Help with Rally Gauges
 

Some quick points:
- I've done my homework, I've spent some time in the 1st Gen Forum FAQs. I referenced this one heavily to get where I am: "Stock Cluster to a Rally Gauge Cluster" (http://firstgenfirebird.org/f-a-q/ca...d-instruments/)

- My car has been converted from Idiot Lights to Rally gauges by a previous owner, confirmed using article above

- All gauges worked previously to my most recent change, no guarantee on the readings but they worked, I am reasonably sure the Temp gauge was pretty close

- I have changed nothing about the way the cluster is wired up (yet)

I'm posting here hoping someone or the group can help me step through a troubleshooting process logically. I'd like to learn some things and do this right. I took Basic Electronics during Tech School for the Air Force in the early 90s and passed the class with a 98%. Now all that's forgotten and I can barely use a multimeter lol.

Problem occurred after I installed a new Dash Bezel (plastic one that surrounds the two pods). The one on the car looked bad and I bought a new one. All the gauges worked before I took them out. I took out the gauge cluster, remove the plastic bezel and also removed the clear plastic lens to clean them and polish them up. Reassembled everything with the new bezel and put it back in the dash. Nothing works. Not any of the gauges. Just the speedometer since that uses the mechanical cable.

Using the information I found in the article ref above I pulled the gauge cluster back out. First I verified the wiring for the 12-pin connector. It fits the cluster fine but the wire colors are completely wrong. I'm thinking it might be from a '69 Firebird. Maybe someone can verify. I also noticed every wire from the connector was spliced into a wire from the harness. Pretty much verifies someone changed the car from idiot lights to Rally gauges. Here's the wire map:

Pin 1: Tan Wire ---> Dark Blue Wire w/White Stripe (Oil Pressure Gauge)
Pin 2: Grey Wire ---> Two Dark Green Wires (the one grey wire is spliced to two Dk Grn wires) (Water Temp Gauge)
Pin 3: Black Wire ---> Tan Wire (Fuel Gauge)
Pin 4: Light Green Wire ---> Grey Wire (Illumination)
Pin 5: Two Dark Blue Wires w/ White Strip ---> Terminated and wrapped with tape, unused
Pin 6: Two Light Blue Wires ---> Terminated and wrapped with tape, unused (Illumination)

Pin 7: Dark Blue Wire ---> Light Blue Wire (Left Turn Light)
Pin 8: Orange Wire w/ Black Stripe ---> Tan Wire (Brake Light)
Pin 9: Tan Wire ---> Medium Blue Wire (Right Turn Light)
Pin 10: 2 Dark Green Wires (+12V DC)
First Dark Green Wire ---> Pink Wire from factory harness
Second Dark Green Wire ---> Light Blue Wire that goes to the firewall is spliced into a Black Wire w/ White Stripe that goes through the firewall into the engine compartment (I have not yet traced this wire)
Pin 11: Brown Wire ---> Terminated and wrapped with tape, unused (Volt Gauge)
Pin 12: Two Pink Wires ---> Brown Wire in the factory harness (Volt Gauge)

All the connections above (save for the Pin 10, 2nd green wire that runs to and through the firewall) are splices from the 12-pin connector directly to wires coming out of factory dash harness. If you reference the article above you'll see that the factory harness wires are spliced to the correct Pin in every case with the following exceptions:

- Pin 2 was connected to two green wires for idiot lights but only one for rally gauges. whoever did this conversion connected the Pin 2 wire to both green wires anyway
- Pin 6 is normally connected to a 2nd gray wire for cluster illumination whereas here the wires from this pin were just terminated and not used
- Pin 10 should only be a single Pink wire. Whoever did this conversion connected the two green wires coming out of this pin on this connector to the Pink wire and the Light Blue wire that runs through the firewall into the engine compartment
- Pin 11 should be a White wire used for the Volt Gauge, whereas the brown wire coming from this pin is terminated and unused
- Pin 12 should be a Black wire used for the Volt Gauge. The two Pink wires coming from this Pin are spliced into the Brown wire coming from the Factory Harness that was used for the Generator light in the Idiot light setup. According to the article this Brown wire runs to the Voltage Regulator so I suspect this is how they were getting the Volt Gauge to work.

