1998 Ranger 2.5L Temp. Gauge issues
Thread Starter
|
Member
Joined: Sep 2019
Posts: 2
Likes: 0
From: Radcliff, Kentucky
1998 Ranger 2.5L Temp. Gauge issues
I’ve been having temp. gauge issues for a while now. At first it was my thermostat in the housing and when I replaced it, it was fine. Later down the line, the gauge dropped again. I thought it was my thermostat again so I replaced it, not fix. So I went to find a ECT sensor for the housing and the auto stores (Advanced Auto and Autozone) had to really dig into their systems to even find the one I pulled out of my housing. The tip that goes into the housing looked like a tube shape where as the one they tried to sell me at first was like a cone shape. I told them this isnt what I pulled out of my truck and then we continued to search until we found one that had a matching end. Went home, put thread tape on the threads and put it in. Gauge read fine for the first ride and then later in the day it dropped again to the bottom. Should I try the sender next? Could it be the wiring? I’m just at a loss on what to do.
Welcome to the forum
Test the wiring by GROUNDING the red/white wire that's on the sender, turn on the key and if the wire is grounded gauge should go to above HOT
Remove the ground wire and it should go down to COLD repeat as you see fit
This test can show the reverse on some Ford models but either way you should get FULL range, COLD to HOT, if not then there is a problem with wire or gauge
Important question.................does the sender have TWO wires or ONE wire
If sender just has ONE wire then the tape you put on the threads is preventing a good GROUND so you need to pull out the sender and leave a few bare metal threads at the bottom and reinstall, it needs a good ground to work correctly
If sender has TWO wires then test the "other wire" for a good ground, if that wire doesn't have a good ground then sender won't send correct temp to the gauge
You were correct, sender is a 12volt device and has a cylinder shape at the end that goes into the engine/coolant
ECT sensor is a 5volt device and has a cone shaped end, so not at all interchangeable, sensor is always TWO wires and only used by the computer
Test the wiring by GROUNDING the red/white wire that's on the sender, turn on the key and if the wire is grounded gauge should go to above HOT
Remove the ground wire and it should go down to COLD repeat as you see fit
This test can show the reverse on some Ford models but either way you should get FULL range, COLD to HOT, if not then there is a problem with wire or gauge
Important question.................does the sender have TWO wires or ONE wire
If sender just has ONE wire then the tape you put on the threads is preventing a good GROUND so you need to pull out the sender and leave a few bare metal threads at the bottom and reinstall, it needs a good ground to work correctly
If sender has TWO wires then test the "other wire" for a good ground, if that wire doesn't have a good ground then sender won't send correct temp to the gauge
You were correct, sender is a 12volt device and has a cylinder shape at the end that goes into the engine/coolant
ECT sensor is a 5volt device and has a cone shaped end, so not at all interchangeable, sensor is always TWO wires and only used by the computer
Thread Starter
|
Member
Joined: Sep 2019
Posts: 2
Likes: 0
From: Radcliff, Kentucky
Welcome to the forum
Test the wiring by GROUNDING the red/white wire that's on the sender, turn on the key and if the wire is grounded gauge should go to above HOT
Remove the ground wire and it should go down to COLD repeat as you see fit
This test can show the reverse on some Ford models but either way you should get FULL range, COLD to HOT, if not then there is a problem with wire or gauge
Important question.................does the sender have TWO wires or ONE wire
If sender just has ONE wire then the tape you put on the threads is preventing a good GROUND so you need to pull out the sender and leave a few bare metal threads at the bottom and reinstall, it needs a good ground to work correctly
If sender has TWO wires then test the "other wire" for a good ground, if that wire doesn't have a good ground then sender won't send correct temp to the gauge
You were correct, sender is a 12volt device and has a cylinder shape at the end that goes into the engine/coolant
ECT sensor is a 5volt device and has a cone shaped end, so not at all interchangeable, sensor is always TWO wires and only used by the computer
Test the wiring by GROUNDING the red/white wire that's on the sender, turn on the key and if the wire is grounded gauge should go to above HOT
Remove the ground wire and it should go down to COLD repeat as you see fit
This test can show the reverse on some Ford models but either way you should get FULL range, COLD to HOT, if not then there is a problem with wire or gauge
Important question.................does the sender have TWO wires or ONE wire
If sender just has ONE wire then the tape you put on the threads is preventing a good GROUND so you need to pull out the sender and leave a few bare metal threads at the bottom and reinstall, it needs a good ground to work correctly
If sender has TWO wires then test the "other wire" for a good ground, if that wire doesn't have a good ground then sender won't send correct temp to the gauge
You were correct, sender is a 12volt device and has a cylinder shape at the end that goes into the engine/coolant
ECT sensor is a 5volt device and has a cone shaped end, so not at all interchangeable, sensor is always TWO wires and only used by the computer
The front is what I replaced and has the cylinder end, but I haven’t touched the rear one yet.
