4wd relay???

[mvtimmyk]

im sure this has probably been discussed somewhere, but i cant find an answer. 4wd used to work just fine, then when i needed it, nothing happend. i have a basic grasp of how the 4wd system works, and it seems to me the problem might be electrical? when i press the button there is no longer a relay click and the dash light doesn't come on. i am assuming that the problem is in this part of the sequence rather than with solenoid/vacuum etc. i have changed the 4wd ecu and this hasnt helped. could this be a faulty relay and if so where is it? also is there a fuse somewhere that im unaware of? any help would be much appreciated, thanks
tim

[BUSHWHACKER]

Crystal ball is a little cloudy today and I can't see any vehicle details under your username.

[mvtimmyk]

sorry!
LN130, 1993
thanks

[BUSHWHACKER]

OK, check the 'GAUGE' and 'ENGINE' fuses in the fuse box behind the panel next to the accelerator pedal, thats where the 4WD electrics get their power from.

[TonyN]

If you have power as Vince said, next culprit is the solenoid on the back of the T/Case, but check all the vacuum line to the front axle, as if may have not disconnected properly and hanging waiting for something to happen

You only get the dash light once all the parts are engaged and in the right place so its not overly helpful for fault finding.

Best off just working you way through in order.

4wd button contacts ok?, then is solenoid working, is front prop engaged, is ADD engaged,etc...and see where its fallen over.

[mvtimmyk]

a little more help needed please!

firstly thanks for the replies, secondly i apologise for not being as clued up on car mechanics as i wish i was! ive done a bit more diagnosing, so:

in neutral 2wd front prop spins freely
in drive 2wd same
in drive with 4wd button on, no relay click and front prop spins freely
in drive with shift lever in 4L do get a relay click but front prop still spins

fuses are all fine, like i said before have changed ecu, vacuum tubes to front diff seem visually fine but i havent managed to remove them from their solenoids because they seem very stuck on and dont want to risk breaking things unnesssarily. im assuming that as the relay clicks using the 4L lever, the relay is ok.

so im guessing its something on the T/C??? if its the solenoid, would someone mind giving an explanation as to where it is and how to remove it and free it if its stuck. any confirmation on whether i have come to the right conclusion or not! many thanks for your help

[mvtimmyk]

also....

ive just read a post from a few years ago in which someone describes a virtually identical situation as mine and he suggested that it may have been coincidence but it happened when he had the glow plugs changed. thinking about it, mine hasnt worked since my plugs were changed. is there any possible link???

[BUSHWHACKER]

Possibly.
The intake tube on the 2.4 (The part that says EFI TURBO on it) needs to be removed to change the glowplugs.
Small diameter, rubber vacuum pipes are connected to each end of this tube which control the 4WD, check that yours are still attached.

[mvtimmyk]

alas, no

i was so hoping to find those pipes disconnected but sadly they are on! maybe i am just muddying the waters by mentioning the glow plugs (but they were changed between the 4wd working and not). based on what i described earlier, is the T/C solenoid the best place to start? many thanks

[Rockabillygoaty]

Mr Bushwacker sir!
If you remember rightly, I had the same problem on Billytruck!
It worked out that the switch had gone on the transfer knob, and was rectified when i had a new 4wd knob off you!

So perhaps its the same thing with this problem
Ken
The Goat!!

[mvtimmyk]

to bushwacker

just read your post about the switch. i really appreciate your help with this. let me add a little more about the issue. i originally changed the ecu with one i assumed was working, but it made no difference. then when out driving yesterday i was idlely pressing the 4wd switch on/off on /off when ever i was doing slow speeds, when all of a sudden the ecu (which is currently hanging out the dash) kind of sputtered into life, making lots of rapid clicks. i stopped and played a little and eventually 4wd engaged fine. i managed to get it to engage/disengage many times fine and thought that it was randomley now working. now, just as randomley it has stopped working, but the ecu still sometimes makes lots of rapid clicks but without 4wd engaging. my confusion is this: in the brief time it worked, it engaged using both the switch and the lever, now neither works. if the switch was knackered, would 4wd still engage using the lever if the ecu was good? im not sure if ive been sold a dud ecu?

[LemmingLegion]

Well when I got my truck, the 4wd was non-operational.
The first thing I did was to check the switch, it worked, the next thing was to check the front diff, but to make sure I never had the front diff problem, I did the ADD modification. (I have freewheel hubs on mine) Still nothing. So I then checked all vacuum hoses, and the 4wd relay, all good.
So then after I had established the above was all ok, I then stripped the actuator off the T/C, lubed it up put it all back together, and it showed signs of life! (Woohoo I though!)
So I repeated the proceedure, made 100% sure that the gear that pushes the engaging rod into position, was itself correctly positioned, et voila.

No probs since!
Hope that helps, though it's pretty much just a reiteration, as this has been covered extensively on this forum.
Good Luck