Technical Aircon - broken pipe

[minimad99]

re: Air-con faulty [broken pipe?]

Yeah i checked all of them but can't hurt to check again, haven't replaced any just taken out and checked visually. My other thought was relays but i've got no way of testing them.

I'm not working till 1pm tomorrow so i'll take a look in the morning.

 

[Deckchair5]

re: Air-con faulty [broken pipe?]

You don't have any relays in your system on the JTD so that's one problem out of the way

But there are two supply lines to unit N150. A problem in either line will cause non operating fan. Fuse F16 keeps looking at me as a prime target. Check it out tomorrow, make sure there's power output from the downside of both fuses

 

[minimad99]

re: Air-con faulty [broken pipe?]

make sure there's power output from the downside of both fuses

LMFAO, now you've lost me, i was doing so well.
Do you mean the connectors that attach to the underside of the fuse box?
I saw these when i stripped it down earlier.

 

[Deckchair5]

re: Air-con faulty [broken pipe?]

yes, in other words don't just check the fuse is intact, check to see if power is actually going through the fuse

 

[minimad99]

re: Air-con faulty [broken pipe?]

right o, i even get some new fuses just to be sure.

 

[Deckchair5]

re: Air-con faulty [broken pipe?]

Good plan. You're getting good at this

 

[minimad99]

re: Air-con faulty [broken pipe?]

well abit of an update;

all fuses are ok, removed and wire brushed everyone to be sure. checked underneath the fuse box and power is going through them fine I think.

So i disconnected the earth lead for the fan from the battery first, then moved onto the black cable from the fan unit. i cut away a very small bit of insulation on the black cable coming out of fan plug N11, - power there, horray so i know the plug is ok, next

Did the same just prior to the control unit, again, power fine so i know that the black wire from fan to control unit is fine, next

did the same on the second black wire coming out of control unit leading back to battery, nothing, dead so i was thinking the unit was duff until i realised the engine was cold so it wouldn't have switched on yet :bang:

so warmed up engine for a while and tried again, this time when warm and also with aircon switched on i get pulsing light on my screwdriver testing thing which shows that something is passing through the control unit on the earth side but not a constant.

so what does this mean? the pulsing is quite slow probably on and off once second.

i reconnected the earth wire onto the battery terminal and all was the same.

perhaps this will lead in some direction to an answer thanks decks for all your help

 

[Deckchair5]

re: Air-con faulty [broken pipe?]

ok refer to this circuit drawing


Power for the fan is the permanently live feed you found joining the control unit M150 at connector A - you know this is ok i believe

The fan speed control is the one going from M150 to M10 and that's the one you found pulsing. This isn't an earth, it's the control signal from your ECU (M10)telling M150 what to do.

So you need to check the control unit supply line for power which is only live with ignition on. I've marked it on the drawing above

And very importantly as you've had a front ender smash is to check the earth line from the M150 unit to ground. A break in either of these two wires makes the unit non operational

If the earth wire isn't good from M150 to ground (ie zero resistance) then you'll need to renew it or you could piggy back into the original wire and take it to a good earth of your own

If all the supplies and grounds check out then the unit M150 is most likely at fault

 

[minimad99]

re: Air-con faulty [broken pipe?]

Decks,
Thanks for this help, i havn't managed to find the ecu M10 yet, probably been looking straight at it. LOL
I thought the black pulsing wire ran straight to the battery negative terminal, hence thinking it was an earth.
It does go in around the battery and fuse box first though. There are two thin wires at the M150 end that are wrapped into the black and red running into battery area.
I'll have a look at these thin wires as they do split out again under the fuse box. i' guessing for fuse F16.

I'm assuming the small letters without boxes on the diagram are wire colours, but what colour would H & C be?

Just to through something else in the mix, found this on elearn.
"The two-speed electric cooling fans increase the heat dissipation capacity of the radiator and/or air conditioning condenser.
They are controlled directly by the injection control unit in accordance with a specific operating logic Characteristic of working principle 1060 DIESEL FUEL INJECTION."

hmmmm??

 

[Deckchair5]

re: Air-con faulty [broken pipe?]

M10 is your main engine ECU, big jobby with loads of wires but could be located anywhere different than shown on eLearn etc

Wiring codes, make a note of these somewhere as they're the first letter of the colour in Italian

N= BLACK
B= WHITE
C= ORANGE
M= BROWN
A= LIGHT BLUE
S= PINK
V= GREEN
R= RED
Z= PURPLE
G= YELLOW
H= GREY
L= BLUE

They're notorious for being a different colour anyway in real life but black is a fair bet for earth

 

[minimad99]

re: Air-con faulty [broken pipe?]

another update with some progress;

Fuse F6 & F16 are OK, checked the actual fuses and also removed the E & C plugs from underneath the fuse box and both relevant pins have power,
i have also checked the other end of these wires which are also live so i know for definate that the fan control unit m150 on the diagram is getting both a permanent live and and ignition feed live so no problems there.