Speaking of the thread tape, I may have covered too much with it like you said, my rear one doesnt appear to have tape at all and just the stock red threading stuff. But if it were interfering wouldn’t it not read at all? Like I said it read fine and later in the day hot the bottom again.
It looks like your sender has TWO wires so the tape is fine, the threads are not used as a Ground, but test the black/white ground wire for a good connection to ground
i.e. pull off connector and put a jumper between both wires, turn key on, should show HOT
No, no reason to start the engine for this test
ECT sensor has the green/red, grey/red wires
i.e. pull off connector and put a jumper between both wires, turn key on, should show HOT
No, no reason to start the engine for this test
ECT sensor has the green/red, grey/red wires
Member
Joined: Sep 2021
Posts: 3
Likes: 0
From: Gladstone, OR
I'm having this same issue. Temp gauge not working correctly. Replaced thermostat, thermo housing (Motocraft, that came with new temp gauge and ECT sensors) and gauge still doesn't work. Gauge is good by test in this thread of putting a jumper between both wires (temp gauge went up to max hot). Ground is good to temp sensor connector too (tested with multi meter). Heater blows warm/hot air. What else could it be?
If the red/white wire tests as OK, then problem is the sender
Should be a red/white and a black/white wire on the temp sender, when these 2 wire are disconnected from sender and then jumpered together when key is turns on temp gauge should go to HOT
That means BOTH wires are OK, and you need to replace Sender, new or not
If gauge doesn't go to hot then they are not OK and its a wiring issue, need to pull the dash most likely
Its NOT a sensor
There is a 5volt ECT sensor, has a grey/red wire, that's just for the computer
Temp sender uses 12volts, looks similar but just on the outside, inside is way different
Should be a red/white and a black/white wire on the temp sender, when these 2 wire are disconnected from sender and then jumpered together when key is turns on temp gauge should go to HOT
That means BOTH wires are OK, and you need to replace Sender, new or not
If gauge doesn't go to hot then they are not OK and its a wiring issue, need to pull the dash most likely
Its NOT a sensor
There is a 5volt ECT sensor, has a grey/red wire, that's just for the computer
Temp sender uses 12volts, looks similar but just on the outside, inside is way different
Member
Joined: Sep 2021
Posts: 3
Likes: 0
From: Gladstone, OR
.
