RB30 Patrol won't start

[dom14]

Hey guys,

My RB30 has been giving me trouble again. Started cutting off while driving.
Now it can't be started at all.
I had a look and pretty much immediately realized it's an electrical issue.
It's dual fuel. won't start on both.
Basically, electricity isn't getting into the fuel system.
If I give a direct connection to petrol solenoid it fills up the carby and starts without issues.
I'm pretty sure it's the same with the LPG, even though I didn't do it.
I had close look all this late arvo, but couldn't find any broken wires or weak earth points.
Checked all the fuses. They are fine.
So, I reckon it's either an earth issue or major wire is broken or corroded somewhere in the fuel system.
It has an immobilizer, which is working ok. Not sure if it has anything to do with this.
Basically, no problem with engine cranking and other electrics like lights, etc.

I know with a reasonable gut feeling, it's electrical. But, I somehow thought it belongs in the engine thread section.
So, pardon me if I posted the thread in the wrong section.

What is the best way to find the culprit?
Any tips, leads, advice will be gratefully appreciated.

Thanks guys.

[mudnut]

One of the first things in
the system that
is common to both fuels is
the selector switch on the
dash. Make sure there is
power to that. And check
that the lugs or connector
screws are tight.

[dom14]

Ok, cool. I'll go and check it now. I initially thought it's a faulty selector switch. So, I bypassed the switch with crock clip wire connector.

[dom14]

One of the first things in
the system that
is common to both fuels is
the selector switch on the
dash. Make sure there is
power to that. And check
that the lugs or connector
screws are tight.

I found the middle wire of the selector switch is hanging with the connector end not connected to any wire.

There's no doubt that's a problem.

The LPG dashboard gauge has three male sockets(pins). But, only two of them are connected. So, I thought the middle wire of the
selector switch came out of it. So, I connected it, but still no change.

I gave some 12V to that middle pin/wire of the selector switch via the fusebox.

The LPG solenoid clicked, which is a good sign.

Still no idea where the electrical disconnection or the earth problem is.

I'll post some picture of the gauge and selector tomorrow.

In the meantime, I'm wondering whether the middle wire of the selector suppose to connect to the one of the pins on the gauge!!!

I couldn't find any other wire or connector hiding under the dashboard for the middle wire of the LPG selector to connect to.

I have no doubts it's obviously disconnected, it's that I'm not sure it's the only problem.

[mudnut]

My computer screen is shot
so I can't view the pictures
properly.
I reckon Yendor is the man
to talk to dom.

[dom14]

My computer screen is shot
so I can't view the pictures
properly.
I reckon Yendor is the man
to talk to dom.

Yeah mate. I don't have Rodney's number. But, I know he will reply straightaway if he sees this thread.

I reckon I posted this on the wrong section. It should be auto elec section.

I posted this thread in patrol4x4 forum auto elec section anyway. I reckon, Rodney will see it soon.

I'm not totally hopeless. I worked out how to get the fourby going. But, I would have to find the location of the wiring issue for my own good.
Bypassing the +12V to the fuel selector switch directly from the battery does the trick, as far as getting fourby started.
But, I need to find the real culprit before it catches fire somewhere in the electrical system. :D

Thanks mate.

[dom14]

When I gave the direct +12V from battery to the fuel selector switch's middle pin, all goes fine.

My logic says that this is kinda confirmation that this issue isn't caused by weak or broken earth connection. But, that's my logic and it can be flawed.

Assuming it is +12V supply connection breakage to the fuel selection switch, I need to find where the breakage is. Under the dashboard it is quite a mess. I'm still trying to get the part of the dashboard out, where the stereo system, LPG switch & few other switches fit on to. It's stubborn and won't come out. I can't see any screws holding it. But, I can see the need of pulling it out to have a gook look inside to see if there's any wire breakage or corrosion.

Another thing I've been wondering is whether this has anything to do with the faulty key barrel electrical contacts. But, then again, other electrics, accessories, etc etc are working fine, as far as I can see. I'm hoping the actual wire breakage/corrosion is inside the engine bay wire harnesses, rather than inside the dashboard. Inside dashboard jobs are PITA.

