'93 GC Coolant Temp Gauge problem
 

My '93 GC 4.0L 6cyl dashboard temp gauge has started going crazy. It
is bouncing between full cold and the correct center scale temperature.
It seems to be motor load dependant such that if I step on the gas the
gauge works, coasting the gauge drops. I wacked the dashboard and that
does not make the gauge work. I figure it is a bad connector or the
wiring is going bad at the sensor but my real question is where is the
dashboard gauge sender located on the engine?

I see one temp sensor at the front of the engine right near the
thermostat with two wires going to it but I think that one is for the
fuel injection. In my case the engine runs fine when the gauge is at
mininum temp, gas mileage is about the same as ever, and I am not
getting any check engine lights or codes so it seems as though there is
probably separate sensors. Can anyone give me a hint where the sender
is?

Walt B.

Re: '93 GC Coolant Temp Gauge problem
 

On the drivers side top rear of the head. Could be a purple wire if it
is like the old ones.

I would be checking the connection and if it's ok but looks pulled on
then I would be checking the engine and tranny mounts for a blown one.
A bad mount can let the engine move enough to pull on that wire.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

wb wrote:
>
> My '93 GC 4.0L 6cyl dashboard temp gauge has started going crazy. It
> is bouncing between full cold and the correct center scale temperature.
> It seems to be motor load dependant such that if I step on the gas the
> gauge works, coasting the gauge drops. I wacked the dashboard and that
> does not make the gauge work. I figure it is a bad connector or the
> wiring is going bad at the sensor but my real question is where is the
> dashboard gauge sender located on the engine?
>
> I see one temp sensor at the front of the engine right near the
> thermostat with two wires going to it but I think that one is for the
> fuel injection. In my case the engine runs fine when the gauge is at
> mininum temp, gas mileage is about the same as ever, and I am not
> getting any check engine lights or codes so it seems as though there is
> probably separate sensors. Can anyone give me a hint where the sender
> is?
>
> Walt B.

Re: '93 GC Coolant Temp Gauge problem
 

On the drivers side top rear of the head. Could be a purple wire if it
is like the old ones.

I would be checking the connection and if it's ok but looks pulled on
then I would be checking the engine and tranny mounts for a blown one.
A bad mount can let the engine move enough to pull on that wire.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

wb wrote:
>
> My '93 GC 4.0L 6cyl dashboard temp gauge has started going crazy. It
> is bouncing between full cold and the correct center scale temperature.
> It seems to be motor load dependant such that if I step on the gas the
> gauge works, coasting the gauge drops. I wacked the dashboard and that
> does not make the gauge work. I figure it is a bad connector or the
> wiring is going bad at the sensor but my real question is where is the
> dashboard gauge sender located on the engine?
>
> I see one temp sensor at the front of the engine right near the
> thermostat with two wires going to it but I think that one is for the
> fuel injection. In my case the engine runs fine when the gauge is at
> mininum temp, gas mileage is about the same as ever, and I am not
> getting any check engine lights or codes so it seems as though there is
> probably separate sensors. Can anyone give me a hint where the sender
> is?
>
> Walt B.

Re: '93 GC Coolant Temp Gauge problem
 

On the drivers side top rear of the head. Could be a purple wire if it
is like the old ones.

I would be checking the connection and if it's ok but looks pulled on
then I would be checking the engine and tranny mounts for a blown one.
A bad mount can let the engine move enough to pull on that wire.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

wb wrote:
>
> My '93 GC 4.0L 6cyl dashboard temp gauge has started going crazy. It
> is bouncing between full cold and the correct center scale temperature.
> It seems to be motor load dependant such that if I step on the gas the
> gauge works, coasting the gauge drops. I wacked the dashboard and that
> does not make the gauge work. I figure it is a bad connector or the
> wiring is going bad at the sensor but my real question is where is the
> dashboard gauge sender located on the engine?
>
> I see one temp sensor at the front of the engine right near the
> thermostat with two wires going to it but I think that one is for the
> fuel injection. In my case the engine runs fine when the gauge is at
> mininum temp, gas mileage is about the same as ever, and I am not
> getting any check engine lights or codes so it seems as though there is
> probably separate sensors. Can anyone give me a hint where the sender
> is?
>
> Walt B.

