its been a while since i been tgo, the search doesnt seem to work like it used to, everytime i search for stuff it goes to google or doesnt bring back anything near what i searched for..
anyway, can someone tell me how to test the gauges either when they re in the cluster or pulled out?? i have a 90ohm resistor, clips and power supply.
sometimes the battery gauge is full or low, never in the middle around 13-14v, the oil pressure gauge always read high and the fuel gauge is always full even with half tank..
thanks

 

What vehicle and year? Kind of sounds like a bad ground for the gauge pod.

 

1985 iroc-z

 

the gauge lights work..

 

i just checked and the tach doesnt work well either...
can we post videos here??

 

I don't have a schematic for that one. But if there's a high resistance ground then voltage will read low, oil pressure will read high, and fuel gauge will read high. Not sure about Camaro but on the Firebird the grounds are connected to the metal dash support rail right next to the steering column.

 

i have the service manual and it says to test with a j-24538-a (basically a 90 test meter)
i have a 90 ohm resistor, so i wanna test each gauge separately if the ground turns out to be good...

 

If you have a real GM service manual then you have the best step by step guide that exists. There should be a troubleshooting procedure in there for each gauge.

 

it does but it i also need a way to test them separately outside the gauge cluster..
do i hook up a power supply with the 90 ohm in series? or use a variable resistor in series with the gauge and see if it moves??

 

Last time I played with a fuel gauge I hooked up a 9-volt battery and a spare level sender and moved the sender through its range. Variable resistor will work if you have one.

The gauge is damped and takes a while to move.

 

thanks again,

but whats up with the tgo search tool?? it used to bring up tons of stuff, now like 2 results completely different from what i asked...

 

I have no problem with the search. Use the "Search" in the blue bar instead of the one at the top of the page. Click advanced

 

rigged up a tester for the gauges and they test fine so i have to pull out cluster and check that.
got a 9v battery, 1k potentiometer in parallel with a 90 ohm resistor and switch. connected one screw to the pos side, one side to ground and third screw to resistor then to ground.
when i turn on the power and rotate the pot the gauges go up and down smoothly.

 

swapped gauges with my other iroc and same thing, still getting erract twitching and inaccurate readings. sometimes they are at full , then nothing... tach acting wierd too..
any other ideas?
i pulled cluster and made sure the copper is clean , no pinching or cracked plastics

 

You have some grounding issues, that's the only common thing to all the gauges and sensors

 

all the bulbs work, turn signals and check engine/brake indicators work, where else can i check?? the two connectors on the cluster all the correct grounds when i check with test light. could something else be loading down the gauge? is the dimmer switch connected? the bulbs do dim when i turn it, not a smooth dim but it works...

 

The dimmer not smooth is just the carbon film wearing in the dial.

Your ground may have an intermittent problem that won't show up wile you're testing. Also, lights and such would probably still work with a "bad" ground since they are low current. I had an issue where my Dakota Digital GPS speedo would stop working, it was definitely a grounding problem.

In the Firebird the dash ground is on a support for the dash, not the firewall, there can develop rust/resistance between the brace and the firewall. I would assume Camaro is similar/same. Try putting another wire in the ground stack and ground the other end to the firewall/body. It can't hurt even if it isn't the problem

 

replaced ground strap

 

 

cleaned and scraped ground wires on firewall, fender, alt bracket and battery

 

 

the tach still pings to max for no reason and the fuel reads full then half, ill check other gauges when i test drive again and monitor the gauges, only thing left to check is the ground wire going to the back of the cluster on the connectors. can i reach that from up under steering? hate to have to remove the whole thing again...

 

Gauge pod has it's own ground wires as explained earlier. On the Firebird it is accessible after removing the plastic cover under the steering column (2 ring terminals bolted to the metal dash support next to steering column). I don't know exactly where the wires ground on a Camaro.

 

By the way, it could be something as simple as a poor connection at the gauge pod itself. I'm not familiar with the Camaro but the Firebird has a printed green screen on the back of the gauge pod and the electrical connections are just tabs that rub the screen. I've had to clean up those contacts with a pencil eraser.

 

i cleaned the copper grid pads that connector to the left and right connectors, the service manual says there are 3 ground tabs i think.. ill try and run a temporary ground from the cluster directly to the battery and see if that helps...im also going to check up under column like u said...
one more, there is a ground screw on the opposite cylinder head that has a wire connected to it but i cant see where it goes

 

i looked up under dash and can see each connector, nothing lose, real tight up under there.. i did find this one bolt with a black wire connected, i tried to trace it as far i could. ill take it out and clean it and check connection.

 

It looks like somebody has taped the ends and spliced into the ground wire. People don't tape stuff they didn't mess with. I think you found your culprit.

Disconnect the wires from ground and use an Ohmmeter to do a continuity check if those wires go back to the connectors for the gauge pod. If those are the correct wires then I'd dig in and see what's wrong.

 

i cleaned that bolt and put bk, tach still funning acting and ill check other gauges when i pull out car, that bolt and 2 wires connected is for the cluster. ill have to pull cluster back out and run a straight grnd from the spare prong on the cluster thats at the top.

 

yeah, the tape was old and crumbled soon as i took it off. im guessing the bigger wire is for the gauges and not sure what the little wire is for. but ill try and trace it out later..

 

That blue "quick splice" may have cut the wire and now it's just hanging on by a thread. Those splices are terrible when reliability matters.

 

That should be the ground for all the dash stuff. There is rust on the support, which means there could be rust on the joint between that and the firewall. Run another wire with your own connections to that and the FW. Also remove that splice, cut the wire there and put in a new butt joint connector, preferably a non insulated variety and put some nice heat shrink over it

 

ok thanks ill try it and add a ground jumper to that bolt connector. i cleaned the connection point so now onto the f.w location which is tight.

 

changed both wires and connectors, still same results, not sure what else to do. the tach is still maxed out while idle and when car is off and my gas gauge is full.
i saw the temp gauge gradually go up to mid point, the oil pressure also gradually went to normal and the battery gauge is reading about 12.5 volts. im think something between fuel gauge and tank and not sure how to troubleshoot tach...

 

Did you run another wire with them to the FW?

 

ran a wire straight from battery ground to fw bolt and nothing, tach and speedo not working. from researching the boards, i have to drop tank to replace sender which should take care of the fuel gauge. how to check speedo cable? or speedomoter? i have a spare tach i can swap from another cluster but i dont think that will solve my problem.

 

maybe ill pull dash pad off again and run ground wire from battery to back of cluster...

 

There are two ground legs for the fuel gage. One is through the level sender in the fuel tank, other is through a common ground in the gage panel. Look at the schematic in your service manual to figure out which devices use that common ground. If those devices are behaving funky too, then that's a clue.

You're probably better off looking for a common cause for all your problems rather than trying to make each gage work one at a time. Study those gage cluster schematics and look for what's common between all the gages that are misbehaving. (B+ supply side? Ground side? Both?) Heck, you don't even have to study schematics, you can just look at the green screen on the back side of your gage cluster and literally see which devices have common power and common grounds. And remember, the printed screen and little screws in the gage cluster is also part of the electrical circuit so consider those in your troubleshooting.

 

i hate pulling this cluster out but i ll do it again. i trippled checked every ground and used spare gauges, im going to empty the cluster and add gauges and bulbs one at a time, im thinking something else is messing things up.

 

Interesting thread, I also have a 85 IROC, many gauges are functional, but having trouble with temp gauge and fuel. Don’t believe either of them. I can post pictures of my wiring if you need any references. I’m all original so...

 

yes, thnx

 

What do you want me to take a picture of?