I know there are search threads but I was hoping to find an expert to talk to.Fuel Sending Unit is putting out 89 Ohms,I installed new resistor in Fuel gauge,panel is grounded.It read 1/2 tank with nothing on it,put the 12v to it when I cranked the car it went past Full,I think it is ground related.But everything seems to have a good ground. Will it hurt anything other than reading Full ? Any help is apreciated.I am pulling my hair out after installing the Console.
Thanks.........alan

Seems like the needle needs to come off and be "clocked" correctly, or close to it.
Remove the tan wire at the sending unit and install a 45, 48, 0r 50 ohm resistor to ground = 1/2 tank. Or a borrowed resistor decade box from Mr TV repairman.

Seems like the needle needs to come off and be "clocked" correctly, or close to it.
Remove the tan wire at the sending unit and install a 45, 48, 0r 50 ohm resistor to ground = 1/2 tank. Or a borrowed resistor decade box from Mr TV repairman.

Thanks Everett,When above statement said Fuel Sending Unit puts out 89 Ohm's this was before installing in the tank (at simulated Full tank),Update.... I ran a temp. ground jumper from sending unit ground to battery/chassis ground ,no fix. Battery unhooked,I checked ohm's in trunk ,tan to ground gave me 44 ohm's,checked other side of plug-in connector, tan to ground 44 ohm's,Can you help me understand what it means to clock ? Is this resistor temporary to get it to clock ? I am a High Voltage Journeyman Lineman for a power co. but this dc thing sometimes has me scratching my head.Again Thanks for the reply and your help,I really would like to fix this but if I have to tear that console apart 1 more time I might put an aftermarket gauge in the glove box. I really apreciate your help..........take care....alan

Hi 98blackburb,

Is this on a 1st gen or a 98 Camaro (4th gen)?

Did you install a new repro sending unit?

On my 1st Gen, I purchase two bad repro sending units (giving bad readings) that I finally change for a Spectra Premium Sending Unit P/N FG104C (3/8 Single Line) that I purchased from NAPA.

Good Luck, Daniel.

Hopefully, this will help.

http://www.chevelles.com/techref/ftecref18.html

alan

Daniel... Yes 1st. gen,1969 Camaro SS ,It's even Hugger Orange like yours :D Nice car you have there. Console gauges,I too bought a new sending unit (bad), replaced with a new good 89.7 Ohm's before installation. Sad to say but it happened to me from a Well known Camaro place too.I am thinking of taking off Console cover and run a temp. jumper to gauge face and see if it moves it even though panel is grounded,kind of a long shot. Alan ,Thanks for the link ,read that too,Waiting on Everett with this clocking thing. I'm listening if you guys got anything else.......Thanks guys..........alan

I would say with 44 ohms through the sending unit to ground, its telling me you have 1/2 tank of fuel. So gauge should read 1/2 tank.

Tan wire tied to ground, gauge should read empty. Tan wire with a 90 or 100 ohm resistor to ground should read full tank. Of course, all these actions/resistance values connected, with power on, gauge should indicate the cheated level.

In your first post, you said 90 ohms, appiled voltage with key on, and gauge went past FULL. Personally, I found the final FULL indication about three marks past full if gauge was in the cluster. On a console gauge, I would think it would indicate just past F. So I said to clock the gauge, meaning if the needle slams against full rather than rest against F, and if gauge reads something other than alittle more than half (44 ohms), then I would think the needle needs to come off its axis and get pressed back on in the proper spot, mechanically align the needle to the scale to match its electrical input or current flowing.

The gauge has two coils, and the resistance value, 0-90 ohms of the sending unit, determines the amount of current through the coils creating a magnetic field and this field "pulls" the needle weight/axis to indicate on the scale.

I believe console gauges have three posts on it? One for 12V input, one for ground, and one for sending unit. All I have is for a cluster gauge, no console gauge. Your 44 ohms into the harness to the gauge, if I read correctly, should not be there, unless the gauge(?) resistor is there and you're reading it, but still, shouldn't be ohms there to ground. I would really rather not get inside the gauge. I may be too deep into this thinking.

Of course, I too could have too many ohms..............

Everett,you are correct as to my 1st. post,sometimes I get ahead of myself,As far as you having too many ohm's....I doubt that ,I highly respect your opinion and I hold it in high regard, you're a pretty sharp cookie....Good info there Everett ,My Fuel gauge is next to my Oil Pressure Gauge
http://i144.photobucket.com/albums/r185/185sport/consolelights014.jpg?t=1232240331
I believe I have it grounded right,I'm wondering if the Gauge itself is not connecting good enough for the ground,I am going to take off console cover and jumper the gauge metal with a ground to test that theory.Longshot..... Is my resistor in right?
I really apreciate the input and your help,not looking forward to the console apart thing. Real close to running a new gauge in the glovebox hidden .As far as removing and re-clocking,I'm assuming it is a pressed fit.