[Bloodyaussie]

My computer screen is shot
so I can't view the pictures
properly.
I reckon Yendor is the man
to talk to dom.

On what your laptop???/? or home pC

[dom14]

http://www.apexus.com.au/document/gauges/ga100.pdf

Following the above diagram of a standard LPG gauge(like the one I have on my RB30 Patrol), I'm now fairly certain that the LPG/Petrol selector switch +12V connection, comes from the LPG gauge. So the blue wire is +12V connection(which we already know) and the blue wire connects to the LPG gauge +12V pin/male socket. Now, assuming this is the way my LPG system is wired, it's kinda certain that the sender unit on the LPG tank has either a corroded connection or the +12V connection to the sender unit is broken/corroded somewhere between the battery and the LPG sender unit. That's a whole lot of wire length to check. So, I reckon I back track from the LPG gauge and see where the connections go and look out for breakages/corrosion, etc.

[dom14]

My computer screen is shot
so I can't view the pictures
properly.
I reckon Yendor is the man
to talk to dom.

I fix computers. So, if you're nearby, let me know. If it is fixable, I can fix it for nothing.
I'm in Eastern suburbs(Melbourne of course)

[dom14]

My computer screen is shot
so I can't view the pictures
properly.
I reckon Yendor is the man
to talk to dom.

You gave me a damn good tip to get started anyway. I was stuffing around under the bonnet when you tipped me to check the fuel selector switch. I got on the right track from there.
Thanks for that mate.

[mudnut]

I fix computers. So, if you're nearby, let me know. If it is fixable, I can fix it for nothing.
I'm in Eastern suburbs(Melbourne of course)

I'm only 360 or so k's away. :)
It's the screen onmy laptop BA.

I was expecting to get my better
half's old work computer to replace
this one, but that has fallen through.
I've had a reasonable quote to get
another screen supplied and fitted.

There are four screws inside the top
of the air vents that need to be
taken out to take the centre section
of the dash on a GQ.

[dom14]

I'm only 360 or so k's away. :)
It's the screen onmy laptop BA.

I was expecting to get my better
half's old work computer to replace
this one, but that has fallen through.
I've had a reasonable quote to get
another screen supplied and fitted.

There are four screws inside the top
of the air vents that need to be
taken out to take the centre section
of the dash on a GQ.

Ok, cool. 360k is flying distance for me. :)
I thought those four screws are holding the vent grills, 'cos it moves with whole centre section, so I didn't bother to undo the screws.
I'll get to it first thing tomorrow morning.

BTW, if you get a good deal for the screen replacement, then it's ok.
Make sure you compare the cost of the screen with the cost of a new laptop.

If it's not an issue with too many dead pixels, half of the time, it's usually fixable with bit of fiddling & precision soldering.

[mudnut]

I could fix this old thing
3 times over before I
could get even an entry
level device.
This is a commercial
series computer that has
a few extra inbuilt ports and
features, so I will keep it
going.

All of the problems on my
mate's lpg vehicle turned out
to be badly crimped lugs.
There are some really dodgy
gas conversion mobs around.

[dom14]

I could fix this old thing
3 times over before I
could get even an entry
level device.
This is a commercial
series computer that has
a few extra inbuilt ports and
features, so I will keep it
going.

All of the problems on my
mate's lpg vehicle turned out
to be badly crimped lugs.
There are some really dodgy
gas conversion mobs around.

Mine has gone through some 'amazing' auto electrical work and LPG electric work.
When I first got it, the LPG safety switch was wired wrong.
Battery to the alternator +12V was connected via a skinny wire(instead of thick 60A) and 20A fuse was attached using sticky tape to the
middle of the wire. No idea what happened to the original wiring and the reason for replacing with cheap and dangerous wiring.
No doubt, my Patrol needs a complete electrical wiring check up.

[mudnut]

I was waiting for you to say that.
A soldering Iron, a couple of bags
of good lugs, a pair of ratchet
crimpers and some TLC is what
the wiring needs, by the looks
of it.

