Hey guys so I was working on my car heater fan and the ground plate for the lighter accidentally touched the fan switch and sparked. I now do not have power to my center gauge cluster except for the battery gauge and instrument lights. There is no power coming from the wire harness except for the pink wires. Also when this happened my tachometer flipped to the opposite side and is stuck there and now the heater fan does not turn due to the fact that the ground wire when tested with a test light no longer lights up like it use to. Checked all the fuses and they are good. Please help I am so lost :/

 

saouad.. I can help you.. but its late and I need rest.. I'll take a look at this soon.

 

Did you visually check the fuses, or do a connectivity test?

 

I did check the fuses with a test light on both sides if each fuse. I went ahead and replaced the fuse for the gauges and for the ac/blower and still no luck

 

ok so i went out to my car this morning and the fan started to work, how i do not know, it still doesn't work on high lol. so I went ahead to check if any power going to the center gauge cluster but no luck other than power from the pink wires so my gauges still don't work other than for the battery gauge and instrument lights. I manually flipped the tach to the other side and appears to be functioning normally.

 

I went and checked the wiring harness that plugs into the flexible circuit board for the center gauge clusters and found my test light, light up for wires labelled numbers 4,6,and 11 only on the wire harness. all others show no signs of lighting up my test light (1,2,3,5,7,8,9,10, and 12)

 

anyone?

 

Next time... remove battery wire before working on electrical issues. That is one of the primary reasons that I installed a battery disconnect switch. You are fortunate if you did not fry a fusible-link.

 

I had disconnected my battery but I reconnected it to try my fan switch and me not paying attention let the ground wire of the lighter to contact the fan switch.... Very stupid on my part. But my fan switch still works so you think anything happened to the gauges? It didn't touch any of the cluster gauge wires but I am not that good with electrical so when I get this back to working all my electrical will be working so I won't have to touch anything again lol any diagnosing help will be greatly appreciated.

 

Did you ever figure this out? I lost a good friend last weekend and took some time away from here.

The pink/black wire on your 81 (I had to look at old threads to find this) is the power wire for the gauges. If looking at the back of the cluster it is the second wire down on the left.. You should have power on this wire when you turn the key on... The tach is powered by this same pink/black wire.

The second pink wire in your connector is the check engine soon light I believe, I've not looked at a schematic yet.

Have you checked the tabs on the printed circuit board (PCB) to make sure they have not separated from the board?

 

I am very sorry to hear about your good friend. I offer my condolences. the printed circuit board appears to be in great shape no tabs separated from the board. I believe i have power going to the pink/black wire i believe its labelled number 11. after replacing every single fuse I did notice my low fuel light came on so i will have to add some gas, and as for the oil pressure gauge it was pegged all the way to the right so i took apart the cluster and manually placed it to 0. I am going to test my gauges tomorrow and hoping for a lot of luck, I will keep you updated. but please correct me if I am wrong about wire labelled number 11 on my harness for power (if I am reading the above diagram correctly the left side being 6-12, 6 at bottom and 12 at top and the right side 1-5) because that would be great news before I try going and looking for anything wrong in the wires. Again

 

Thank you...

Now to your gauges.. If you have power on the pink wires, you don't have a power issue.. your stated that your oil pressure gauge was pegged to the right with the key on.. Placing it to Zero will do nothing because when you turn the key on it will go back to pegged.. You are missing ohms input not power.

What are the other gauges doing.. I'm going to guess the temp gauge is at cool, the oil pressure is pegged and the fuel is full?

All three are symptoms of missing input ohms to the gauge. So on your oil pressure gauge.. go to the sending unit and pull the wire from it.. ground this wire out and see if the gauge goes to 0 oil pressure. If it does, then you more than likely have an issue with the sender and not the dash unit.

On the low fuel lamp.. make sure you have the module in there.. if you have just a socket the lamp will stay on all the time. And because some intellectual genius decided to change how we post pictures here.. for some reason they are not posting.. but the module looks similar to the one at this link

http://willcoxcorvette.com/product_i...ducts_id=27533

Willcox

 

ok so my fuel gauge reads empty because there is barely any gas in the car, the oil pressure gauge reads pegged all the way to the right, and my oil temp gauge and my coolant temp gauge go to zero when car is on, I pulled the black wire that plugs into the oil switch and grounded it and it still says pegged. also i do have the module for the low fuel.