Before I go any further, I would like to see a schematic of a console gauge set-up. I'll have to check my 68 Assembly manual for one. Might be one inside and I not see it as I was rapid-thumbing through the manual. Any help where these might go? Low level light?

On the resistor, I see a thin green wire and a red(?) thin wire on the other side. But I see a pink(?) wire - power and a tan wire on the plug to the gauge.

To make troubleshooting easier, I would temp place a variable resistor between the ground lug/to dash ground/battery neg post, make it one connection, and the resistor wiper to the tan wire terminal on the gauge. Apply bat power to red/pink terminal gauge and see gauge indication. While varying resistance of resistor from 0-90 ohms, gauge should follow.

Thanks for the vote of confidence - maybe it is a lack of ohms.............let me ask my wife....not!

LOL.........be careful now if Momma ain't happy ain't nobody happy. I told my wife just the other night ....you're right I'm wrong, I'm sorry......she kissed me then I went and ordered more Camaro parts.......yes those small wires are Low Fuel Indicator lights.I am running different console lights each having thier own ground but the cluster is also connected to the gauge panel so all the potential is the same.I bought a 47 ohm resistor today but garage is too cold tonight, 37* in Fla. ,You believe that ? Here is a schematic..............I do have an Automatic......thanks Everett for your help
http://i144.photobucket.com/albums/r185/185sport/scan0003.jpg?t=1232586174
Better view of connections before lights installed,I do have a new resistor in place of old blade style
Hard to see but small black goes to big black,bulb is no longer there, Rick's told me that was for Corvettes for that year
http://i144.photobucket.com/albums/r185/185sport/console.jpg?t=1232586767

I looked at my Assembly Manual and U17-A2 shows the harness hookup to the console gauges. The sketch (didn't have CAD back in "67) does not show a resistor. So it might a gauge thing rather than a harness item.

However, I do remember gauges back in this time frame, both OE and aftermarket, had a voltage dropping resistor, not just for the fuel gauge, but for the others, water temp and oil pressure, as the idea was not to send a full 12V to the sending units, only 5 volts.

A schematic of console gauges woiuld be nice. Maybe some one here will scan one and post it.

If you gauge is new they have the resistor already built into the windings so you don't need the external one. Resistor itself should measure somewhere around 42 ohms (temperature sender resistor measures around 86 ohms) Original ones look just alike, the newer ceramic versions have different color paint daubs on them, pink and blue I think, I don't know which one is which.

Having the wrong resistor (higher resistance) in there (or 2 resistors in series) will make it read beyond full.

When you disconnect the sender at the connector in the trunk and short it to ground (the wire going back to the guage) does the needle go to empty, or stay above full?

Mark , I have'nt got around to it yet, maybe tommorow will be warmer in the garage. Us Fla. boys can't handle the cold....Thanks Mark
Everett I added a schematic up above.Thanks guys for your help........alan

Mark it is an old gauge.............thanks

Thanks for the schematic! Ah-ha! Unplug the gauge and without the low level light, attach the 47 ohm to the tan terminal and the other end of the resistor to ground or negative power source. Attach the pink terminal to 12v power source -gauge should indicate 1/2 tank approximately.

Did you get two 47 ohm resistors? Put them in series, one attached to the other -
lead to res to lead to lead to res to lead = 90 ohms and gauge should read full.
Put them in parallel, 22 ohms, and should indicate 1/4 tank.

The needle is a press fit onto its shaft.

You're welcome.

Guys, I do have a door jam switch out right now also ...going to replace this weekend.Lights in cabin are staying on. Could that effect grounds for the console?

Thanks for the help guys so much, I'll try it soon.

Is the Low Fuel Light changing things ? Thanks Again.........alan

No, door switches provide the ground to light the dome light. Speaking of dome light staying on, have you rotated the headlamp switch knob CCW? The last CW position of h/lamp switch turns on the dome light - dual purpose rheostat adjusts inst cluster brillance and dome light to ON -fully CW.

The resistor for the low level is a set value of resistance so when fuel level is below one gallon, 1/16 full, the light comes on. Yes, the way I see it hooked up, its always in the circuit parallel connected. This resistor value will affect the meter reading when the tank sending unit is connected.

