Nissan Patrol 4x4 (Africa)

Peter, my coolant temps. have been partly sorted out from those very high readings that I originally was getting, as well as the fluctuating, and very high voltages, since my recently "repaired" alternator gave up the ghost on my way down to knysna over the easter weekend and I had to replace the alternator in Bloem (remember it was pushing 15.3 volts after replacing regulator & rectifier), now it is showing a normal and constant 14.3 / 14.4 volts with no fluctuations whatsoever - since then, my coolant is pretty much ok - except when I use the lights (it then shoots up from a steady 91 / 92 deg C to 96 / 97 deg; and then with brights and spots it increases to 110 and over - then if you indicate it shoots up further with each flash and the same applies when switching on any other electrics). Another point is that this only occurs once the engine has warmed up, and also the increase is greater at higher RPM's, in the day (without lights on) the increases in temp are not as hectic, but clearly noticeable when indicating, using aircon, hooter etc.

Sorry Pete I should have mentioned that the original fault was alternator related. Also the system does have all it's own probes ie. there is no sharing going on, madman coolant sensor has been installed on the thermostat's outer housing / casing. So how the two temp systems affect each other beats me!!

Tony,
If you say the Madman thermostat is fitted to the outer housing, are you referring to the metal casting?
Bruin Beer

Bruin Beer wrote:Tony,
If you say the Madman thermostat is fitted to the outer housing, are you referring to the metal casting?
Bruin Beer

Here's a pic of my Madman installation's coolant temperature sensor...

Ahhh... me thinks Tony has a set up where the temperature is measured from what looks like a "copper washer" with wires attached to it that connects to the Madman. This measures the cylinder head temp, and not the water temp. This is then fitted using one of the bolts from either the thermostat housing or a bolt connecting directly to the cylinder head to get a reading. It doesn't in any way come into contact with any water!!!

Somewhere along the lines there is a wire in the wrong place as its probably picking up some voltage through the head and that's feeding back to the Madman ( I'm no electrician so I might be way off track on this). My MGL has this type of connection available to measure 2 CHT's. Mine also started showing wild temp figures or 200 odd deg C, so I just disconnected it as the CHT is not as accurate as a water temp gauge.... even the dash temp gauge. I think is a better indication.

When I get a Madman fitted, I'll definitely get the water temp sensor fitted

Tony, this may just be me, but if there is a seperate water temperature sensor for the madman, which was supplied with the madman, then how in blazes can they tell you that the system is not compatable with your car because your car uses a 5-volt sensor?

Either Cedric is right, or there's a bad earth somewhere. This is not an inherent fault with either the MAdman or the Patrol, it is an installation issue.

Well according to Myngardt, there is a wire inside (in contact with the water) so they must have drilled through the casing. I have attached a photo of the coolant sensor, followed by I presume the boost sensor, and lastly the EGT sensor. I apologise for the poor focusing but you can all see what the installation looks like. (The EGT sensor is too difficult to get to, it is installed in front of the turbo, and the photo was taken sideways - sorry I should have rotated it!)

Hmm... ok my theory is out the window.... that water sensor looks like it is the correct set up. Must be a bad earth .... What if you ran a wire from the negative on the battery to the body of where that sensor connects to. Maybe onto that bolt where the red gasket sealer is. Then drive around and see if there is a difference. Not sure what size wire to use though

Cedric,
That was where I was going.
There is a ground issue between the engine (reference point for all the input sensors) and the Madman ground (measurement ground) which I would guess was connected somewhere inside the car close to the Madman installation.
I would suggest un-doing the Madman ground and connect that to the engine (or bolt described by you).
Test and verify.
Hope this helps
Bruin Beer

Thanks gents i'll try and let you know what happens, cheers.

Hello.
Ek het nie al die vorige posts gelees nie. Verskoon as ek iets sou herhaal.
n Madmad kan nie 2 pressures doen nie. Net olie druk of net boost.
Madman gebruik sy eie sensors. MAW hy word nie gekoppel op huidige sensors nie. Peter het so iets genoem.
Let op as jy n sensor monteer dat die sensor ordentlik grond. Passop vir thread tape om nie die grond te breek nie, al sit die sensor in metaal wat gegrond is.
Groete