MG1600 temperature torture

[n2oxide]

HELP ! Can anyone help me with my temperature sender/transmitter on my MG1600 ? I have tried now, about a dozen, different senders ( some rover, some unipart, some intermotor - all listed for the MG1600 - have even tried ones from my other cars - 9 classics ) but I am not getting a reading to my gauge via any senders. If I earth the wire from the sender, the gauge gently lights up all bars, goes to the red and then Nicolette does her moaning............
SO, its not the cable, its not the gauge, solder joints or anything like that. I even put in my spare dashboard. The guage is working, I AM JUST NOT GETTING A READING FROM THE SENDER. DOES ANYONE HAVE ONE ? DOES ANYONE HAVE ANOTHER TRAIN OF THOUGHT HERE ?
I really am just going to sort the car out with some paraffin and a match soon ( not joking here ! ) as my own temperature is rising and for a £100 heap of rust, its not worth the bother..........................right now I will get more pleasure watching it burn than driving it.
I have had lots of help from you guys so far, but nothing to get the gauge working. Funny thing is EVERYTHING ELSE is tip top and A1 which is very rare on a MG1600 !

Perry

[E_T_V]

Is the engine actually getting up to temperature? If the thermostat is stuck open or missing then the engine won't get hot and won't read very high (if at all) on the gauge.

[G51 NAV]

If you're genuinely sick of the car I'm sure a few people here will be happy to take it off yours hands. MG1600s are like gold-dust, working temp sender or not.

[Russ]

Its a long shot but it could be the thermostat housing isnt earthed, do an earth continuity test on it or try earhting the sender wire on it and listern for nicollette

[G Force]

Hi Perry

I agree with Dan "E_T_V" I would guess the engine won't be getting up to temperature due to a sticking thermostat. It would not be unusual for the gauge not to move at all this time of year if the stat was faulty. Run the engine at 2000rpm until the radiator cooling fan kicks in, If the gauge isn't registering 3/4 by then, then ok its time for more thinking.

[n2oxide]

more torture

Engine is definatley up to temp, (she's inside), all hoses hot to touch, occasional fan kicking in. Today I used a brand new mini sender ( GTR 101 / GTR 143 ) which is supposed to be the correct one and still no joy. And an Austin Maxi one and still no joy. My thoughts were that the sender was not getting any heat or an earth through the thermostat housing so this is what I did.

I carefully secured, soldered and sealed with rubber tape the mini sender to a cable; I fixed this cable to the chassis; I then connected the output of the sender to the gauge and promptly dropped it in a jug of just boiled out of the kettle water.............the guage did not move..........even after a minute or so. I took the sender out, removed the connector to the guage and placed it against the probe where it had earth from the chassis and Nicolette went into overload !

Its the sender; I can't seem to get the right one; ALL I NEED IS THE SPECS. and am sure I could get one to fit that would do the job, even with a few adaptors or some fabrication work to the thermostat housing. At what range does it send a signal to the guage/dashboard. At least if I knew this then I would have a chance !

T O R T U R E D !

[Russ]

It hasnt been fitted with thread tape in the past has it?

[Russ]

Is it R or S series as the S series one is 2 pin and the R single like maxis etc

[n2oxide]

R series - Maxi Engine - Single wire for sure.........
My next aggravated evening will be taking the airbox out of the way; taking the thermostat housing off and giving it a clean out in some acid ! Just in case there is bad contact onto the senders.............

But this does not explain why the supposedly correct sender did not work when I hard wired it today to force a reading...............

Perry

[digital efi]

My thoughts are leading me towards high resistance in the wiring between the sender unit and the instrument pack.

Try a wire direct from the sender terminal back to the appropriate input on the instrument pack, effectively bypassing the car wiring loom.

The only other possibility I can think of is that there is an internal fault on the instrument pack and your spare pack has the same fault: can you rig it up off the car with a known good sender and the aforementioned pot of hot water?

[n2oxide]

My thoughts are exactly what everyone is suggesting;

But no one and myself ( and my sparky ) cannot explain why the gauge nicely creeps up to hot hot hot and Nicolette has her moan when I earth the sender's signal wire ? Surely, if the guage was not working, it would not work when I earth the signal wire ?

Does this signal cable go direct to the pack OR does it pass through some weird fuel computer or something ?

If its got tits, wheels or silicone chips, it will give you trouble..............

[n2oxide]

And the spare pack is BRAND NEW - yes BRAND NEW - long story.............

[E_T_V]

Find the terminal on the dash that the sensor connects to. If you get stuck I'll have a look at mine.

Then measure the reistance to earth through this terminal.

Then measure the resistance to earth directly at the sensor. If there is a significant difference you've found the problem.

[Russ]

The wire does go strieght to the dash on the R series MG, the other thing to try is a jump lead round the hex of the sender to a good earth an see if that makes any difference

[G Force]

Does this signal cable go direct to the pack OR does it pass through some weird fuel computer or something ?

If its got tits, wheels or silicone chips, it will give you trouble..............

Not on the MG, it does on the VDP with electronic choke. You could check the voltage at the temperature sensor. it should be regulated to 10V, if not proceed down the road of a possible high resistance between the guage and sensor first.