Thanks , yes I've tryed clocking the switch around and it has issues lately. Going to change both while kick panels are off.Can I get by leaving Low Fuel on for now and try the resistor in the trunk to correct gauge value ? Trying to stay away from that console if possible but if I have to I have to.Thanks again so much for your help.......alan

Just unbolt the plug terminals and lift off the resistor with wires and bolt the terminals back on and try the resistor in the trunk. Let me know what happens.

Thanks for the schematic.

Everett ,You're a good teacher. I am learning more on this DC stuff ..will try soon..
Anytime you need a schematic get with me if needed, I bought a
1967-1969 Console gauge & headlight wiring diagram manual. I'll scan it and send it to you.............thanks again.......alan

I found this old one in my photo files, maybe it helps. Ev is a genius with this stuff. :)

http://www.carsbyjim.com/storage/Interior/Consolewiring.jpg

Well guys it is time to Praise Everett ! :D I fought the console tonight
(Console=kinda like a man trying to hang himself with 2' of rope with a 3' knot)
and cut out the Low Fuel Warning Sender Module....better known to me as prick of misery
http://i144.photobucket.com/albums/r185/185sport/LowFuelModule.jpg?t=1232677864
, ended up extending the wires......namely Pink and Tan to where I could finally plug them in. Why does the aftermarket harness have to be so short in the plug areas?:confuse:mad:Thought I'd fire it up and check and :cool:
WAH-LAH.........1/2 Tank on the Fuel Gauge:o.........Just to make sure we were right ,went to the gas station and topped it off and it is about 1 notch under full which is close enough for me.:D:thumbsup::):beers:

Everett ,I can't thank you enough:D


You amaze me because while on one trail fixing that one ....you're like a hounddog on another .....I also tonight replaced both door jam switches because of the interior lights being on...........and you already had mentioned the light switch itself which it turned out to be..............Hey while I have your attention is it hard to change out ?? I have a new one already in the garage .but I am a little intimidated. Is it hard to changeout or fix?
Once Again .........Thank You So Much..............Alan

You're welcome. Isn't this the reason for the forum? To help others?
You sure the present l/switch is bad? Cluster lights flicker due to burn spots on the rheostat and same with dome light - a few quick twisting the bejesus of the knob fixes the problems.

The light switch is easy.
1. Disconnect the battery.
2. Reach up behind the dash and next to the dash/plate, feel for a spring loaded button and press - usually on the same side as connector.
3. Pull out the knob. release button and hold switch body with hand.
4. Remove bezel nut from the front/interior side of dash - unscrews - there is a special spanner srench but I have used a smal pair of needle nose pliers - right hand threads.
5. After nut falls off, unplug harness connector - my OE harness has enough slack I can pull the switch to the bottom of the dash and disconnect - you may have to squeeze the release tab.
6. Plug in new l/switch, connect battery, and try all circuits for proper operation
7. Disconnect the battery, install switch and gently push in knob - no need to press release button.

2. Reach up behind the dash and next to the dash/plate, feel for a spring loaded button and press - usually on the same side as connector.
GM is opposite the wiring connector.
3. Pull out the knob. release button and hold switch body with hand. Pull out knob, push button, remove knob. The button only hits the release tab inside the switch when lights are on.

Jeff

You're welcome. Isn't this the reason for the forum? To help others?
You sure the present l/switch is bad? Cluster lights flicker due to burn spots on the rheostat and same with dome light - a few quick twisting the bejesus of the knob fixes the problems.

The light switch is easy.
1. Disconnect the battery.
2. Reach up behind the dash and next to the dash/plate, feel for a spring loaded button and press - usually on the same side as connector.
3. Pull out the knob. release button and hold switch body with hand.
4. Remove bezel nut from the front/interior side of dash - unscrews - there is a special spanner srench but I have used a smal pair of needle nose pliers - right hand threads.
5. After nut falls off, unplug harness connector - my OE harness has enough slack I can pull the switch to the bottom of the dash and disconnect - you may have to squeeze the release tab.
6. Plug in new l/switch, connect battery, and try all circuits for proper operation
7. Disconnect the battery, install switch and gently push in knob - no need to press release button.

Thanks Everett, You are so much help........thanks again.....let me know if I can ever help you some-how.......alan

You're welcome. Don't forget Jeff's revision to the steps - pull knob to turn on headlamps, then press button, pull knob out. I forgot.

Yea, Buddy..........I'll take those winning Lotto numbers..........only the winning ones, don't give ones you just pulled outta your ........shirt pocket........

Thanks Guys...alan