FireFighterZach Posted January 15, 2013 Report Share Posted January 15, 2013 Hey so now that I have made the 510 my daily driver, I would like to get everything working One problem it has had since I have owned it is the temp gauge has never moved. I added charge to the wire where it plugs in. The gauge went fully up. Replaced the sensor But still nothing. Any ideas? Quote Link to comment
ggzilla Posted January 15, 2013 Report Share Posted January 15, 2013 The sensor does not "add charge". It only provides a ground path (variable resistance). To properly test the gauge, at the engine, disconnect the wire and ground it. Does the gauge move? Quote Link to comment
Laecaon Posted January 15, 2013 Report Share Posted January 15, 2013 Ground should be full hot. Either resistance somewhere in the wire path or voltage divider thing in gauge cluster. But since your fuel works fine, more likely to be a grounding problem... Quote Link to comment
datzenmike Posted January 15, 2013 Report Share Posted January 15, 2013 Yup as said, ground the sender wire to the thermostat housing... the gauge should read full HOT. If not, the wire between the sender and the gauge may be broken or a bad connector. If you can find the Yellow/White stripe wire going into the gauge cluster, ground it and it should go to full HOT. If not, it's in the gauge Quote Link to comment
wayno Posted January 15, 2013 Report Share Posted January 15, 2013 Sometimes the brass senser does not ground good in the aluminum housing, try grounding(cliping) a wire on the neg. battery terminal, and touch the outside of the brass senser housing when the engine is warmed up, if it works, then you have a bad ground in the T housing, and you need to clean the threads that the senser goes into real good, if that doesn't fix it, then the bolts holding the T housing on to the head need to be cleaned. 2 Quote Link to comment
FireFighterZach Posted January 15, 2013 Author Report Share Posted January 15, 2013 Yeah sorry I didn't clarify, I did ground the wire and it read full. Wayno that sound like the problem, the aluminum housing when I took it off had Teflon tape on it so I put some more on it when I replaced the sensor. Ill try taking off the tape tomorrow. Is this tape required? I don't want a slow leak Quote Link to comment
wayno Posted January 15, 2013 Report Share Posted January 15, 2013 The teflon tape could be the problem, and I was not talking about grounding the senser wire, I was saying leave the senser wire on the senser, and with a wire grounded to the battery, ground the outside brass part of the senser with the wire connected to the negative battery terminal, this would simulate the senser grounding out in the T housing, you have to touch the outside of the senser, not the post the wire is connected to, if the engine is warmed up, and you have the key on, it should read normal operating temp. Quote Link to comment
wayno Posted January 15, 2013 Report Share Posted January 15, 2013 See how I have the wire stripped and wrapped around the outside of the senser, and then it goes to a ground bolt, this was the only way I was able to get this senser to ground out without pulling it all apart and starting over, it was supposed to be temporary, it's about 3 years temporary now. :lol: Quote Link to comment
ggzilla Posted January 15, 2013 Report Share Posted January 15, 2013 Teflon tape is not required. Quote Link to comment
MikeRL411 Posted January 15, 2013 Report Share Posted January 15, 2013 Teflon tape is not required. It is a very good electrical insulator! Probably the ultimate cause of your problem. Quote Link to comment
banzai510(hainz) Posted January 15, 2013 Report Share Posted January 15, 2013 Wayno thats a good trick. I have never had proplems with Telfon tape as I figure it would cut the the edges any way and I just put it on the more at the far end where the hex nut would be. . the 1st 25% would still be the brass sender threads Quote Link to comment
ggzilla Posted January 15, 2013 Report Share Posted January 15, 2013 Why do you put Teflon tape on? Quote Link to comment
datzenmike Posted January 16, 2013 Report Share Posted January 16, 2013 To keep from seizing/leaking, but any anti seize compound would work better. Quote Link to comment
