Electric Gauge Issue?

[BamaTJ]

Hey guys, I am scratching my head over here. I have 3 electric gauges, volt meter, trans temp and oil pressure. I have 12v power from the ign swtich and a ground from my ground block going to the voltage meter and the other two gauges daisy chain the power and ground off of it. Well when I hit the ign the volt meter works fine, the other just peg out as far as the needle will go. I have not actually run it yet since installing them, should I do that or does it matter? Any ideas or suggestions would be great, I can't put the panels back on until I fix this issue

 

[87yjtoy]

Matt, are the sending units installed? If they are then there is a short in the wiring, or the sending units themselves are not working properly.
The sending units go to ground to tell the gage where to be.

 

[BamaTJ]

Yeah they are autometer gauges, 3 wire hookup on the back not including the light. There is a Terminal for the Sender (S), Terminal for 12v Power (IGN) and Terminal for Ground (G). So I have all those hooked up as marked and as all the gauges should be. These are the same gauges I have always had and they have worked fine till the re-wire...

 

[caglezxj]

Sounds like something is getting more power to the S side... Like a short would do. Undo 1 of the gauges and see if the problem goes away. I had 2 wires for the light, 1 for ign, 1 for ground and 1 for sender. The 2 for the light I ran to my lighting terminal 1 ground 1 12v lighting source. The Ignition comes from ignition power, Then 1 from the sender, Then 1 for ground. Let us know what you find.

Are you sure you got a good ground?

 

[BamaTJ]

Well I had the issue with the oil pressure gauge, so I was thinking sender was bad. I added a trans temp gauge today and daisy chained it in with the rest of the gauges and now it has the same issue. So I am pretty sure that both senders have not failed. I need to check the grounds and start there.

 

[caglezxj]

Yeah with 2 of them doing it it has to be something causing it. Is your engine running on rubber isolators or is it solid mounted? If on isalators make sure your engine is grounded good.

 

[BamaTJ]

Just went and troubleshooted, I can remove the Ground wires at the back of both gauges and I still get the same thing, maxed out temp and pressure gauges, If I pull the ground for the Voltmeter it dies. So I tried to ground the other two gauges directly to the ground strap going to the motor, same issue. I then tried to ground the both senders with a 2nd wire in case they were not grounding through the threads, same issue. Any ideas?

 

[Juan_Hong_Loe]

Is the ground block you are talking about on the panel we just sprayed? If so check to make sure the engine is actually grounded. That panel being sprayed might have something to do with all of this.

 

[BamaTJ]

Is the ground block you are talking about on the panel we just sprayed? If so check to make sure the engine is actually grounded. That panel being sprayed might have something to do with all of this.

No, nothing is grounded to that panel you sprayed. I tried grounding directly to the engine ground strap which runs from the engine to a tab and 1/4" bolt that the firewall mounts too. This is my main ground and all things grounded there work fine...

I guess after troubleshooting the ground the only source left is the senders. It just seems very odd to me that two of them are bad, since they worked fine before..

 

[87yjtoy]

Yep sounds like ground issues. It should not die when you pull the gnd on the volt meter. I have all 5 of my gages wired that way. Look at the back of Seebass's panels. Same way.

 

[John Galbreath Jr.]

Make a jumper wire and take the ground direct to the battery. Disconnect the two gauges, so you can work on them one at a time. I doubt two senders have failed.

 

[caglezxj]

I guess you have a meter, if so you can turn it to "continuity check" ,the one with the curved lines , normally beside the ohms. You can then check to see if you have continuity between your firewall and engine block...You can do this reading OHM's also but the continuity check is easier for most, some meters have the audible beep as well.

Are you sure you had the Voltmeter wired correctly? It wires a little different than the other 2 meters. And by pulling the wire off of it and the other meters dropping back to zero could be the issue here. Double check the Voltmeter wiring... If I remember correctly on my voltmeter you just wire ign +ground then the 2 light wires. But I have slept since then...

 

[BamaTJ]

I just re-wired the tranny temp gauge to make the Sender wire go to the ground on the back of the gauge, and then ign 12v to the IGN terminal. It moves the needle a lil bit when it gets power,but it does not max out. but then again the vehicle is not running. If I try to hook up the ground to anything at all the gauge maxes out.

I messed with the oil pressure and tried to wire it the same as I did with the temp gauge, nothing, needle does not move at all. Anytime I try to use the sender terminal it maxes the gauge out. I read in the instructions that you can damage the sender by putting the ign pwr to the sender wire on the back of the gauge, I am positive I did that and gave it power to test. I am going to call autometer, and I may just buy a new oil pressure sender if I can find one local to test out

 

[BamaTJ]

Dude fawk AutoMeter, I called today trying to get some technical support from them and got take the gauges off and send them to us? Really because that is a solution that really helps me. Didn't even attempt to help me troubleshoot the issue.

I really have no clue what else to test for. I take the power and ground to the battery via jumper wires and the sender still pegs to max? That means bad sender, or at least that is all I can come up with. Sender for oil pressure is almost as much as the gauge.

 

[s10me]

Matt, do you know any one local to you that works at a electrical shop? if so see if you can borrow a rheostat to test the sensor circuit of the gauge. you can hook it to ground and the other end the gauge you can ajust it to see if th gauge moves correctly.

 

[s10me]

if you can't find a rheostat find a 0 to 90 ohm fuel sender and use it

 

[BamaTJ]

I don't know anyone off hand. I have tried to find some senders to buy locally and see if they fix the issue. If not I can always take them back, no luck with any parts stores or race shops.

Jamie and I talked about it this morning and for the oil pressure gauge I know we swapped the wires on the S and I hookups because it is backwards from all the other gauges. He was thinking since we maxed the sender out with 12v, I may need to actually fire the engine and see if it changes or can reset itself know that it is hooked up correctly.

 

[s10me]

if you sent 12volts to it its probably trashed.

 

[BamaTJ]

Yeah I think I am going to get a manual oil pressure gauge and a new temp sensor for the trans. The new oil sender is $20 less than a mechanical gauge and it will be less of a PITA I believe. I have troubleshot everything, short of putting a meter on the sender. I have given in a direct power and ground from the battery, engine, etc., everytime I try and connect the sender terminal it goes to max.

 

[87yjtoy]

Matt, all the sender does is regulate the amount of ground that is getting to the gage. If you sent 12v to it = toast. if you get no gage reading with the gage wired up G to ground I to power S to sender. that is correct because the oils are cold. hot fluids should get a reading but if they dont, take the sender wire off the sender & touch that wire to a ground (not 12v) then gage should max out. if it doesn't ,bad gage also. if it does max out , bad sender.