coolant temp sensor location?

M Body General Discussion

  1. IndieDippy

    IndieDippy Well-Known Member

    Messages:
    183
    Likes Received:
    41
    Joined:
    Jul 22, 2017
    Location:
    Baltimore
    so my cars temp gauge has never worked (88 Gran Fury non AC) and the alternator gauge only occasionally springs to life on start up before dying seconds later. beginning to think it might need a new coolant temp sensor to fix this. car sometimes stalls during summer and can be slow to warm up in winter. as i daily the car this can be a big problem. anyone knows where its located and if it'll be a big mess to change that'd be a great help. i'm hoping i won't have to clean up a bunch of coolant during this
     
  2. Duke5A

    Duke5A Well-Known Member

    Messages:
    945
    Likes Received:
    398
    Joined:
    Apr 6, 2018
    Location:
    Michigan
    It's located in the front of the intake manifold with one wire going to it. Can't miss it. To test the gauge take the wire and ground it somewhere. The gauge should go all the way over to hot.
     
  3. Demonracer

    Demonracer Active Member

    Messages:
    29
    Likes Received:
    7
    Joined:
    Apr 6, 2012
    Do all of the other gauges work? If not, try checking the IVR, if it has one. The temp sensor should be located on the front of the intake, close to the thermostat housing. If you have a service manual, it should show you where it is & what it looks like.
     
  4. Mikes5thAve

    Mikes5thAve Well-Known Member

    Messages:
    415
    Likes Received:
    130
    Joined:
    Mar 3, 2020
    Location:
    Canada
    If you replace it make sure the length of the new one matches what comes out. When I replaced mine years ago I tried 2 or 3 that didn't work right before using one from an old intake I had kicking around.
     
  5. LSM360

    LSM360 Well-Known Member

    Messages:
    347
    Likes Received:
    75
    Joined:
    Nov 28, 2011
    Location:
    Melbourne, Florida
    You can very easily see it on my truck intake right up front

    PW360.jpg
     
    SuicideRider likes this.
  6. Sub03

    Sub03 Active Member

    Messages:
    36
    Likes Received:
    20
    Joined:
    Apr 5, 2020
    Location:
    Norway
    It's quite normal for the alternator gauge to tip a little to the right after startup before settling in the middle position after a few seconds. The middle position is normal, a little to the right meaning the alternator is charging the battery and a little to the left meaning the battery is being drained. I think you can test it by turning on the headlights and maybe some other electrical load, and with ignition on you should se the needle leaning a bit to the left position.

    If the coolant level in your radiator is lower than your intake it won't cause a mess when loosening the temp sensor.
     
    Last edited: Dec 13, 2020
  7. LSM360

    LSM360 Well-Known Member

    Messages:
    347
    Likes Received:
    75
    Joined:
    Nov 28, 2011
    Location:
    Melbourne, Florida
    Alt gauges tend to be pretty useless on these cars and not move at all or not much.
     
  8. Sub03

    Sub03 Active Member

    Messages:
    36
    Likes Received:
    20
    Joined:
    Apr 5, 2020
    Location:
    Norway
    I totally agree. That's why I wrote "tip a little to the right" to explain to IndieDippy that his alt gauge may be working after all.

    Maybe a voltmeter would have been better, but I kind of like the Mopar old style alt-meter.
     
    MoparDan and LSM360 like this.
  9. Mikes5thAve

    Mikes5thAve Well-Known Member

    Messages:
    415
    Likes Received:
    130
    Joined:
    Mar 3, 2020
    Location:
    Canada
    Of those 2 guages the temp one is the only one I've ever had move and once warmed up it stays out. Which is a good thing because at least you know both gauge and cooling system work. The alt one you'd need a microscope to see the difference.
     
  10. MoparDan

    MoparDan Well-Known Member

    Messages:
    366
    Likes Received:
    53
    Joined:
    Mar 17, 2011
    Location:
    Daytona Beach, FL
    Since both gauges don't work right check the metal tabs that the gauges plug into, mine had the opposite happening: the temp gauge sometimes worked and the alternator gauge didn't work at all, it turned out the tabs weren't tight enough and not making contact, I took the tabs off, bent them tighter with pliers, put them back in, plugged the gauges back in and they've both worked great since
     
  11. LSM360

    LSM360 Well-Known Member

    Messages:
    347
    Likes Received:
    75
    Joined:
    Nov 28, 2011
    Location:
    Melbourne, Florida
    Same here. Temp gauge works properly. But I like the look of stock gauges same as sub03 so I keep things as they are. I swear, the slightest change in dash lights and I can tell now lol. That's my indicator my alternator is getting weak.
     
