Dash Temp. Gauge Problems - See Pics

badge49 · 03-05-2008, 12:04 AM

I replaced my thermostat today in an attempt to gain better fuel economy.

Last time my truck was in the shop they said I needed a new "temp. sensor" to make my non-opperating temperature gauge work again. (The dummy gauge on the left side of the gauge bezel)

Since the thermostat and the temp. sensors are next to each other, I figured I'd fix the problem and get my gauge back. Auto Zone sold me a $6 temp. sensor and I replaced the old one. Unfortunately, the temp. gauge in my dash still does not work/move. There is a smaller temp. sensor next to the one I replaced...could that be the defunkt sensor? Has anyone else had this problem? Any other ideas why a temp. gauge may not work?

Old thermostat (190*), new sensor, new thermostat (192*)

Thermostat and sensor(s) location:

Old corroded sensor and new replacement sensor:

marragtop · 03-05-2008, 10:37 AM

I couldn't view your pics, but assuming you have the 4.0, the coolant temperature sensor is above the water pump mounted on the intake. Follow this linkhttp://www.autozone.com/N,4294897631/shopping/locsSelect.htm.

I'm not sure what AZ sold you. $6 seems too cheap for the temperature sensor. You can try grounding the wire on the sensor. This should peg the temp gauge to Hot. If it doesn't, your problem may be the gauge or the wiring.

badge49 · 03-05-2008, 11:30 AM

Autozone's site doesn't show temp. sensor locations for a '97.

I got to thinking...why are there two sensors next to each other? Why not just wire both together and only have one? You can see my two coolant temp. sensors just behind the thermostat housing, in the picture above.

I might just replace the smaller one ragardless, the price was cheap

96eb96 · 03-05-2008, 12:06 PM

Quote:

Originally Posted by badge49

Autozone's site doesn't show temp. sensor locations for a '97.

I got to thinking...why are there two sensors next to each other? Why not just wire both together and only have one? You can see my two coolant temp. sensors just behind the thermostat housing, in the picture above.

I might just replace the smaller one ragardless, the price was cheap

One reports to the computer, one to your dashboard. The one in the pic is for the computer. The dashboard SENDER has one wire. Why 2 sensors? Because electrically they have different resistance characteristics and the equipment has different requirements.

Won't hurt to replace both, especially if you are DIY. one less thing to fail in the future. The single wire one for the dash is the one that usually has issues though...

badge49 · 03-05-2008, 12:40 PM

Cool, so I replaced the one for the computer, which may explain why my dash gauge still does not work.

Replacing the other sensor should do the trick? If not, what's the easiest way to pull the actual gauge?

96eb96 · 03-05-2008, 05:44 PM

Quote:

Originally Posted by badge49

Cool, so I replaced the one for the computer, which may explain why my dash gauge still does not work.

Replacing the other sensor should do the trick? If not, what's the easiest way to pull the actual gauge?

Test your gauge by pulling off the single wire and momentarily touching it to the engine body. The gauge should pin all the way (the gauge has a delay so you dont really need a helper). If it pins replace the sender. They are a failure item.

I did a bit of research I believe the thing you are holding is the temperature sender for the dash. How many wires are in there? The computer one is tapered. I have the OHV and it it looks a bit different.

badge49 · 03-06-2008, 10:37 AM

I think I'm a little confused. Is "sender" another word for "sensor," or are they two different parts? Also, both of the sensors I saw have two wires going into the plug. The plugs are slightly different, so you can't mis-match them. Thanks for the continued help

96eb96 · 03-06-2008, 11:59 AM

Quote:

Originally Posted by badge49

I think I'm a little confused. Is "sender" another word for "sensor," or are they two different parts? Also, both of the sensors I saw have two wires going into the plug. The plugs are slightly different, so you can't mis-match them. Thanks for the continued help

A sender generally sends information to a gauge. Examples are temperature, fuel and oil. A Sensor senses information for a computer.

Sensor for the computer:
http://www.partsamerica.com/ProductD...pe=290&PTSet=A

Sender for the dash: ( I believe you replaced it)
http://www.partsamerica.com/ProductD...pe=425&PTSet=A

The sender has two wires. One is probably a ground. Remove the harness. I believe if the harness is shorted your temp gauge will max out if it is working.

badge49 · 03-06-2008, 12:21 PM

Ah, ha...I'm about to head out to work on some other parts, so I'll check that out. I'll report back tonight.

badge49 · 03-07-2008, 07:57 PM

Here's my update: Went to Autozone, they sold me what they said was the "other" sensor...turns out it was the wrong part. The second trip there yeilded the correct sensor. I tried to get the dash gauge to react by shorting the sensor's wire harness, but nothing happened. I replaced the sensor with the new one...and nothing happened. Check out the pictures from today; I'm open to ANY suggestions at this point. I mean, how hard can it be to make a little gauge work!!!

