Isuzu Trooper Owners Club UK™

mikevelarde · * Joined: 21 Mar 2013 Posts: 30 Location: Santa Cruz.

trooper's guru. I have my LHD 1999 3.1td check by a friend's garage. it has the sotf system push button on the dash, the trooper already had a digital speedo cluster similar to the 3.0 model. the original speedo gauge was faulty, and i was able to get a 3.0 speedo gauge and fitted into my dash, now all the gauge works except for the tacho(rpm).

now the problem that i encounter with the 4x4 system is when i switch on the ignition, the 4wd character lights up and goes off after the engine starts. but when i press the 4wd button on the dash, nothing happen, no clunk underneath the passenger side, and the small gear stick cannot be move from the 4h position no matter how hard i try to shift it to 4lo , but when my friend's mechanic applied a direct 12v feed to the rear actuator, i get into 4 wheel drive but cant get out unless i applied the 12v power to the actuator again. the mechanic told me the mechnical side of the system is working ok, but i got some electrical issue that he is not able to solve.

trooper's guru please help a newbie here! btw, I was from the Philippines.

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Rhanagar · Posted: Mon Apr 14, 2014 15:15 Post subject:

Sounds like a fuse issue to me on the switch circuit.
_________________
1990 Isuzu Bighorn LWB Mk.I 2.8TD Manual Lotus Edition
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto Lotus Edition

Deceased
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto LS

Rhanagar · Posted: Mon Apr 14, 2014 15:19 Post subject:

Try looking at fuse C-10. Should be a 10 amp fuse.
_________________
1990 Isuzu Bighorn LWB Mk.I 2.8TD Manual Lotus Edition
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto Lotus Edition

Deceased
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto LS

Rhanagar · Posted: Mon Apr 14, 2014 15:20 Post subject:

.. or possibly C-4 (10 amp) which is the fuse for the dash switch.
_________________
1990 Isuzu Bighorn LWB Mk.I 2.8TD Manual Lotus Edition
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto Lotus Edition

Deceased
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto LS

mikevelarde · * Joined: 21 Mar 2013 Posts: 30 Location: Santa Cruz.

Thank you Sir Rhanagar! The fuse box is located at the left side kick panel? Or is it located at the engine bay after the battery tray?

Rhanagar · Posted: Mon Apr 14, 2014 18:26 Post subject:

Either/or/both Smile

Dunno to be honest. I have only worked on the system on a Frontera B series. Should be marked on the fuse box covers, or in the manual. I would say the switch one would be in the car, and the actuator in the engine bay logically. I got those fuse numbers off the wiring diagrams I posted on the first page Wink

_________________
1990 Isuzu Bighorn LWB Mk.I 2.8TD Manual Lotus Edition
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto Lotus Edition

Deceased
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto LS

mikevelarde · * Joined: 21 Mar 2013 Posts: 30 Location: Santa Cruz.

Sir Rhanagar.

I have measure the feed to the switch beside the 4wd gear shift , it is only 3.38 volts regardless I push the 4wd switch on the dash or not.

I know it should be 12 volts going to the switch..... confuse....

mikevelarde · * Joined: 21 Mar 2013 Posts: 30 Location: Santa Cruz.

Guys, I was following the step by step guide of member Rhanagar post about the sotf system.

1. I bought 6 meter of 3mm inside diameter blue silicon hose and replace all the black rubber hose on the sotf system. still no go on the 4wd system.

2. then I try to of get 12 volts from the feed below right side of the rubber gaiter cover , regardless if i press the 4wd switch or not, I consistently get a 3.59 volts from the feed going to the rear actuator sensor/switch, I can barely hear the relay in the 4wd ecu clicking, and the 4wd indicator on the dash is blinking @ 2 hertz/sec.

First, i thought my 4wd ecu is defective, so I order one from Dan Westmorland last April and have it installed, but I still get only 3.59 volts going to the rear actuator sensor/switch,but the relay in the new ecu is clicking louder than my old ecu. and this time the 4wd indicator is blinking faster @ 4hertz / sec. but still no loud clunk below the passenger side seat(right seat)(LHD）

what am i missing there???? please help a newbie in troubleshoot the sotf system!

mikevelarde · * Joined: 21 Mar 2013 Posts: 30 Location: Santa Cruz.

by the way , I have check all the fuse and they appear to be ok.

Gribble · Posted: Mon Jul 07, 2014 7:01 Post subject:

If I read this right you have a 3.0 meter unit in a 3.1 car ? You have checked both fuses that supply the 4wd ECU ? C4 and c10.

The two are the same but there is a small difference on the battery warning light side which may affect the 4wd ECU .

The 12v power for the IGN light and the 4wd light are on the same circuit so that's ok if the battery light goes out.

Is your car a 3.0 that's had a 3.1 put in or all original ?
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2 New Troopers !

Rhanagar · Posted: Mon Jul 07, 2014 7:56 Post subject:

I think its a 1999 Mk.IV 3.0 with a 3.1 put in.

My thinking its a bad earth, or paossibly a fault on the 4wd ECU. Testing the 4wd ECU output would be a good course of action.
_________________
1990 Isuzu Bighorn LWB Mk.I 2.8TD Manual Lotus Edition
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto Lotus Edition

Deceased
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto LS

eithan h · Posted: Mon Jul 07, 2014 9:10 Post subject:

After the ecu it goes through the motor I've had a faulty one before that did similar, change the motor on the back of the gearbox

Gribble · Posted: Mon Jul 07, 2014 9:33 Post subject:

I'm thinking that if the 3.1 alts been wired odd to make it work on the 3.0 loom the 4wd light cant get 12v when the cars running as the blue charge relay turns the earth off for the battery light to go out but on a 3.0 it puts 12v to the light to put it out and the 4wd light and the battery light are on a common feed.

Just thinking it through -

There is a page in the manual that shows how to test the T/box shifter too .
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2 New Troopers !

Rhanagar · Posted: Mon Jul 07, 2014 9:54 Post subject:

Ok so new 4wd ECU and no difference. Direct feed to the gearbox actuator and it shifts.

Not saying anyone is wrong but seeing as its a 3.1 conversion I think Gribble may be right. The alt wiring might be at fault, or an earthing issue somewhere. May even be a broken wire that is shorting out. I would start tracing wires and looking for breaks.
_________________
1990 Isuzu Bighorn LWB Mk.I 2.8TD Manual Lotus Edition
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto Lotus Edition

Deceased
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto LS

mikevelarde · * Joined: 21 Mar 2013 Posts: 30 Location: Santa Cruz.

Sir Gribble, my unit is 1999original MK IV body with original 3.1TD engine in it, in the Philippines, 1999 is the model year change from MK III to MK IV, but 1st half of 1999, we get new body with 3.1TD engine, then 2nd half of 1999, we get new body and 3.0 (4jx1). yes you are correct, I bought a new speedometer cluster from a 4jx1 to replace my original speedo cluster for 4JG2.

I have tried removing the blue charge relay from the fuse box behind the battery, started the engine, and still getting 3.59 volts reading. I never change the wiring behind the alternator. they are all factory fitted.