difference in the tuned port cars or the V6 cars. I missed the part about "i have gutted the tune port" so the ECM may have to stay connected for the speedo to work. On TBI cars there's no issues - the ECM can get taken out and guages work fine.

flexxedout88

ok awesome how so? what needs to be done to make the guages work without the ecm??? info please!

camaronewbie

Like I said, I have a TBI car, so I'm no expert - but I'd think as long as the ECM was plugged in, getting the positives and grounds it needs to simply function, that the guages would work as they should.

flexxedout88

Well I don't have the ECM.... Or the senders for the guages... So I would have to have all that for the guages to work correct??? Does ne one make a factory appering guage cluster with mechanical guages?

JTB91RS

I have a 91 RS which I swapped out the original 3.1L V6 for a carbed 350 sbc. I can't speak for the speedometer since it never worked as long as I've owned the car, but all of my other gauges just worked without having to hack anything in the dash. That said, I did retain many of the original V6 sensors as well as the v6 harnesses since I plan to swap TPI in later.

The temp gauge gets wired to a temp sensor on the driver's side head, and the oil pressure works off the oil pressure sending unit. The tach gets wired to the tach output on the distributor. The ECM should not be necessary for any of these gauges to function.

EDIT: I can't say for sure from experience since my speedometer doesn't work, but the ECM should have no affect on it's ability to operate. From looking at the wiring diagram, the signal from the VSS goes through the VSS buffer box where the speed signal is distributed individually to the speedometer, cruise control, and ECM. No wiring change should be necessary. Hope this helps.

flexxedout88

Hmmmm so if jacked all the senders for the guages and then made a harness from the undrer dash guage harness to the senders the guages should work??

JTB91RS

Yes, that seems to ne the case. If you have an opportunity to salvage the old engine harness too, it may be even easier to just hack it apart keeping only the wires and connectors that you need for those sensors.

flexxedout88

I no longer have the motor or harness... And I know I might not be right on sayinhis but if I'm wrong please correct me. For the guagues to wrk you would have to supply them with voltage as well as the sender with th corrct reference voltage which they would recive from the ECM... Right?

JTB91RS

I will have to double check the service manual, but I don't believe that the ECM that the ECM provides any reference voltage for these sensors. I think they are all reference +12v and/or ground. Unfortunately, I won't have a chance to check the schematics in the manual until tomorrow evening. I'll let you know what I find out though.

JTB91RS

One potential issue just occurred to me. The stock setup includes 2 temp sensors. One independently runs the gauge, and the other feeds the ECM. The ECM uses that reading to control the electric cooling fan, so if your setup re-uses the electric fan you will need to find another way to activate the fan. I'm pretty sure that I've seen other threads in this board before that give some work-arounds for that.

flexxedout88

That would be great if u could give me some details on the senders and referance voltages.. I would really like to get the factory guages runnin... And my chiltons is very very vauge.... And I was just gonna wire it with one of those universal poke in the radiator temp probe.

JTB91RS

I just got the chance to look at my Haynes manual, and it does show the instrument cluster being independent of the ECM. It looks like all reference voltages are relative to the 10A Gauges Fuse terminal and Ground.

Here's an overview of the wiring for the gauges:
Oil Pressure: +12v -> Cluster -> Tan Wire -> Oil Press. Sender -> Gnd
Engine Temp: +12v -> Cluster -> Dk Grn wire -> Coolant Temp Sender -> Gnd
Tachometer: +12v -> Cluster -> Wht Wire -> Ignition Coil output

And here's the idiot lights:
Brake: +12v -> Cluster -> tan/Wht Wire -> Park Brake SW && Brake Pressure SW && Ign SW -> Gnd
Coolant: +12v -> Cluster -> dk grn wire -> coolant temp sw && Ign SW -> gnd
Oil Pressure: +12v -> Cluster -> tan wire -> oil pressure sw -> gnd

The Voltmeter should already be wired to +12v/gnd assuming the cluster is getting power

flexxedout88

is there one wire that supplies power to the entire cluster or does each guage in the cluster get powered seperatly?? and if its each individual guage can i get a wire color for each guage that i need to send 12v to. thnak you again for ur help.

travis401

iTrader: (1)

flexxedout88

Ok so according to that. I would send 12 volts to both pink and black wires and then run the sender wires to their respective senders and then do I ground the sender or do I ground the ground wires on the harness?