Re: '93 GC Coolant Temp Gauge problem
 

Thanks for the info. I'll take a look tonight after work. One
clarifying question. Is the sensor on the backside of the head facing
the firewall or on the drivers side of the head near the firewall end
(i.e. somewhere under the intake manifold)?

Walt B.

Re: '93 GC Coolant Temp Gauge problem
 

Thanks for the info. I'll take a look tonight after work. One
clarifying question. Is the sensor on the backside of the head facing
the firewall or on the drivers side of the head near the firewall end
(i.e. somewhere under the intake manifold)?

Walt B.

Re: '93 GC Coolant Temp Gauge problem
 

Thanks for the info. I'll take a look tonight after work. One
clarifying question. Is the sensor on the backside of the head facing
the firewall or on the drivers side of the head near the firewall end
(i.e. somewhere under the intake manifold)?

Walt B.

Re: '93 GC Coolant Temp Gauge problem
 

Right on the top corner pointing up.

Mike

wb wrote:
>
> Thanks for the info. I'll take a look tonight after work. One
> clarifying question. Is the sensor on the backside of the head facing
> the firewall or on the drivers side of the head near the firewall end
> (i.e. somewhere under the intake manifold)?
>
> Walt B.

Re: '93 GC Coolant Temp Gauge problem
 

Right on the top corner pointing up.

Mike

wb wrote:
>
> Thanks for the info. I'll take a look tonight after work. One
> clarifying question. Is the sensor on the backside of the head facing
> the firewall or on the drivers side of the head near the firewall end
> (i.e. somewhere under the intake manifold)?
>
> Walt B.

Re: '93 GC Coolant Temp Gauge problem
 

Right on the top corner pointing up.

Mike

wb wrote:
>
> Thanks for the info. I'll take a look tonight after work. One
> clarifying question. Is the sensor on the backside of the head facing
> the firewall or on the drivers side of the head near the firewall end
> (i.e. somewhere under the intake manifold)?
>
> Walt B.

Re: '93 GC Coolant Temp Gauge problem
 

wb did pass the time by typing:
> My '93 GC 4.0L 6cyl dashboard temp gauge has started going crazy. It
> is bouncing between full cold and the correct center scale temperature.
> It seems to be motor load dependant such that if I step on the gas the
> gauge works, coasting the gauge drops. I wacked the dashboard and that
> does not make the gauge work. I figure it is a bad connector or the
> wiring is going bad at the sensor but my real question is where is the
> dashboard gauge sender located on the engine?

Handy dandy ref:
http://members.cox.net/wilsond/Fixes/diagnostics.html

--
DougW

Re: '93 GC Coolant Temp Gauge problem
 

wb did pass the time by typing:
> My '93 GC 4.0L 6cyl dashboard temp gauge has started going crazy. It
> is bouncing between full cold and the correct center scale temperature.
> It seems to be motor load dependant such that if I step on the gas the
> gauge works, coasting the gauge drops. I wacked the dashboard and that
> does not make the gauge work. I figure it is a bad connector or the
> wiring is going bad at the sensor but my real question is where is the
> dashboard gauge sender located on the engine?

Handy dandy ref:
http://members.cox.net/wilsond/Fixes/diagnostics.html

--
DougW

Re: '93 GC Coolant Temp Gauge problem
 

wb did pass the time by typing:
> My '93 GC 4.0L 6cyl dashboard temp gauge has started going crazy. It
> is bouncing between full cold and the correct center scale temperature.
> It seems to be motor load dependant such that if I step on the gas the
> gauge works, coasting the gauge drops. I wacked the dashboard and that
> does not make the gauge work. I figure it is a bad connector or the
> wiring is going bad at the sensor but my real question is where is the
> dashboard gauge sender located on the engine?

