1991 N13 Nissan Pulsar Temperature Gauge Problem
Gabriel Ditu
I'm from Australia, so this car may have been sold as a different model
in other countries.
My problem is that most of the time the temperature gauge on the Pulsar
(Vector GL, 1.6L throttle body injection, 3sp automatic) does not move.
Every now and then it works fine, but for the most part it does not
indicate anything.
Here is a little more information:
* the fan cames on as normal when the temperature goes up, so I know
that a correct temperature reading comes from somewhere
* I checked the diagnostic function on the onboard computer and it
reports no faults, the ECM light does not come on, I know that it
should detect both voltage low and voltage high conditions, but the
voltage seems OK
* I have installed a new radiator and thermostat a few months ago and I
checked that all the hoses are in order and that there is plenty of
coolant in the system
Could someone please suggest a course of action from here? In
particular how many temperature sensors are there and where are they
located? How would I go about testing the sensors and the gauge?
I have a workshop manual complete with wiring diagrams and the like and
I am not afraid to tinker myself. I have taken the instrument cluster
out a cople of times already to change the bulbs. Unfortunately this
manual is very scarce in detail when it comes to specific electronic
components and rather focuses on mechanical problems.
Any help would be greatly appreciated! I am a student and can scarcely
afford to pay an auto electrician a few hours' labour.
Cheers,
Gabriel.
JM
news:<1132285575.1...@g49g2000cwa.googlegroups.com>...
> I'm from Australia, so this car may have been sold as a different model
> in other countries.
> My problem is that most of the time the temperature gauge on the Pulsar
> (Vector GL, 1.6L throttle body injection, 3sp automatic) does not move.
> Every now and then it works fine, but for the most part it does not
> indicate anything.
> particular how many temperature sensors are there and where are they
> located? How would I go about testing the sensors and the gauge?
Usually (at least in my limited experience), there is a separate sensor for
the gauge. On my Altima, the sensor is screwed into the engine where the
top rad hose fits on. It's a simple single wire connection with one of
those slide-on connectors. Yours is probably similar, it's just a matter if
finding where it's located.
Hope that helps!
Gabriel Ditu
Here is what I did, just in case other people are having the same
problem.
There are two temperature sensors. One for the gauge and one for the
ECM. The gauge sensor has a simple, spade type connector and is just
behind where the top radiator hose connects. The wire is yellow with a
green stripe. Further back you will find the ECM temperature sensor,
this one has a larger connector and is protected by a water jacket.
Altogether it looks much more important, I guess because it is.
If the ECM temperature sensor is playing up then the ECM light will
come on, as the ECM tests the voltage coming from that sensor. The
gauge sensor however has no such testing system.
To test that the temperature gauge is working correctly: pull out the
connector from the gauge sensor and earth it to the engine block. Do
this with the engine off but the key turned to the On position. Only
earth it for a couple of seconds and get an assistant to tell you if
the gauge moves. If it moves then the gauge and circuit is fine. This
means that you may have a fautly thermostat or a faulty sensor. To test
the thermostat you can start the engine and touch temperature test the
top radiator hose. The thermostat should only allow water to flow
through the hose after the engine has warmed up. Also, when removed
from the car a faulty thermostat will often be stuck open. Both the
thermostat and the gauge temperature sensor are relatively cheap and
easy to replace.
If the gauge does not move when the earth test is performed, then the
problem is either with the electrical wiring to the gauge or with the
gauge itself. Also be sure to clean the sensor contact and the wiring
connector as this may solve your problem.
At this point you more or less have to pull out the instrument cluster
assembly. If that sounds very scary to you then perhaps you should grab
some dinero and head to an auto electrician.
My gauge was working intermitently, so I figured that the gauge was
probably OK, and the problem was the circuit. One test you can try is
to reach behind the instrument cluster from under the dashboard, a
smaller hand helps, so if there is a helpful female around you might
want to enlist her help, and jiggle the wiring connector found on the
right hand side of the instrument cluster. This would often make my
temperature gauge work for a while and convinced me that this was where
the problem was located.
On speaking with an auto electrician aquaintance, they advised me that
a common problem on these cars are cracked solder joints on the
instrument cluster circuit board. Fits with the intermitent operation
symptoms.
So this is what I did. I pulled out the instrument cluster. First
remove and disconnect the hazard lights and rear demister buttons from
the cluster surround. Then remove the cluster surround by removing six
screws and pulling it out. Then remove the four screws holding the
actual instrument cluster in place. Once this is done, you won't be
able to pull out the cluster because of the two wiring connectors on
the back. Ease the cluster forward and you should be able to remove the
left wiring connector first, easy, then the right connector, harder.
Now that I had the cluster out I checked the wiring and the connectors,
everything was fine, so I continued with the pulling apart. The cluster
itself comes apart by unscrewing the screws on the back and removing
the front lens and surround.
Please be very careful here. If you are not supremely confident or
supremely desperate, you should probably get an an auto electrician to
look at your cluster. At least you will save on some labour costs by
pulling it out yourself. The cluster contains precision instruments and
electrical components and you may end up doing more harm than good.
Also the instrument fascia is very easily marked by sticky fingers.
Anyway, once the screws are off, you will see that the instrument
cluster is made up of two halves, connected by a small flat wiring
connector. I pulled the half with the temperature gauge out, which is
also the half with the large wiring connector on the back of it. Once
that is done, you will be holding a circuit board with the temperature
gauge and fuel gauge attached to it. I unscrewed some nuts this time
and removed the gauges to be left with the circuit board only.
Sure enough, some of the solder joints on the back of the wiring
connector were visibly cracked. I reflowed all of the cracked joints
and put it all back. At this point I would suggest you also replace all
the backlighting and warning light bulbs, since they are very cheap,
should be around $10 for about 15 bulbs, and will ensure you won't have
to pull out the instrument cluster again soon. The bulbs are not
soldered on, they are sitting in bulb holders and just screw in, so
this step is easy.
It all works now!
Let me warn you again, you may end up doing more harm than good and
spending more money. Most of the parts inside the cluster are not
available anymore, at least in Australia, since the car is 14 years
old, so if you damage something chances are it will be very hard to
find a replacement.
Cheers,
Gabriel.