I know this was not done in accordance with the article I mentioned above BUT please remember all the gauges worked previously. Could it be done better? Yes. In the long term I will probably replace the engine side and dash harness both to make the car correct for Rally Gauges. Right now I'd just like to get the gauges working again. Whoever did this, did install sending units and made the necessary changes on the engine side to get the gauges to work as they worked before.

For a ground the same person (presumably) ran a black ground wire from the upper rightmost bolt that is used to hold the PCB in place on the cluster housing to a bare metal spot on the firewall. I figure most or at least some here in the forum will suspect a ground issue. I don't disagree but will need some help chasing that down. I don't fully understand yet how the 12V DC is used within the cluster and how to measure it as it works through the PCB for the cluster.

By the way, the PCB has two bad tracks that someone soldered (I have ordered a new one from our sponsor), however the tracks in question are for the left and right turn light or brake light. I traced them. Should not be a factor for the gauges, esp considering that, as I have mentioned, all the gauges worked before I pulled the cluster out.

So things I've done:
- checked the fuse and it checked good, 0.00 resistance on the multimeter AND I replaced it anyway
- verified exactly how the 12-pin connector is installed in the cluster. I didn't know this at first because when I removed the connector I couldn't see how it was oriented. Researching here I found Pin 1 must be in the upper left corner so that pins 1-6 are on top running left to right and pins 7-12 are on bottom running right to left. I was amazed at how many diagrams and other references I looked at that had the pinouts for the Rally gauges but did not say which way to install the connector.

- changed the fuse, verified I had the 12-pin connector installed correctly, turned the key to accessory and also started the car, none of the gauges functioned

- I removed the connector and put the key back to accessory and checked Pin 10 where the 12V DC is supposed to come in and got 12.74 on the multimeter

That's where I have stopped for now. The wires are long enough in the dash that I can connect it to the cluster without having to stick the cluster back in the dash so I am hoping this will help with troubleshooting. I'd like to get the gauges working again and then I'll see what I can do to clean up the wiring.

Appreciate any help offered.

Does your high beam indicator work? The reason I ask is that it relies on the same ground, but a different power circuit so that should confirm or eliminate the ground problem.

I created pinout images for the dash to cluster harness connectors a while ago. Unfortunately, I didn't post the ralley gauge pinouts. I've since lost the files due to a computer crash.

http://forums.maxperformanceinc.com/...&highlight=u30

The first thing I'd do is beef up the ground. Electronics need a common ground to work. If the ground is intermittent or not solid, your gauges won't know where circuit common is. Get a braided wire and find ground on the gauges. Run that point to the body and make sure the connections at each point have a clean surface. Once that's as solid as you can make it, finding a problem will be much easier to diagnose.

I was just messing with a cluster so I have a dirty old spare to snap a pic of.

When you say you swapped bezels the first thing I thought of was the ground strap... Did it get left out?

It has to be ground if none of them work. Sounds like you need to ground the housing and not the PCB

look at this pic for a reference.

Good question. I know the high beam indicator has the little metal arm that goes to the rear of the cluster and bolts to the ground. I made sure this was put back in place correctly but I don't think I ever tried that. I'm working on it tonight, so I will try and let you know.

Thank you!! Appreciate that. Much easier than my line by line pinouts, lol.

Yeah, I'm overdue to post some pics. I know its much easier to help with these posts if pictures are posted.

In case anyone can identify where this 12-pin connector came from here is Pin 1 through 6 (pin 1 is on the right):

http://i219.photobucket.com/albums/c..._45_28_Pro.jpg

Here is the other side, pin 7 is also on the right:

http://i219.photobucket.com/albums/c..._46_02_Pro.jpg

Here is the factory harness spliced:

http://i219.photobucket.com/albums/c..._48_00_Pro.jpg

Here is the ground the person that set this up ran. They bolted it to the body behind the pedal support rod:

http://i219.photobucket.com/albums/c..._46_33_Pro.jpg

And the other end, this loop:

http://i219.photobucket.com/albums/c..._46_46_Pro.jpg

Is attached to the gauge cluster here:

http://i219.photobucket.com/albums/c..._05_08_Pro.jpg

And to answer your question, Donovan, that ground for the tab you pictured is installed:

http://i219.photobucket.com/albums/c..._04_46_Pro.jpg

So given the circumstances of the problem and what I've learned I almost have to believe the either A) I missed something when I re-assembled the cluster and re-attached it to the plasti bezel or B) I missed something when installing the cluster assembly back in the dash.