With regard to the pulsing black wire that i found last time - this is definately the earth, it runs from the M150 right to the battery negative terminal. However today i could not get it to pulse, got nothing at all.

I located the fan speed control wire that is red/yellow as the diagram. This is a much thinner wire than the black one.
This red/yellow wire had no power although i don't know if it should have??? where would the power source come from....... perhaps you could clarify. I've tested it with engine off/on, aircon off/on....nothing.

Now if the fan control unit m150 sends the signal to the ecu then i'm presuming the m150 is knackered but........
if the ecu sends the signal to the M150 then i may have a serious problem if the ecu has issues

There is always a posibility that the earth is still the problem, what's the best way to test it?

cheers

 

[Deckchair5]

re: Air-con faulty [broken pipe?]

Ok we're getting there

Referring to the wiring diag up above
You've tested the 12v direct and constant supply from fuse box E to M150 connector A tested OK

You've tested the Ignition based 12v supply line from C to M150 connector C tested OK

You've tested fan OK wires black and red tested OK

Earth line (black) from M150, ignition off, check for zero resistance between the M150 unit and a good earth spot on the engine OK? If not then trace the black wire through as to where it turns open circuit ie no connection

Now disconnect the control line red/ yellow and test out the M150 unit by connecting that red/yellow wire from M150 to a good earth somewhere. Turn ignition on. Watch your fingers as fan should now work. If not then M150 must be suspected dud.

There's no internal wiring diag for M150 but i suspect it's just a simple internal circuit with a big capacity resistor and heat sink to give the two fan speeds- full speed and half speed

If the fan works when you earth the red/yellow control line then it's time to trace why there's no control line signal coming from M10 (the ECU)

 

[minimad99]

re: Air-con faulty [broken pipe?]

check for zero resistance between the M150 unit and a good earth spot on the engine OK?

Hi Decks,:worship: :worship: :worship: :worship:

this bit has me confused, sorry. I don't have a multimeter only a light up screwdriver with a wire & crocodile clip,LOL

With the c/clip attached to a good earth(engine bolt or similar) and screwdriver touching exposed inners of black m150 wire. If nothing happens ie no light, is this zero resistance?
or as i'm testing and earth does the c/clip need to be attached to a live?

Sorry if this is a really stupid question. :spin:

 

[Deckchair5]

re: Air-con faulty [broken pipe?]

LOL
Get yourself down to Maplins or Halfords and pick up a multi meter, about £5 tops and move into the age of discovery.
I'll be back later tonight for the home electronics course

 

[minimad99]

re: Air-con faulty [broken pipe?]

OK Dad,
You can send me the bill for all your advice when it's fixed,LMFAO................................minimad runs off to local motor factors.

 

[Deckchair5]

re: Air-con faulty [broken pipe?]

Ok I'll send you a pm

 

[Deckchair5]

re: Air-con faulty [broken pipe?]

Drat! Can't send piccies by pm
Here's what I would check and how to connect up your multimeter on that M150 unit

 

[minimad99]

re: Air-con faulty [broken pipe?]

cool,

On the the red/yellow fan control-ECU wire there is a connector block underneath the battery fuse box so i'll use this junction to test tomorrow hopefully.

cheers

 

[minimad99]

re: Air-con faulty [broken pipe?]

update:
earth wire has 0 resistance so all good there ! Also tested the control wire for resistance too and was 0 so i'm assuming this is good LOL

i've tested the control wire by bridging a wire between it and touching an earth as you mentioned decks with ignition on and got nothing so i'm guessing the m150 is up the creek.
I left the connector i mentioned above intact so the 12v ignition feed was still going to the m150 then attached a wire to the control wire by cutting away a bit of insulation and touching the other end to earth.

When playing i accidentally touched my own extra wire against the 12v ignition feed hence earthing that and got a spark blowing fuse F16, doh.
then got " asr failure security failure and loose connection " flashing and it wouldn't turn over.
then started raining so i've had to leave it, bloody weather

I've replaced the fuse and left battery disconnected for 2 hours, all now fine, phew!

have retested the control wire and still no fan activation, had ignition off and on and engine on and off and aircon on and off..........nada

so i think i'm gonna have to search some scrap yards as fiat want about £130 according to eper.

If anyone knows where a scrapped JTD is can they let me know, i would be willing to pay postage or courier

cheers
Neil

 

[Deckchair5]

re: Air-con faulty [broken pipe?]

Yes it sounds as if the M150 unit is gone so that's exactly what i would do, have a look and see if you can get one from scappies and try that by substitution. There's been a few rolled cars on here lately so maybe someone has one up for grabs

Have to be more careful with those live wires and sparks though!