datsunaholic Posted January 16, 2013 Report Share Posted January 16, 2013 Teflon tape isn't supposed to be a leak preventative. It's to allow the threads to turn freely, allowing a tighter connection than without so that the PIPE WRENCH doesn't slip. (My grandfather was a pipefitter, and we replumbed my house. I learned a lot.) The reason Wayno (and others) may need a "ground strap" is because they managed to get a perfect insulator via the gaskets. The block with the sensor in it has no physical metal-to-metal connection, since it's sandwiched between 2 gaskets due to the Roadster thermo housing design. L-series have a direct bolt connection, but it has to be perfectly clean, and adding anti-sieze can make the connections poor. Plus I've seen so many that are simply plastered in RTV, which is a type of rubber, and also a very good insulator. 1 Quote Link to comment
FireFighterZach Posted January 16, 2013 Author Report Share Posted January 16, 2013 Why do you put Teflon tape on?It was on it when I took it off, so I assumed it was nessesary I took it apart again. Removed the Teflon tape, clean it with steel wool, put that electrical grease to make sure I get a good contact and it worked for a second but it stopped. I shoved a test light in the female part of the wire with the other end on the positive terminal and the light flashed? The male side on the sender was a constent ground. I'm gonna scrub the female end in the hopes that it is my loose end Quote Link to comment
Laecaon Posted January 16, 2013 Report Share Posted January 16, 2013 Take a random wire. Loop it around the sender, and then to any bare metal other than the thermostat housing. See if that works. We are saying either the sensor is isolated from the housing, or the housing is isolated from the head. Quote Link to comment
FireFighterZach Posted January 16, 2013 Author Report Share Posted January 16, 2013 The sender is giving off a ground charge. Quote Link to comment
ggzilla Posted January 16, 2013 Report Share Posted January 16, 2013 > The sender is giving off a ground charge. What are you trying to say? I've never heard a statement like that. Quote Link to comment
Laecaon Posted January 16, 2013 Report Share Posted January 16, 2013 Me either. You mean you hooked up your multimeter and checked for resistance between the sensor and the negative battery post and got like .05 ohms? Quote Link to comment
wayno Posted January 16, 2013 Report Share Posted January 16, 2013 The male part of the sender/senser means nothing when the engine is cold, as it is not making any kind of connection when cold, it only starts doing anything when warmed up. What's important here is that the senser has a good ground, if it does not have a good ground, it is not going to work. Putting 12 volts into the wire going to the gauge/light will do nothing, as it is 12 volts, or whatever the gauge voltage regulator puts out, the senser is what makes the connection to ground, if you stick a small screwdriver into the end of the senser wire/plug and ground it, the temp gauge should go to hot/overheated, if your gauge works(shows hot when grounded out), then the senser is bad, or it is not grounding in the thermostat housing, or the housing is not grounding out to the head. I posted a photo above showing a copper wire wrapped around the outside of the senser going to the thermostat housing stud/bolt, this grounded out the senser, and now it works. Have you tried a wire or alligator clip to ground out the outside part of the senser like in the photo I posted above? Quote Link to comment
FireFighterZach Posted January 22, 2013 Author Report Share Posted January 22, 2013 BAHAHAHA! i figured to out today. here is the story So i was browsing the Ratsun facebook page and someone posted that they changed there theromsat so the car would heat up faster than 20 mins, and then it hit me, what if my thermostat is stuck open and the coolant isnt getting the time to get warmed up? so i bought a new thermostat and gasket ($9.20) and while taking the cover off a bolt snapped. YAY! but what did i find when i took the cover all the way off? NOTHING! there was no thermostat in the car WTF!?!?!. so long story short i popped the new one in and BAM the heater blows hot air and the temp gauge works! RESOLVED! thanks you guys for the advice! Quote Link to comment
ggzilla Posted January 22, 2013 Report Share Posted January 22, 2013 Good on ya! Another Datsun fixed by restoring it to stock specification. 1 Quote Link to comment
banzai510(hainz) Posted January 22, 2013 Report Share Posted January 22, 2013 Just monitor the temp . As they took the stat out for a reason. Even with no stat in ther you should have got soem kind of reading esp in the summer time Quote Link to comment
FireFighterZach Posted January 22, 2013 Author Report Share Posted January 22, 2013 Yeah I was worried about that when I was working on it, I'm taking her on a 3 hour road trip this weekend so it will be put to the test. Quote Link to comment
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