Tried short circuiting the sensor...no luck:

Trip #1 to AZ ended with the wrong part, obviously:

Trip #2 to AZ ended with the correct part:

It's been dead ever since I bought the truck. The only part I didn't break!

96eb96 · 03-07-2008, 09:06 PM

Quote:

Originally Posted by badge49

Here's my update: Went to Autozone, they sold me what they said was the "other" sensor...turns out it was the wrong part. The second trip there yeilded the correct sensor. I tried to get the dash gauge to react by shorting the sensor's wire harness, but nothing happened. I replaced the sensor with the new one...and nothing happened. Check out the pictures from today; I'm open to ANY suggestions at this point. I mean, how hard can it be to make a little gauge work!!!

Tried short circuiting the sensor...no luck:

Trip #1 to AZ ended with the wrong part, obviously:

Trip #2 to AZ ended with the correct part:

It's been dead ever since I bought the truck. The only part I didn't break!

If the sensor never budges from that C mark it is likely that the gauge is fried.

The manual states to check continuity from one sensor lead (R/W) wire to the instrument cluster harness. If that is ok, there are a few tests on the cluster itself to determine if the gauge or cluster panel printed circuit is bad.

This is a very simple setup with no computers involved!

I can post some wiring diagrams if you want.

badge49 · 03-08-2008, 02:10 AM

I should'a thought to check the continuity while I was in there. What do I do if there is none? Also, is there an easy way to just pull the gauge itself and make sure that it's not fried? (I'm tempted to just splice in my own bypass harness from the gauge to the sensor)

Bill MacLeod · 03-08-2008, 02:40 AM

The temp sending unit for an SOHC engine will have a 2 wire connector. Red/white strip to gauge, black/white strip to ground. Needs the seperate ground because of the composite manifold.

At low temp, there will high resistance and at higher temps there will be lower resistance across the terminals.

badge49 · 03-08-2008, 02:54 AM

What are my options after I test continuity? If there is cont., then what. If there isn't, then what? It's 1am here right now, so it'll have to wait till later either way.

Bill MacLeod · 03-08-2008, 03:16 AM

Look for a ground wire in the harness on top of the rad shell. I think it is screwed in the vicinity of the rad cap and above the drivers side head light. You would be able to isolate the ground wire and verify continuity.

Check for resistance across the sender terminals.

I'll see if I can find some specs on the sender.

96eb96 · 03-08-2008, 10:49 AM

Quote:

Originally Posted by badge49

I should'a thought to check the continuity while I was in there. What do I do if there is none? Also, is there an easy way to just pull the gauge itself and make sure that it's not fried? (I'm tempted to just splice in my own bypass harness from the gauge to the sensor)

Here is the cluster test. Pull your instrument cluster.

Measure the resistance between the instrument cluster temperature gauge clip "B" and the instrument cluster temperature gauge clip "S."
Measure the resistance between the instrument cluster temperature gauge clip "S" and the instrument cluster temperature gauge clip "G."

Is the resistance 235 +/- 21 ohms between the "B" clip and "S" clip; and 100 +/- 10 ohms between the "S" clip and "G" clip?
YES
REPLACE the instrument cluster printed circuit. TEST the system for normal operation.

NO
REPLACE the engine coolant temperature gauge (10883). TEST the system for normal operation

The first picture shows the cluster harness. The lead indicated is connected to the sender, you can check continuity. I believe it is a red/white wire:

1)Measure the resistance between instrument cluster C287-3, circuit 39 (R/W), and water temperature indicator sender unit C163, circuit 39 (R/W).

2)Measure the resistance between instrument cluster C287-3, circuit 39 (R/W), and ground

Is the resistance less than 5 ohms between instrument cluster C287 and water temperature indicator sender unit C163; and greater than 10,000 ohms between instrument cluster C287 and ground?
YES
GO to B3 .

NO
REPAIR circuit 39 (R/W). TEST the system for normal operation.

Second Picture tests the instrument cluster ground:

Check the resistance between instrument cluster C287-2, circuit 570 (BK/W), and ground.

Is the resistance less than 5 ohms?
YES
GO to B5 .

NO
REPAIR circuit 570 (BK/W). TEST the system for normal operation.

The last pin (after those two) is cluster power, but I doubt that is the problem since your other instruments work.

badge49 · 03-08-2008, 01:33 PM

Thanks, I'll work on this and report back. What does a "printed circuit" look like? (If I do need to replace/repair it)

L4CX · 11-04-2008, 09:03 PM

Ok, I'm kind of bringing this back from the dead...But is it possible to just buy a cheaper temp gauge/Sender combo and run the wire for the new gauge? I'm going to be digging into a project similar to this and was wondering if it would be possible.
I have the OHV. So Basically I'm looking for the sender above the T-stat with ONE wire?