As for the grounds I did reconnect the ground wire running to the body shown above and I made sure there was a screw for the upper middle hole (where the metal ground tab runs) to connect the ground tab to the top of the metal dash.

So I think I have two good grounds here and I am fairly certain this is how it was hooked up prior. Connecting the 12-pin connector nothing works. So if someone knows how to do it, I'd love to know how to step through the gauge cluster with a multimeter to figure out what is going wrong. I know there is 12v on Pin 10 and I know the cluster is grounded and I know there is nothing wrong with the senders and their grounds. The PCB is a common denominator but it was working before the bezel change. How could I test with a multimeter to verify the PCB is working?

Need a better picture of you splice. Is it color to color for all the wires?

Since you say these gauges were added to a car that did not come with them from the factory. Don't know if you are aware of this or not but on all 67 and 68 Firebirds, if the car was ordered with rally gauges, BOTH the entire dash and engine compartment wiring harnesses are specific to w/rally gauges. There are some major differences in the wiring on this car especially a car with in dash gauges. Judging buy some of your photos somebody did the conversion rather poorly. If you want this right I would order 2 brand new reproduction harnesses. One for the dash and the other for the engine compartment. As long as the gauges worked before, as you stated (we can hope the dash cluster is in good working order). In one of your photos I can see that both of the copper pathways that feed 12-14+ volts into and out of your amp gauge have gotten hot. The PC looks to be original to this set. I would replace the printed circuit at the same time as the wiring.

It's time to do this right! Make sure that when you order your new wiring you tell them "with rally gauges."

That way you will have peace of mind knowing that all the wiring is brand new.

One of the light sockets was reserved for the fiber optic cable to the ashtray. FYI

I usually use dielectric grease on the plug to keep from damaging the flexible circuit board.

Your Plug layout doesn't seem to follow my notes for either a stock cluster or Rally cluster. From my notes I have the following.

Stock idiot lights
1 Light Tan - Fuel Gauge
2 Green (2 wires) - Water temp
3 Gray - Gauge lights
4 N/A
5 N/A
6 N/A
7 Pink (2 wires) +12v
8 Blue/Whilte Stripe - Oil pressure light
9 Light Blue - Left Turn signal
10 Dark Tan - Brake Light
11 Brown - Generator Light
12 Medium Blue - Right Turn Light

Rally cluster
1 Blue/Whilte Stripe - Oil pressure light
2 Green (2 wires) - Water temp
3 Light Tan - Fuel Gauge
4 Gray - Gauge lights
5 N/A
6 Gray - Gauge lights
7 Light Blue - Left Turn signal
8 Dark Tan - Brake Light
9 Medium Blue - Right Turn Light
10 Pink (2 wires) +12v
11 White Amp gauge
12 Black Amp gauge

So you said this worked before. I don't see how it it did based on looking at the plug but again what is going on with the splice. most of it is hidden by your hand.

I have some hand written notes and drawing. If your interested send me a PM with your email address and I will send them to you.

As looking at the back side of the cluster where the plug goes the pins would be:

1 2 3 4 5 6

12 11 10 9 8 7

Your finger is pointing to the 4 5 6 pins that are all tied together for the gauge lights (Grey wires).


ON the cluster Pin 10 (Pink wire)has +12V. It feeds one side of the oil, fuel and temp. I can easily see this path on your pic. It also feeds the left and right blinker. The other side of the oil, fuel and temp go to the sending units that are then grounded. Same with the Left and right turn signal they go to the lights and then grounded by the turn signal switch in the steering column in order to complete the circuit.

The amp gauge is a circuit all by itself. Be careful with that one if you decide to use it. Both wires would have a full 12 volts. One from the junction by the battery and one by the Alternator. There is a very small difference in voltage between the two points thus a small amount of current that allows the amp gauge to work.

Hope some of this helps.