JTB91RS

Thanks Travis! I've been looking for that connector diagram...

The sensors will each need their own paths to ground. If I recall correctly, some of the sensors (specifically, the temp sensor on the driver's side head) may only need a single signal wire for the signal to the cluster, though, as the sensor is directly grounded to the engine block or heads. Make sure that you don't use any kind of sealants, thread lockers, etc on those sensors to ensure they ground properly.

For the Tach, the only wire you need to worry about on the distributor is the white wire that sends a pulse every time there is an ignition pulse (4 pulses per engine revolution on a v8). The tach will work 'plug-n-play' like this assuming proper distributor installation

One note about the tach... if your original setup included a v6 as mine did, or if you use a cluster that came off of a v6 car, the tach will read high since it is expecting 3 pulses/revolution instead of 4. There are some good threads on the board describing how to fix that issue if needed.

travis401

iTrader: (1)

the black/pink wires are where your gauges are going to be getting their switched 12v from. theyre not hooked up to the engine harness so as long as your under dash harness wasnt trashed in the swap, you should have power to them already. the grounds are for the gauges, not the senders, and theyre already grounded. you said you didnt have the senders for the gauges, so for them to work youd need to install them, and then wire them to the appropriate wire in the dash to get the signal to the gauge. the easiest way to do that is to get a pinout diagram of your c100 connector, find the right wires for each sender, and wire them into it. heres a thread that should help.


on a side note, y would you trust stock 18 year old gauges with a 600hp motor?

flexxedout88

by chance could u link me to a thread on how to fix that cuz i will def have that issue since this was a v6 car. and also on the pinout diagram above where are those plugs located i see one says drive and one says pass. but i have two plugs that look like that both on the pass side under the dash that were originally plugged into the ecm... are those the same plugs or not??? and travis to ans ur question i am using the factory guages one because i wanna keep the car looking as stock as possible. two there is no clean way to put after market guages in the new dash without hackin it up which i dont wanna do and three i dont want to spend 700 bucks on guages. as long as i know it has oil pressure and isnt over heating that will work for me and i will hook some mech. guages up to it often to make sure all is well... the only after market guage i will have is a fuel press guage mounted under the hood so i can see it under the cowl thru the wind sheild.

travis401

iTrader: (1)

those plugs are the ones that go into the back of the gauge cluster.

JTB91RS

Unfortunately, I don't have any experience with the tach fix yet, so I doubt I can be very helpful with it. I still need to do this same thing to my car since I swapped out the original 3.1L engine for a 350sbc. Here's the thread for the tachometer fix:

https://www.thirdgen.org/forums/elec...meter-fix.html

You will either need to solder in some new resistors on the tach filter board, or else find a '91-'92 v8 car in the junkyard and salvage the tach filter board off of that.

Regarding your ecm, how many connectors originally went to it? I am pretty sure that my '91 3.1L has 3 connectors to the ecm (2 black, 1 yellow if my memory serves me correct) It might be more helpful to know what the original engine was and what model # the ECM was. Someone correct me if I'm wrong here, but I believe that GM used a few different ECMs in third gens, some with 2 connectors and some with 3, and there will be some differences in the pinout for the ecm harness.

The diagram that Travis posted is for the connectors at the back of the instrument cluster. If you remove your cluster, they will be attached to the dash assembly with one on each side of the steering column.

flexxedout88

mine orignally was a 3.1l v6 auto. and the ecm had 3 plugs one was teh under hood harness and the other two both cam from the driver side under the dash. and yeah i am gonna have to trac down teh right cluster idk about the whole sodering in the correct resistor. i shoudl have my motor and evetything in this weekned and hopfully i can get it runnin. and then im gonna get to work on these guages. im a hellava mechaninc but i sure aint no electrican. lol

flexxedout88

also there is no way for teh spedo to work without the ecm correct?

travis401

iTrader: (1)

i dont think so. the tbi cars ran the vss signal into a buffer box that fed the speedo and the ecm. the tpis and v6s ran the signal directly into the ecm. im sure you can wire in the buffer box from a tbi car to get your speedo to work though.

the bottom of post #3 of the thread i linked earlier shows what the buffer box looks like.

travis401

iTrader: (1)

if you dont feel like hunting the yards for a buffer box, i have a perfectly functioning one i could easily remove from my car....