 

ok so i filled my car up with gas and started it for about 10 minutes, the gas gauge and battery gauge both work but the oil temp, coolant temp, and oil pressure gauge do not. the coolant temp and oil temp remain at zero while the oil pressure gauge is pegged to the right but moves further down when the car is started.

 

ok so now none of my gauges work so i ordered a new printed circuit board, when i wiggled the harness in the back i saw the voltmeter jump so I figured I have a bad circuit board, could this cause the oil pressure gauge to be pegged? I also c necked the connection of the oil pressure sender to the wire that plugs into the oil pressure sender and my test light does light up

 

saouad

Let me run though this one more time:

Yes this could be the cause but you could also have other issues.

1) For the oil pressure gauge to be pegged it is missing ohms input from the sender. I would go to the oil pressure gauge sender and remove the wire.. ground it out and it should go to 0.. if it does this replace the sender in the engine.

2) For the oil temp gauge.. same test.. only it works in reverse.. A oil temp gauge missing ohms input will go to cool.. (not pegged).. so pull the oil temp wire from the sender and ground it out.. it should go to pegged hot.... If it does this replace the sender.

For everyone.. these gauges will tell you what the issue is if you just get a couple of things in your head.

1) All gauges require power and ground to obtain any movement. No power or ground no movement.

2) Gauges that are missing ohms input will read what we call euphoria.. or the best of what you want. A fuel gauge missing ohms input will give you a full tank of gas, a oil temp gauge missing input will give you a 0 oil temp, a engine temp gauge missing ohms input will give you a cool engine reading.. A oil pressure gauge missing ohms input will give you a high (pegged) oil pressure reading.

So.. just the opposite for a grounding ohms wire.. Each is reversed... you get what you would call the worst reading possible when the ohms wire is grounded...

A fuel gauge will be empty, oil pressure will be zero, engine temp will be pegged hot, and oil temp will be pegged hot..

Food for thought..

Willcox

What your fuel gauge can tell you...



Testing a 68-76 Temperature Gauge -or- What your non working gauge can tell you!

 

1.) ok so all my gauges do move so that means there is power and ground.
2.) looking at my PCB my tabs did lift up from the film i glued them back down and its looks green corrosion along the copper of the entire PCB
3.) grounding the oil pressure sending unit keeps the oil pressure gauge pegged ( already changed sending unit so it is brand new)
4.) oil temp gauge reads 0
5.) fuel gauge reads below empty
6.) volt meter reads 0
7.) two of my light bulbs do not turn on, the connectors are clean and bulbs are brand new
8.) checked the power at each gauge and there is power, tested connectivity for grounds and all checked out
9.) checked the resistor on back of oil pressure gauge and read 35 ohms when installed

here are the pictures of the gauges and how they look when my engine is running
http://s1343.photobucket.com/user/Sh...tml?sort=3&o=3

and of my PCB

http://s1343.photobucket.com/user/Sh...tml?sort=3&o=0

concluding results maybe the printed circuit board? all the senders could not go bad at once could they? the car has been sitting a year but you guys know more than me, I am going crazy here

 

ok so i got my new printed circuit board and all my gauges now function except my oil pressure gauge. it is still pegged and when car is started it goes even further to the right, I tried grounding out the wire like you said and it does nothing for my gauge, still stays pegged. changed the sending unit and checked for power in the wire. I do have power in the wire so what is going on i am lost.

 

Subscribing to this thread, I love troubleshooting!

 

ok so looking at some of the forums I must have the wrong wire. my wire is black and does not have insulation around the wire like was described. I do have a tan wire with a white stripe coming out of the fuse panel area that has white rubber around the wire but does not reach where the sending unit is and doesn't look like it would fit anyways. could anyone post a pick of the wire and where it comes from. it would be much appreciated and thanks in advance. again my car is a 1981.