[dom14]

I'm making a homemade contact cleaner using isopropyl alcohol+distilled water.
I like using petrol for cleaning oily+grimy things, but prefer not to use it on electrical contacts of a car for obvious reasons.
Lot of wire brushing and replacing bad lugs work for me today and tomorrow and hopefully not for the rest of the week. After 20+ years, I think it's reasonable to accept that some of the electrical wiring can
deteriorate and corode. What I can't forgive is that a previous owner doing dangerously cheap electrical wiring on the Patrol.
Even the LPG conversion doesn't look like a professional job. This was the time when a compliance plate was not required in Victoria.
No flexi pipes in LPG plumbing, which is ok, 'cos I don't think they existed in early nineties.
But, the wiring it terrible. positive wires from under the bonnet to the LPG tank goes as wires(no harnesses) by simply tie wrapping them to
the LPG pipes.
I just decided to replace all the wiring with new ones and wire harnesses.
So, apparently there's a bit of money to spend for my own good and I need a quick visit to Jaycar electronics.

[mudnut]

No worries, just take your
time and never cut your
wires too short as it is
easier to fix a stuff-up
by cutting and re-lugging
than having to join wires.

[dom14]

Yep. Thanks for all the valuable tips mate.
And if you need any help with computer stuff, do let me know.
This forum has given me a lot. So, I'm more than happy to give back.
Cheers:xxxx::beer:

[dom14]

Eureka! I found it!!!: :bananadancing:

All the problems(well....not all of them) were caused by a hidden fuse. Contrary to what I believed from what I saw, there was so much hidden under a thick layer
of insulation tape. Not one, I found two hidden fuses. Second one is a redundant one, completely hidden under sticky tape.
I'll post the pictures soon.
Contrary to what I saw in the outside LPG wiring(which was pretty bad), the fuses were wired properly(but hidden) with fuse holders.
Contrary to what I posted above about the LPG gauge getting powered first and then passing the +12V to the fuel selector switch.
It's the other way around.

Above diagram of the LPG gauge indicated it correctly, I simply read it wrong.

The reason I misjudged it(where the +12V power get to the LPG gauge & Fuel selector switch) because that quite a few of wire connections were hidden under a thick layer of insulation tape behind the Fuel selector switch.
The power(+12V) to the fuel selector switch was wired directly from the accessory line of the key barrel.
Then a 10A fuse is wired to it(hidden under the dashboard, but not covered with insulation tape), then another 10A fuse just behind the Fuel selector switch.
No idea about the reason for adding a redundant fuse and then completely hiding it with a thick layer of insulation tape.
I'll post the pictures shortly.
Now, I need to find out the reason for the fuse to blow up.
There's a very good reason for that.
I'm still going ahead with replacing all the wires and connectors of the outside LPG wiring.
It's shockingly cheap and sloppy work. Some wires were simply joined and sticky taped.
I'll post the pictures shortly.

The +12V connection(The blue wire in the above pictures) was disconnected from some previous fiddling I was doing.
I think that caused me to misunderstand the whole thing, 'cos the blue wire's(+12V) disconnection from the Fuel gauge has nothing to do
with the LPG selector not getting +12V. Totally separate issues.

[mudnut]

Well, done, dom. Glad you've
found something at last.
Good luck with the rewiring
job. You will be able to
have confidence in the
vehicle when the job is
done to your satisfaction.

[dom14]

Well, done, dom. Glad you've
found something at last.
Good luck with the rewiring
job. You will be able to
have confidence in the
vehicle when the job is
done to your satisfaction.

Absolutely. Now, I have some confidence with electrical related breakdowns, even if it happens in the future when I'm
in the middle of nowhere.
I wouldn't have been able to do it without the help of you guys.
A single sentence of a tip saved me days of fiddling.
I'm just editing the pictures to upload them, so you can have a better picture of what I've been doing, and
hopefully it will help another bloke with the same or similar situation.

[dom14]

These are the photos of my 'discovery', of the real culprit.

What prevented me from seeing these in the first place was that the dashboard center part was covering up all the hidden electrical wiring and fuses.