    Sub03 likes this.
  12. IndieDippy

    IndieDippy Well-Known Member

    Messages:
    183
    Likes Received:
    41
    Joined:
    Jul 22, 2017
    Location:
    Baltimore
    oh how i hate taking the dash off. shifter is in the way.
    i took it off to fix my heat awhile ago and only succeeded in breaking my radio. i guess if i must. anyway i found the temp sensor. i'll check both. the wires and area around the temp sensor are covered in muck so i wouldn't surprise me if its broken.
     
  13. IndieDippy

    IndieDippy Well-Known Member

    Messages:
    183
    Likes Received:
    41
    Joined:
    Jul 22, 2017
    Location:
    Baltimore
    so i took off the dash and made sure those were plugged in. this amounted in the Alternator gauge moving slightly and the coolant gauge flashing a red light before doing nothing. oh and me breaking half of the dashboard screw clips ‍
     
  14. JLN5thAve

    JLN5thAve Well-Known Member

    Messages:
    79
    Likes Received:
    29
    Joined:
    Mar 13, 2018
    Location:
    New Mexico, USA
    Been There!! Most of the clips break as they are just so old - I found that the screws hold the dash panel in nice enough without much concern. As to the gauges -

    Sounds like the sensor itself might be in need of replacement. I havent ran into that problem on The Pearl yet - only have the issue with my fuel gauge being dead as a door-nail. Alt gauge sounds like it is working right. Dont quote me tho -

    Taking that dash off sucks - but the nice thing is, with the e-brake on (assuming it works) you can drop the shifter into 1st and slide it right off. Unfortunate about your radio - stock ones are tricky to find depending on where you are, or if you seek them online kinda pricey. I ended up with an aftermarket.
     
  15. IndieDippy

    IndieDippy Well-Known Member

    Messages:
    183
    Likes Received:
    41
    Joined:
    Jul 22, 2017
    Location:
    Baltimore
    year replaced my radio with one from a 90s jeep. sadly its tape deck doesn't work as i liked listening to old cassettes. not sure about my E-Brake as i once or twice drove all over town with it down. for now the Dash is still hanging down just a little. will wait till it gets warmer to fix and also to find a temp sensor. for now the car works well after waiting a good while for it to warm up
     
    MoparDan likes this.
  16. 69-

    69- Active Member

    Messages:
    33
    Likes Received:
    24
    Joined:
    Dec 13, 2020
    Location:
    Germany
    All gauges work properly here. With the clips you really need to be careful, better doing it in a warm environment, such as the usual kitchen table. Wife not happy, but it works. :cool:

    Will exchange radio shortly to a retrosound 1.5 DIN.
     
  17. IndieDippy

    IndieDippy Well-Known Member

    Messages:
    183
    Likes Received:
    41
    Joined:
    Jul 22, 2017
    Location:
    Baltimore
    newyorkface_933a7448-0dfc-4d98-9e88-792053aee0f1.jpg
    ooooo i like. fits right into the Diplomat? plug right in to need wire work? also do you know where i can get new Dash clips? what are they called?
     
  18. Mikes5thAve

    Mikes5thAve Well-Known Member

    Messages:
    415
    Likes Received:
    130
    Joined:
    Mar 3, 2020
    Location:
    Canada
    Dash clips? You mean what the screws go into?
     
  19. IndieDippy

    IndieDippy Well-Known Member

    Messages:
    183
    Likes Received:
    41
    Joined:
    Jul 22, 2017
    Location:
    Baltimore
    yes
     
  20. 69-

    69- Active Member

    Messages:
    33
    Likes Received:
    24
    Joined:
    Dec 13, 2020
    Location:
    Germany
    I meant the clips holding the sub-assembly of e.g. the ammeter, coolant-gauge and two or three warning lights.

    With those holding the screws you can just be careful while tightening. Sometimes you're just unlucky and they're "done". Maybe a dot or two of super-glue might help to revive them (let it dry first and then screw the screw in).