No, the colors for the 12-pin connector are completely different. Not correct for either idiot lights or rally gauges so I don't know where they got it from. The factory harness wires are mapped to the correct pins with a few exceptions. Like I said, everything worked with this harness setup before so I doubt its a problem with the harness or the wiring. Here's the mapping again, left side is wires coming out of the 12-pin connector, right side is the factory harness wire that the connector wire is spliced to:

Pin 1: Tan Wire ---> Dark Blue Wire w/White Stripe (Oil Pressure Gauge)
Pin 2: Grey Wire ---> Two Dark Green Wires (the one grey wire is spliced to two Dk Grn wires) (Water Temp Gauge)
Pin 3: Black Wire ---> Tan Wire (Fuel Gauge)
Pin 4: Light Green Wire ---> Grey Wire (Illumination)
Pin 5: Two Dark Blue Wires w/ White Strip ---> Terminated and wrapped with tape, unused
Pin 6: Two Light Blue Wires ---> Terminated and wrapped with tape, unused (Illumination)

Pin 7: Dark Blue Wire ---> Light Blue Wire (Left Turn Light)
Pin 8: Orange Wire w/ Black Stripe ---> Tan Wire (Brake Light)
Pin 9: Tan Wire ---> Medium Blue Wire (Right Turn Light)
Pin 10: 2 Dark Green Wires (+12V DC)
First Dark Green Wire ---> Pink Wire from factory harness
Second Dark Green Wire ---> Light Blue Wire that goes to the firewall is spliced into a Black Wire w/ White Stripe that goes through the firewall into the engine compartment (I have not yet traced this wire)
Pin 11: Brown Wire ---> Terminated and wrapped with tape, unused (Volt Gauge)
Pin 12: Two Pink Wires ---> Brown Wire in the factory harness (Volt Gauge)

Peter, thanks for the recommendations. I am aware the wiring is different. Now that I know the car was converted this way that is exactly the long term plan. But ordering all of that AND installing it is going to take some time. I'd like to get the gauges working again as is for the short term so my wife can drive and enjoy the car.

I'm working to order a new PCB from Ames but have been having some issues with that. So that will happen in the short term but I don't have a new one in hand to test with yet.

OK i'm following your pin-out now.

So you really got two separate voltage feeds.
1. You gauge lights
2 your gauges.

Since you say you have 12 volts on both of those lines I would suggest connecting up the plug and seperate ground and then use your volt meter to verify voltage to the gauges along the trace. Should be able to do the same for the gauge lights. put your ground for the meter on the case of the gauge pod.

Only way I see that all gauges would not work would be no power to them on the flex circuit board.

Thanks rohrt. About to test that now. You mentioned there should be two 12v sources. I know Pin 10 supplies the 12v for the gauges. Which pin supplies the voltage for the lights? I can figure it out here shortly. I'll hook up the battery and just put the multimeter on each pin before i plug it into the cluster.

Well, pretty confident I found the problem.

http://i219.photobucket.com/albums/c..._19_02_Pro.jpg

I decided to start tonight by doing a basic continuity check using the multimeter of the two tracks on the PCB with the obvious solder work. Those checked out ok so I figured what the heck, go ahead and check em all. Glad I did because where this break was and how close it was to the edge of the PCB made it very hard to just see. Once I got the open indication I started poking around in there with a flashlight and then it became pretty obvious. The track that is complete separated leads back to Pin 10 and is the 12V to all the gauges so certainly makes sense.

Took the time to test all the bulbs too with the 9V battery and those were all good.

Unfortunately, since the gauges all worked before I think I get the dumba$$ award here. I must have snagged the PCB on something and broke the tracke while re-installing it.

Jimmy, everything looks correct to me as far as wiring goes (I wish the splices were soldered together instead of what looks like just twisted and taped). May I suggest moving your extra ground (ring terminal) wire to one of the case screws instead as it may be lifted off the circuit board (not touching the inner layer) enough to not get a good ground.

As you can see from the diagram the plug is shown as a mirror image as to how it's plugged.

Yup, I can see the break clearly.

Ames sells this part under PN FM850G for $82.
https://secure.amesperf.com/qilan/De...art_num=FM850G

Thanks HFR!!!

Installed the new PCB this weekend. Fuel and temp seem to be working well which is a huge relief. I don't think the Voltmeter is working at all but not surprising given the Frankenwiring. And the Oil Pressure Gauge pegs at 80. When idling down it sometimes drops a bit but we went on a long drive Friday night and it stayed pegged. I'm going to try a new sending unit (unless someone knows who to test one with a multimeter) but I this could also be attributed to the Franken wiring. I've added two new wiring harnesses to the to do list.