Temperature Gauge Citroen ZX

[naim22]

Hi all,

I currently own a 1992 Citroen ZX 1.9D NA XUD9 Non AC. It's absolutely brilliant and I intend to keep it for a long time as I absolutely love it. However one thing that I'm a bit wary of is the lack of a temperature gauge.
It has a tell-tale for the water temperature but from my experience of other cars that light tends to only mean one thing when it lights up. The car is Cooked and its too late to try and save it.

Given the XUD's reputation for overheating and the fact it requires the cooling system to be kept on top a little more than most cars (I have just flushed the coolant and renewed the water pump). I was hoping it would be possible to swap the clocks over for a set with a temp gauge and transfer my speedo also. This way I could spot any abnormal rise in temp should it happen and shut the car off.
I have done this in the past in both a mercedes and a VW (to gain a tacho in those instances as neither of the analog clocks worked!).
I imagine the temp sensor will need changing also as its likely currently a switch.

Has anyone done this or anything similar? Any tips? Is the wiring present on all cars or will I have to run some extra?

I've seen a set like the ones in the image below for sale, however on my car the temp light is on the opposite side to the temp gauge on the image below (where the fuel gauge is on the picture), and I have an oil pressure light where the temp gauge is on the picture. My fuel gauge is on the top. Does that mean I need a cluster out of an earlier car? Also my cluster has VDO clocks and not Jaeger.



My current cluster looks identical to this (with a MPH speedo)


Thanks very much

[white exec]

I've done roughly what you describe, around XUD9, but on a BX19RD, and for the same reasons.

Take a look at the thermostat/coolant output housing (where IIRC the temp sensors are fitted), and identify the sensors fitted. You might have to replace a hi temp warning switch with a temp sensor/transmitter, or it might be there (or a space for it) already.

All those temp sensors and switches are still available new, so should be easy to find. Circuit diagram for your ZX is essential for the work - do not rely on Haynes. If you post your VIN and RP number, I'm sure someone here can provide the proper circuit. It is not complicated electrically, as you know.

I used to run a ZX Avantage 1.9D NA Auto for work. Took it from new to 96k miles in 2.5 years. Great fun, especially when not carrying vast loads!

[naim22]

I've done roughly what you describe, around XUD9, but on a BX19RD, and for the same reasons.

Take a look at the thermostat/coolant output housing (where IIRC the temp sensors are fitted), and identify the sensors fitted. You might have to replace a hi temp warning switch with a temp sensor/transmitter, or it might be there (or a space for it) already.

All those temp sensors and switches are still available new, so should be easy to find. Circuit diagram for your ZX is essential for the work - do not rely on Haynes. If you post your VIN and RP number, I'm sure someone here can provide the proper circuit. It is not complicated electrically, as you know.

I used to run a ZX Avantage 1.9D NA Auto for work. Took it from new to 96k miles in 2.5 years. Great fun, especially when not carrying vast loads!

Are the circuit diagrams available on service.citroen? If not I'll post my VIN up in a bit as I dont have it to hand atm. Not sure what RP number is? (new to these cars still, sorry!)
If I replace the switch with a sensor, it will mean the high temp indicator on the gauge won't work? (i suppose not an issue really as the actual gauge is more important IMO)
I dont think I'll have the wiring for both sensors preinstalled even if there is space on the housing for both sensors. I guess I could run my own but routing it could be a pain.

How easy was the BX cluster to find? ZX clusters do not seem to be common at all. (Serves me right for getting a Reflex, though 60K mileage from new was too good to turn down!)

My 190D felt much much slower even though that was a 2.0D NA. I'm really impressed with the XUD so far, the simplicity is brilliant.

Thanks very much

[white exec]

This shows the possible components for the ZX 1.9D water outlet:



There are 3 sensor/switch positions on the outlet/thermostat housing.
If you don't have AC, one is actually spare (plugged), which might allow you to have both gauge and switch.

Circuit diagram:
I don't have any ZX circuit diagrams, but someone here surely will.
To get the right one, the RP (ORGA) number is needed. This fixes the exact production date for the vehicle.
Again, long time since I had a ZX, can't remember where the number is located. Again, someone will have the answer.

You might have to add some wiring, but it should be simple enough.
My replacement 'new' dash came from a scrapyard, and provided everything I needed.

[naim22]

Here is a photo of my temp sensor


Looks like there are two spaces. One appears to be plugged and the other is the switch? I'll have to run connectors/wiring ( ) or could I just do away with the switch entirely and replace with the sensor?

The final question would be whether the pinout cluster side is the same (probably unlikely if they use two separate sensors for warning and gauge). Is it easy to pin swap on these connectors? I have only done this on BMW's and JLR cars which both use Tyco connectors.

If anyone has a picture of their temp sensor setup on a ZX (with temp gauge and warning light) then I can look to replicate the OEM look.

Someone also said these have two fans that kick in at different times, and these can be used as a 'warning'?

Thanks

[white exec]

You will need to acquire an instrument cluster from a similar ZX, which has the instruments you require.

At the same time, if doing this in a breaker's yard, try to get hold of the temperature sender from the same vehicle, or, if this isn't possible, try to find the exact model, year, engine, etc. of the vehicle the new dash panel came from. Better still, get the vehicle's VIN number, and from that we tell everything there is to know about the car. The reason for is is that the temp gauge and sender need to be of the right type to work together. Guesswork might be good enough, but a "correct pair" is a safer bet.

You might as well retain your existing temp warning switch, and use the blanked off location (bolthead in photo) for the temp sensor for your new coolant temp gauge.

If you have two fans, they are controlled by a 3-pin "thermoswitch" (usually mounted in the radiator side). This switch closes in two stages, at a high temp and then a higher one. At high temp, the fans are switched on in series (and run at slow speed); at the upper temperature, the fans are switched into parallel (and both run at full speed). This switching is done with a cluster of three relays, working together.

It would be possible to use the LO and HI outputs from the thermoswitch to operate (even two) warning lights on the dash, to tell you when the fans were cutting in. (I did this on my dash conversion, using unused amber and red indicators on the new dash panel.)

Circuit diagram for your car needed. Hopefully someone can post this - Instrumentation diagram needed.