• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

Coolant guage sits under cold but warms up .

Cypress65

New Member
Joined
Aug 27, 2022
Messages
6
Reaction score
0
Points
1
Location
Md
Vehicle Year
03
Make / Model
Ford ranger
Transmission
Manual
I've recently had my engine swapped and now have my truck back and the only thing I notice is that my coolant gauge sits under C but when the truck warms up its only goes up about a quarter above it. Just curious if this is a issue? Ive just swapped out the thermostat,sender and sensor. With no luck. I grounded the sender wire and it shoots to H. Maybe im just over worrying? Any input would be great.
received_594234962360031.jpeg
 


RonD

Well-Known Member
Joined
Jun 2, 2012
Messages
22,654
Reaction score
5,776
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
Welcome to the forum

2003 Ranger with a 2.3l, 3.0l or 4.0l engine?

If grounding the SENDER wire, red/white wire, gets gauge to go to HOT then that wire is OK
If sender has two wires, a black/white wire, then repeat test but use that 2nd black/white wire as the Ground, because thats what it is, if gauge doesn't go to HOT again then that black/white wire has a bad ground connection

If sender only has 1 wire then Senders threads to the metal of the engine is its Ground, so DO NOT use tape or sealant on the lower threads or you get a weak or no ground and so incorrect gauge reading

If wires test OK then new sender is bad or new thermostat is the wrong one or bad

Rangers all use a 190-195degF thermostat(since the early 1980's), except the 2001, and up, 2.3l which uses a lower radiator hose thermostat rated at 180degF

The gauge is calibrated for 210degF at 1/2 way point, so just below 1/2 would be correct needle position after 5 to 8min of driving time to full warm up
Also check the heater air, it should be HOT after full warm up, 190degF, not Luke warm, if not then its for sure a thermostat issue, not a gauge issue
 
Last edited:

Cypress65

New Member
Joined
Aug 27, 2022
Messages
6
Reaction score
0
Points
1
Location
Md
Vehicle Year
03
Make / Model
Ford ranger
Transmission
Manual
Ok so it blows hot. The sender is only 1 wire.the truck its a 03 3.0 v6. The thermostat that was in there was a 180. I swapped to a 195 or 192 .
 

Cypress65

New Member
Joined
Aug 27, 2022
Messages
6
Reaction score
0
Points
1
Location
Md
Vehicle Year
03
Make / Model
Ford ranger
Transmission
Manual
I have swapped what was in there sender and sensor to Motorcraft parts. I'm assuming all is left is to try to ground it send see if it works right . Appreciate the help!
 

RonD

Well-Known Member
Joined
Jun 2, 2012
Messages
22,654
Reaction score
5,776
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
Sender is 12volt device
Sensor is 5volt device

You can use OHM Meter from sender post to ground with cold engine, 100 ohms or so
And then after warm up, 35 ohms or so
 

Cypress65

New Member
Joined
Aug 27, 2022
Messages
6
Reaction score
0
Points
1
Location
Md
Vehicle Year
03
Make / Model
Ford ranger
Transmission
Manual
I haven't gotten around to test it yet but I think I'm just going go leave it alone it seems to work I suppose.
20220829_102648.jpg
 

RonD

Well-Known Member
Joined
Jun 2, 2012
Messages
22,654
Reaction score
5,776
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
That represents about 185-190degF on the gauge so correct after full warm up, 5 to 8 min of driving
 

Cypress65

New Member
Joined
Aug 27, 2022
Messages
6
Reaction score
0
Points
1
Location
Md
Vehicle Year
03
Make / Model
Ford ranger
Transmission
Manual
Guess I was over worrying about it being past cold in that case. Appreciate the help.
 

BiggSherm1988

Member
U.S. Military - Active
Joined
Feb 1, 2022
Messages
84
Reaction score
48
Points
18
Location
Germany
Vehicle Year
2008
Make / Model
Ford/Ranger
Transmission
Manual
Total Lift
none...yet
Total Drop
not for me
So mine sits at this level but occasionally on a cold day I will get a fault that says "P0128 Coolant thermostat- coolant temperature below thermostat regulating temperature." I have never figured it out but all summer I didn't have it pop up. now that its fall I have started to get it popping up on cold days.

I haven't tried grounding the temp sender though. It definitely blows HOT air too. I kinda thought maybe its because its freaken cold here in Germany and its just cooling down the coolant too much. I have no idea. I usually just stop and clear the code or clear it when I get to work.
 

Cypress65

New Member
Joined
Aug 27, 2022
Messages
6
Reaction score
0
Points
1
Location
Md
Vehicle Year
03
Make / Model
Ford ranger
Transmission
Manual
Yeah that makes sense. No code here but it's the end if summer with it still being 80 plus here so no reason for it. I just Saud screw it. It goes up to half after a few mins so whatever I guess lol
 

Sponsored Ad


Sponsored Ad

Top