Oh yeah, badge49, a Printed ciruit is the green Circuit board that makes up the guage clusters on our trucks. How's it coming? Did you get it figured out?

420Mud Devil561 · 12-20-2008, 10:17 AM

Did anyone ever fix this?If so please post it.Thanks in advanced.

03-08-2008, 02:40 AM	#13
Bill MacLeod Wannabe Elite Explorer Hamilton, Ontario 06 Ltd & 99 E/B Join Date: Nov 2000 Posts: 378 Vehicle Specs	The temp sending unit for an SOHC engine will have a 2 wire connector. Red/white strip to gauge, black/white strip to ground. Needs the seperate ground because of the composite manifold. At low temp, there will high resistance and at higher temps there will be lower resistance across the terminals. __________________ 06 Ltd, V8, blk/blk, nav, dvd, quads, mich ms2 265/60/18 99 E/Bauer sohc, 4.10, k&n, kenwood kiv-700, E/S s/b bushings, autometer pod & gauges, kyb mono-tube. 95 Mustang 5.0 GTS - aode,supercooler, 3.55 frpp, cobra intake, 1.7 r/r, bbk ceramic shorties, alum pullies,sub-frames, k&n, taylor 409, autometer gauges, bullit suspension w/03 cobra bilstein struts, UHP 245/275 on 2000 GT 5 spokes, 99 pbr calipers.

03-08-2008, 03:16 AM	#15
Bill MacLeod Wannabe Elite Explorer Hamilton, Ontario 06 Ltd & 99 E/B Join Date: Nov 2000 Posts: 378 Vehicle Specs	Look for a ground wire in the harness on top of the rad shell. I think it is screwed in the vicinity of the rad cap and above the drivers side head light. You would be able to isolate the ground wire and verify continuity. Check for resistance across the sender terminals. I'll see if I can find some specs on the sender. __________________ 06 Ltd, V8, blk/blk, nav, dvd, quads, mich ms2 265/60/18 99 E/Bauer sohc, 4.10, k&n, kenwood kiv-700, E/S s/b bushings, autometer pod & gauges, kyb mono-tube. 95 Mustang 5.0 GTS - aode,supercooler, 3.55 frpp, cobra intake, 1.7 r/r, bbk ceramic shorties, alum pullies,sub-frames, k&n, taylor 409, autometer gauges, bullit suspension w/03 cobra bilstein struts, UHP 245/275 on 2000 GT 5 spokes, 99 pbr calipers.

11-04-2008, 09:03 PM	#18
L4CX Wannabe Elite Explorer East Lansing, MI 96 XLT Join Date: Apr 2007 Posts: 293 Vehicle Specs	Ok, I'm kind of bringing this back from the dead...But is it possible to just buy a cheaper temp gauge/Sender combo and run the wire for the new gauge? I'm going to be digging into a project similar to this and was wondering if it would be possible. I have the OHV. So Basically I'm looking for the sender above the T-stat with ONE wire? Oh yeah, badge49, a Printed ciruit is the green Circuit board that makes up the guage clusters on our trucks. How's it coming? Did you get it figured out? __________________ Scott "CasaNova" Keef ZAPV7 and ZAPB1 (Zombie Attack Preparedness Bus) United Christian Off Road Alliance Lifted 4 Christ Truck Club Proof I have To much to do Already

12-20-2008, 10:17 AM	#19
420Mud Devil561 Wannabe Elite Explorer Palm Beach Florida '95 Explorer EB Join Date: Dec 2008 Posts: 2 Vehicle Specs	Did anyone ever fix this?If so please post it.Thanks in advanced. __________________ '95 Explorer 7" and 35's

03-05-2008, 12:04 AM	#1
badge49 Wannabe Elite Explorer Humboldt, CA '97 XLT 4X4 Join Date: Sep 2005 Posts: 569 Vehicle Specs (Original Poster)	Dash Temp. Gauge Problems - See Pics I replaced my thermostat today in an attempt to gain better fuel economy. Last time my truck was in the shop they said I needed a new "temp. sensor" to make my non-opperating temperature gauge work again. (The dummy gauge on the left side of the gauge bezel) Since the thermostat and the temp. sensors are next to each other, I figured I'd fix the problem and get my gauge back. Auto Zone sold me a $6 temp. sensor and I replaced the old one. Unfortunately, the temp. gauge in my dash still does not work/move. There is a smaller temp. sensor next to the one I replaced...could that be the defunkt sensor? Has anyone else had this problem? Any other ideas why a temp. gauge may not work? Old thermostat (190), new sensor, new thermostat (192) Thermostat and sensor(s) location: Old corroded sensor and new replacement sensor:

