• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

b&m trans temp gauge

DurbElites

NAXJA Forum User
Location
Simi Valley
does anyone have this setup on their rig? i just installed one on mine (on the forward line toward the radiator) and at idle the needle jumps all over the place between 0 and whatever temp its at, and when i have my foot on the gas and driving the needle doesn't move at all. i tried getting the air out so i added fluid and filled the t fitting with fluid and ran it for a while driving around town but since startup i cant get the needle to stay put. did anyone else have this problem or what could it be???
 
DurbElites said:
does anyone have this setup on their rig? i just installed one on mine (on the forward line toward the radiator) and at idle the needle jumps all over the place between 0 and whatever temp its at, and when i have my foot on the gas and driving the needle doesn't move at all. i tried getting the air out so i added fluid and filled the t fitting with fluid and ran it for a while driving around town but since startup i cant get the needle to stay put. did anyone else have this problem or wat could it be???

Please explain how you've configured the wiring of your gauge. Specifics are best. Then it's easier for us to help.
 
ok, the install went as follows first i hooked up the ground using the shifter bracket. second i ran the ignition wire to the fuse panel and spliced into the wire that was labeled ign i am assuming ignition. next i spliced into the lights using the lights that are used with the console. and then i ran the sender across the fire wall into the hole thats used for the hood latch and back across the firewall onto the sender which is located on the flat run under the oil filter and its on the forward line. After i connected the t i filled it up with fluid so i would reduce the air in the line and installed the sender then the wire on top with the given connections. started it up checked the fluid and added some, drove around noticed that at idle when i am in drive and reverse it vibrates violently around from current temp to about 110 and back. if i rev the engine up at all or put it in park or neutral its steady. i went home pulled the sender and i noticed also that when i lightly tapped it against the brass t fitting it would jump around and only the brass fitting (?) i say this because when i tapped it against anything else it didnt move just gave the temp. maybe i got a bad sender unit or bad install ( possibly i have idiot days) i followed the instructions and other write ups done on this exact unit so anything else i could try?
 
if the b&m unit is anything like autometers.

make sure that the sending unit is grounded to chassis ground. otherwise it won't work properly.

i found this out when putting in a elec water temp gauge in my last car. i tee'd it into a heater hose line. then noticed it didn't seem to be reading acurately if reading at all. i then ran a ground wire that i attached to the sending unit over to a chassis ground and all was fine.

i suspect the b&m unit is the same with a elec. sending unit.
 
ok i will try that tommorow but i am pretty sure the ground is ok the shifter bracket that its on is zinc coated and clean and mounted to the chassis itself so it got ground but it doesnt hurt to try something else. any other ideas???????
 
Make sure all your connections are good. I'm guessing you used crimp-on style connectors. Just one of them in either the power supply or the ground could mess up the guage. Also, instead of splicing into the wire you mentioned for power, you may want to try just tapping direct into the fuse block through one of the slots labeled IGN or testing any unused slots to find one that's only powered with the key on.

And your rig may not be the same as mine, but in my 95 with an auto, the shifter bracket has a material similar to a gasket between it and the body. So I had to sand the bottom of the head of the bolt that I wanted to use. It is now actually grounding through the bolt where it threads into the floor pan instead of through the bracket.
 
since i have never messed with the fuse panel in this car before can i just get a connection to stick in the panel or place i want or do i have to run a new wire with power from the battery and make a new curcuit? and on my rig there was no gasket just bare metal for the ground but i will move it tommorow and see. also why would the needle bounce when i tapped the sender to the brass fitting and not bounce when it hit anything else?
 
Last edited:
Your connections at the guage could be bad. I'd double check them first.

And to tap into the fuse block, I just use 1/4" male spade style terminals and plug them in in place of where a fuse would go. Since my XJ didn't come with any of the power options (windows, locks, etc.) I have a lot of empty spaces to use. Some of them are always powered, some are only ignition hot. Some of them are labeled with "IGN"(ignition on) or "BAT"(always on) IIRC. On the rest I use a tester (either a voltmeter or one that looks like a screwdriver with a light in the handle). With no key in, I check to see wich open spots don't have power. Then with the key on I check to see which of the ones that didn't have power on before now have power. For such a small power draw like a guage, there's no reason to run a new line from the battery if you've still got open slots in there.
 
really bad connections at the gauge? they are all new and none of the connections are touching each other and the wires are all firmly placed in the connections but i will take another look for $hits and giggles :dunno: .
 
I agree on checking all connections, especially ground.
This is the most common mistake I see when customers come in with similar problems with their 12V accessories.

Grounds should be attaches directly to the sheetmetal, not to a bracket. Even though a bracket may look all nice and shiny doesn't mean it is making a good ground.

Ground it to the Floor, firewall or kickpanel near the gauge.
I usually use a couple star washers, one on top and one on the bottom of the ring treminal. Then I run a self tapping pan head thru them.
This works great, as the star washer on the bottom bites thru the paint into the metal, the top one locks it all down.
The other plus is you don't have a lot of bare metal to worry about rusting or painting. This method has been used in our shop for a long time sucessfully.
 
I've got the same guage on my 96' and it works fine. You really need to check the ground at the sender that is where you will find the problem. I installed my sender in the return line underneath the oil pan. The guage is in a Autometer single guage pod on the "A" pillar. I have a seperate fuse box that I made that has both ignition and battery sources already in it that is located on the drivers side kick panel for easy acsess and easy hookup of accessories. This is where everything "extra" is hooked up in my Jeep, and the fuse/relay box is supplied with a 8 guage wire directly from my Optima and on a 50 amp fuse. Double check the wireing to make sure everything is a solid connection.
 
ok i will go over everything and reinstall again. ALSO A NEW PROBLEM the t fitting is leaking and i tightened the hell out of the entire fitting around the compression fittings the most and it still leaks i used teflon tape so what is a good form of sealant i could use to solve this new problem will that permatex work?
 
I used permatex grey on mine from the start, just a little will do, and no problems in 10k miles. I agree with Tre, you may have overtightned it! You will have to cut the hard lines and put in some new compression rings. I think you will be able to get these at AA, AZ, or a hardware store. Best of luck!
 
For your guage "jumping" issue...
Check to make sure that your sender wire is only touching the threaded sender pole, and is not grounding out to the fittings or the probe body. If it is really close, then vibrations may be making it momentarily ground out.
edit: This is referring to the end that connects to the sender, not the guage.
 
i didnt like crank down with superman arms but they are not loose anyways i will also change the fittings and check the wiring and sender unit for problems i will let you guys know what the outcome is. thanks
 
ok fixed the gauge i guess the connection was touching on the top side that i couldnt see, now i just have to hope that the fitting dont leak but i have to just wait and see tomorrow when its light.
 
Back
Top