Madman not compatible with Patrol??

[Tony]

Just returned from a second trip to SAC in Centurion to sort out issues with my madman gauge: (using any electrical device ie: lights, indicators, hooter, fan, aircon etc.. pushes the coolant temp. reading up) I was first told by Mynhardt to bring the car in, it was an earthing fault and they had picked it up on one or two other Patrols. When I got there, he tried to send me home blaming my alternator (again)! I told him that I just replaced the bloody thing in Bloem 2 weeks ago, when it died on me, so please try another line! After much convincing, he decided to get the guys to take a look - and after almost an hour he came to tell me that they had discovered something new only on the Patrol. Something to do with the OEM temperature sensor working on 5 volts (as opposed to 12v) and that this is interfereing with the madman. When they removed the connection to the Nissan temp. sensor, madman worked fine. Does anyone know about this - surely the Hard Body will have the same sensor and the same issues?

So gents, apparently only Nissan Patrol operates in this way which means that all of you guys having installed one of these units will have the same problem. Please come back to me as I really hope it's not another thing wrong with my car!
Cheers.

P.S. It is the madman that shows EGT; Boost pressure; Voltage; Coolant temp and has the facility to show Oil pressure as well - although they never connected it; they supposedly can only do one pressure reading.

[Jorrie]

Fortunately I have a 4500 GRX Petrol . But what Tony is reporting here does not sound good!!

[marakasmalan]

Get one of the smart guys on this forum to make an adaptor cicuit board - if you speak electronics fluently it should be something along the lines of a transistor and a few resistors. In the old days electricians could understand that, as it formed part of the appyship, in recent times that ship sank...

You need to amplify the signal to 12v, which is not that difficult, and a variable resistor should allow for calibration.

I know a few varsity students who should be able to sort this issue - but they prostitute their skills, always, for beer or money...

[ChristoSlang]

My Patrol's Madman system works like an absolute charm and I have coolant temperature, coolant level, oil pressure, oil temperature and EGT connected. The temperature sometimes reads higher than I would like it to, but that's because the coolant gets hotter than I'd like it to - no use shooting the messenger!

The Madman system uses its own dedicated VDO temperature sender to monitor coolant temperature, and this has nothing at all to do with the Patrol's native sender unit.

As with any electrical sender unit it also needs to have a good electrical earth to give proper readings...

[Peter Connan]

Christo, after numerous discussions with Tony, I know that the temperature readings his Madman are reading are simply not possible, physics being what they are.

However, I never realized that they were tapping off the existing sensors, and that makes no sense to me.

In my opinion, a secondary watchdog system (such as Madman) should be entirely seperate. In other words, it should have it's own sensors installed. If you don't, you're not learning anything, you merely have two gauges telling you the same thing.

[Stefan]

Sounds to me like SAC is trying to cut corners and save a few bucks and now they're making excuses. (Just my opinion)

[ricster]

I don't have the Madman system in my Patrol, I have a MGL avionics system. Mine is not as good as a Madman by far as I can only read 2 x EGT temps and 2 CHT ( cylinder head )..... but from what I've seen the water temp sensor for the Madman is a separate unit. They basically cut the top radiator hose and join it with a metal sleeve that has a housing for the temp sensor. This is a completely independent sensor and it not coupled in any way to any other Nissan part.

I can't understand why SAC is saying this.

[davejones]

I've just got my trol back from SAC Centurion and had the Madman system installed.

Everything working fine except for the boost pressure reading - this seems to be a sensor fault. Need to go back to fix this. Although i'm not overly stressed with boost pressure, more EGT, Coolant, and oil pressure (which i must still check is actually displaying correctly).

I wonder if the additional electronics of Tony's patrol is causing this?

[ChristoSlang]

Christo, after numerous discussions with Tony, I know that the temperature readings his Madman are reading are simply not possible, physics being what they are.

My Madman has reported coolant temperatures of up to 118 deg C, and the scary things is that it is perfectly possible to get water that hot in a pressurised system. At 118 deg C the the air-con turns itself off (via the lower of the two senders that screw into the bottom of the radiator) to avoid heating the air that flows into the radiator, and then the temperatures stabilise. One hundred and eighteen is a millimeter or two shy of where the red line starts on the 4.2 diesel motor's temp gauge, and according to Nissan anything under the red is inside the "normal working range"!

The other Patrol forum has lots of heated discussions (pardon the pun!) around that particular factoid...

[Peter Connan]

That's true Christo, but Tony has seen 138

And that without losing any water!

Max temp will depend on the pressure of the system. 118 degrees correspond with 0.9Bar (which is the system pressure of most of our cars), but 138 corresponds to 2.4 Bar (G), which is too high for a vehicle system.