03-05-2008, 10:37 AM	#2
marragtop Wannabe Elite Explorer balt, md 91 xlt, 92 xlt, 95 xlt Join Date: Apr 2001 Posts: 2,074 Vehicle Specs	I couldn't view your pics, but assuming you have the 4.0, the coolant temperature sensor is above the water pump mounted on the intake. Follow this linkhttp://www.autozone.com/N,4294897631/shopping/locsSelect.htm. I'm not sure what AZ sold you. $6 seems too cheap for the temperature sensor. You can try grounding the wire on the sensor. This should peg the temp gauge to Hot. If it doesn't, your problem may be the gauge or the wiring. __________________ '88 F150 4x4 '91 Explorer XLT 4x4 '92 Explorer XLT 4x4 '95 Explorer XLT 4x4 If it don't = 16 (4x4), it ain't worth driving...

03-05-2008, 11:30 AM	#3
badge49 Wannabe Elite Explorer Humboldt, CA '97 XLT 4X4 Join Date: Sep 2005 Posts: 569 Vehicle Specs (Original Poster)	Autozone's site doesn't show temp. sensor locations for a '97. I got to thinking...why are there two sensors next to each other? Why not just wire both together and only have one? You can see my two coolant temp. sensors just behind the thermostat housing, in the picture above. I might just replace the smaller one ragardless, the price was cheap

03-05-2008, 12:40 PM	#5
badge49 Wannabe Elite Explorer Humboldt, CA '97 XLT 4X4 Join Date: Sep 2005 Posts: 569 Vehicle Specs (Original Poster)	Cool, so I replaced the one for the computer, which may explain why my dash gauge still does not work. Replacing the other sensor should do the trick? If not, what's the easiest way to pull the actual gauge?

03-06-2008, 10:37 AM	#7
badge49 Wannabe Elite Explorer Humboldt, CA '97 XLT 4X4 Join Date: Sep 2005 Posts: 569 Vehicle Specs (Original Poster)	I think I'm a little confused. Is "sender" another word for "sensor," or are they two different parts? Also, both of the sensors I saw have two wires going into the plug. The plugs are slightly different, so you can't mis-match them. Thanks for the continued help

03-06-2008, 12:21 PM	#9
badge49 Wannabe Elite Explorer Humboldt, CA '97 XLT 4X4 Join Date: Sep 2005 Posts: 569 Vehicle Specs (Original Poster)	Ah, ha...I'm about to head out to work on some other parts, so I'll check that out. I'll report back tonight.

03-07-2008, 07:57 PM	#10
badge49 Wannabe Elite Explorer Humboldt, CA '97 XLT 4X4 Join Date: Sep 2005 Posts: 569 Vehicle Specs (Original Poster)	Here's my update: Went to Autozone, they sold me what they said was the "other" sensor...turns out it was the wrong part. The second trip there yeilded the correct sensor. I tried to get the dash gauge to react by shorting the sensor's wire harness, but nothing happened. I replaced the sensor with the new one...and nothing happened. Check out the pictures from today; I'm open to ANY suggestions at this point. I mean, how hard can it be to make a little gauge work!!! Tried short circuiting the sensor...no luck: Trip #1 to AZ ended with the wrong part, obviously: Trip #2 to AZ ended with the correct part: It's been dead ever since I bought the truck. The only part I didn't break!

03-08-2008, 02:10 AM	#12
badge49 Wannabe Elite Explorer Humboldt, CA '97 XLT 4X4 Join Date: Sep 2005 Posts: 569 Vehicle Specs (Original Poster)	I should'a thought to check the continuity while I was in there. What do I do if there is none? Also, is there an easy way to just pull the gauge itself and make sure that it's not fried? (I'm tempted to just splice in my own bypass harness from the gauge to the sensor)

03-08-2008, 02:54 AM	#14
badge49 Wannabe Elite Explorer Humboldt, CA '97 XLT 4X4 Join Date: Sep 2005 Posts: 569 Vehicle Specs (Original Poster)	What are my options after I test continuity? If there is cont., then what. If there isn't, then what? It's 1am here right now, so it'll have to wait till later either way.

03-08-2008, 01:33 PM	#17
badge49 Wannabe Elite Explorer Humboldt, CA '97 XLT 4X4 Join Date: Sep 2005 Posts: 569 Vehicle Specs (Original Poster)	Thanks, I'll work on this and report back. What does a "printed circuit" look like? (If I do need to replace/repair it)