Some quick points: - I've done my homework, I'm aware there are some threads on problems with gauges in the FAQs. I referenced this one heavily to get where I am: "Stock Cluster to a Rally Gauge Cluster". Read some of the other threads as well - 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 I can barely use a multimeter <sigh>.
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 here 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 verified 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 here 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 a Rally Gauge car. 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 AMES), 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.