I have tried two new senders now. One Motocraft and one not. Temp gauge goes all the way to hot when using a jumper on the gauge sender connector, so gauge is good. Temp gauge still doesn't work correctly
If the red/white wire tests as OK, then problem is the sender
Should be a red/white and a black/white wire on the temp sender, when these 2 wire are disconnected from sender and then jumpered together when key is turns on temp gauge should go to HOT
That means BOTH wires are OK, and you need to replace Sender, new or not
If gauge doesn't go to hot then they are not OK and its a wiring issue, need to pull the dash most likely
Its NOT a sensor
There is a 5volt ECT sensor, has a grey/red wire, that's just for the computer
Temp sender uses 12volts, looks similar but just on the outside, inside is way different
Should be a red/white and a black/white wire on the temp sender, when these 2 wire are disconnected from sender and then jumpered together when key is turns on temp gauge should go to HOT
That means BOTH wires are OK, and you need to replace Sender, new or not
If gauge doesn't go to hot then they are not OK and its a wiring issue, need to pull the dash most likely
Its NOT a sensor
There is a 5volt ECT sensor, has a grey/red wire, that's just for the computer
Temp sender uses 12volts, looks similar but just on the outside, inside is way different
If its a 2 wire sender are you using the Black/white wire as the ground for jumper wire, have to do that, sender needs a good ground to work
If 1 wire sender then threads must be bare metal to ground the sender to engine metal
Have seen some senders mounted to heater hoses, so no ground, have to use 2 wire sender and ground it, or ground the metal "Bung" on the rubber hoses that sender screws into
If 1 wire sender then threads must be bare metal to ground the sender to engine metal
Have seen some senders mounted to heater hoses, so no ground, have to use 2 wire sender and ground it, or ground the metal "Bung" on the rubber hoses that sender screws into
Member
Joined: Sep 2021
Posts: 3
Likes: 0
From: Gladstone, OR
If its a 2 wire sender are you using the Black/white wire as the ground for jumper wire, have to do that, sender needs a good ground to work
If 1 wire sender then threads must be bare metal to ground the sender to engine metal
Have seen some senders mounted to heater hoses, so no ground, have to use 2 wire sender and ground it, or ground the metal "Bung" on the rubber hoses that sender screws into
If 1 wire sender then threads must be bare metal to ground the sender to engine metal
Have seen some senders mounted to heater hoses, so no ground, have to use 2 wire sender and ground it, or ground the metal "Bung" on the rubber hoses that sender screws into
Then not sure what the problem would be
Temp Sender will have a cylinder tip, the end that's in the coolant, like this: https://m.media-amazon.com/images/I/..._AC_SY355_.jpg
ECT sensor will have a Cone tip, like this: https://i.ebayimg.com/images/g/OPcAA...ORD/s-l300.jpg
Temp Sender will have a cylinder tip, the end that's in the coolant, like this: https://m.media-amazon.com/images/I/..._AC_SY355_.jpg
ECT sensor will have a Cone tip, like this: https://i.ebayimg.com/images/g/OPcAA...ORD/s-l300.jpg
Welcome to the forum
There is no heater valve, there is a by-pass valve, it has a Grey Vacuum hose on it that runs to the firewall on passenger side, NOT TO THE ENGINE vacuum, just unhook it if in doubt
There are several reasons for no heat in the cab
Start engine or drive it for more than 10 min, then shut it off
Open the hood and feel the heater hoses at the firewall, BOTH should be hot
If neither is hot, feel them on the other side of by-pass valve, if both are hot then by-pass valve has vacuum all the time, unhook the vacuum hose
If only 1 is hot then heater core is clogged up, need to flush it out or replace it
If both are hot then Blend Door in the cab is not working
Google: Ford Ranger Blend Door
Common issue for no heat in the cab
Temp sensor and temp sender(they are different), only report heat they don't control it
If dash temp gauge works, comes up a bit, then its working, if it doesn't go up above 1/3 after 10min drive then thermostat could be stuck open, heater would still get warm(120deg) but not HOT(190deg)
There is no heater valve, there is a by-pass valve, it has a Grey Vacuum hose on it that runs to the firewall on passenger side, NOT TO THE ENGINE vacuum, just unhook it if in doubt
There are several reasons for no heat in the cab
Start engine or drive it for more than 10 min, then shut it off
Open the hood and feel the heater hoses at the firewall, BOTH should be hot
If neither is hot, feel them on the other side of by-pass valve, if both are hot then by-pass valve has vacuum all the time, unhook the vacuum hose
If only 1 is hot then heater core is clogged up, need to flush it out or replace it
If both are hot then Blend Door in the cab is not working
Google: Ford Ranger Blend Door
Common issue for no heat in the cab
Temp sensor and temp sender(they are different), only report heat they don't control it
If dash temp gauge works, comes up a bit, then its working, if it doesn't go up above 1/3 after 10min drive then thermostat could be stuck open, heater would still get warm(120deg) but not HOT(190deg)
Last edited by RonD; Oct 29, 2021 at 12:49 PM.
Thread
Thread Starter
Forum
Replies
Last Post