Handy dandy ref:
http://members.cox.net/wilsond/Fixes/diagnostics.html

--
DougW

Re: '93 GC Coolant Temp Gauge problem
 

Well last night I easily found the sensor (Thanks everyone). The plug
was quite dirty and seemed loose. The sensor had dirt down where the
contact is. Its pretty tight working on it since the big wiring
harness is so close.

I cleaned up the plug and contacts and pressed it back on. However
it seems as though there was no click or snap and the plug was snug but
definately not a real tight fit. I am thinking that the postive
retaining aspect of the connector is maybe broken or worn out however
the gauge worked perfectly. I'll keep an eye on it.

Walt B.

Re: '93 GC Coolant Temp Gauge problem
 

Well last night I easily found the sensor (Thanks everyone). The plug
was quite dirty and seemed loose. The sensor had dirt down where the
contact is. Its pretty tight working on it since the big wiring
harness is so close.

I cleaned up the plug and contacts and pressed it back on. However
it seems as though there was no click or snap and the plug was snug but
definately not a real tight fit. I am thinking that the postive
retaining aspect of the connector is maybe broken or worn out however
the gauge worked perfectly. I'll keep an eye on it.

Walt B.

Re: '93 GC Coolant Temp Gauge problem
 

Well last night I easily found the sensor (Thanks everyone). The plug
was quite dirty and seemed loose. The sensor had dirt down where the
contact is. Its pretty tight working on it since the big wiring
harness is so close.

I cleaned up the plug and contacts and pressed it back on. However
it seems as though there was no click or snap and the plug was snug but
definately not a real tight fit. I am thinking that the postive
retaining aspect of the connector is maybe broken or worn out however
the gauge worked perfectly. I'll keep an eye on it.

Walt B.

Re: '93 GC Coolant Temp Gauge problem
 

wb did pass the time by typing:
> Well last night I easily found the sensor (Thanks everyone). The plug
> was quite dirty and seemed loose. The sensor had dirt down where the
> contact is. Its pretty tight working on it since the big wiring
> harness is so close.
>
> I cleaned up the plug and contacts and pressed it back on. However
> it seems as though there was no click or snap and the plug was snug but
> definately not a real tight fit. I am thinking that the postive
> retaining aspect of the connector is maybe broken or worn out however
> the gauge worked perfectly. I'll keep an eye on it.

Napa has a pigtail to replace that connector if the tab thingy
is broken. Don't know the number off-hand. You might also be able
to use a couple of zipties to hold it more secure.

--
DougW

Re: '93 GC Coolant Temp Gauge problem
 

wb did pass the time by typing:
> Well last night I easily found the sensor (Thanks everyone). The plug
> was quite dirty and seemed loose. The sensor had dirt down where the
> contact is. Its pretty tight working on it since the big wiring
> harness is so close.
>
> I cleaned up the plug and contacts and pressed it back on. However
> it seems as though there was no click or snap and the plug was snug but
> definately not a real tight fit. I am thinking that the postive
> retaining aspect of the connector is maybe broken or worn out however
> the gauge worked perfectly. I'll keep an eye on it.

Napa has a pigtail to replace that connector if the tab thingy
is broken. Don't know the number off-hand. You might also be able
to use a couple of zipties to hold it more secure.

--
DougW

Re: '93 GC Coolant Temp Gauge problem
 

wb did pass the time by typing:
> Well last night I easily found the sensor (Thanks everyone). The plug
> was quite dirty and seemed loose. The sensor had dirt down where the
> contact is. Its pretty tight working on it since the big wiring
> harness is so close.
>
> I cleaned up the plug and contacts and pressed it back on. However
> it seems as though there was no click or snap and the plug was snug but
> definately not a real tight fit. I am thinking that the postive
> retaining aspect of the connector is maybe broken or worn out however
> the gauge worked perfectly. I'll keep an eye on it.

Napa has a pigtail to replace that connector if the tab thingy
is broken. Don't know the number off-hand. You might also be able
to use a couple of zipties to hold it more secure.

--
DougW