CDL & 7 Pin mod.

[Olazz]

Started a new thread to clarify this once and for all as Im not experiencing the joys of FULL control of the CD with either of my cruisers.
From a previous post:

This allows full control over the centre diff. Low or high range. Our understanding of the pin 7 mod (well MY understandiing) is that it is something to do with KEEPING those long intervals. There are loads of us here who have unplugged the plug ans stuck in a dash switch. We now have total control over the diffs and ratios. It couldn't be any better. Even if I am wrong about the pin 7 mod, whatever it does do, we don't need it.

It could be that cutting pin 7 is the same as unplugging the plug on the box and in fact it is about achiveing the same thing in a different way. But that is counter to what we believe it to be.

Now this is where I need clarification.
I have a CDL in both my cruisers and have not disconnected the plug to change the gearing on either. A) because one is a manual and B) won't be driving the Auto off road.

However on both trucks just fitting the CDL only allows the CD to be locked in High range and will NOT disconnect the CD in low range as is being suggested.

So the question about the 7 pin mod can't just be to revert to the original change pattern in LR or why do it, as fitting the CDL switch doesn't change the pattern.

If you just unplug the infamous plug,(the one you made up Chris) will this ALSO allow you to switch off the diff lock in LR or just give you different gear change pattern? (it doesn't on the manual BTW; tried that already to see if it would work)

Will the 7 pin mod actually allow you to unlock the CD in LR too?

Does anyones CD actually switch off in LR by just hitting the CDL switch in cab? I'm guessing not.

My understanding therefore is that the 7 pin mod allows one to UNLOCK the CD when in LR as hitting the cdl switch alone does not do this.

Anyone care to educate me?

 

[Garfieldus]

Taken from sleeoffroad.com and tried and tested as being gospel!!!

The purpose of the pin 7 mod is to overide the default behaviour that automatically locks the center diff in low range.

If you do this mod, you are going to need a CDL switch, otherwise you will never be able to lock the center diff.

What you accomplish is you have interrupted the signal from the transfer case that tells the lock ECU that you went to low range but you are still sending a signal to the transmission ECU telling it that you ARE in low range. Therefore the transmission will shift in the correct low range pattern.

In addition you now have true manual control over center diff locking. It only locks when you tell it to without regard to transfer range selection.

If you add a CDL switch you do not have to do the pin 7 mod.

 

[stumog]

i found a post the other day cant remember now. it stated there was a plug under the dash that you pull the pin out of then that allows you to be able to have it in low range and not in diff lock. i want to do it as i have a cdl switch but cannot unlock the diff in lr. which is crap as i had to tow a 110 with a trailer and a disco that was stuck in a gate way. i had to use low but as i was o a hard surface would have liked to not have ghe cdl locked.
i will try to find it on thursday and post a link.
stu

 

[Chris]

I couldn't be much clearer about having full control over the CDL. I can drive in low range with no lockers at all. I push the button, get CDL and keep sensible ratios. I have not done the pin 7 mod. But have unplugged the cheeky connection off the transfer box.

Like I said, the pin 7 mod KEEPS the stupid, or as they call it the correct low range pattern. If you only do the switch and nothing else, it gives you awful low range intervals, but what I can't tell you is if it allows full control of the locker when in low. Why? Because I have never bothered. I just put in the dash switch and unplugged the connector in one move.

 

[Chris]

Now, in the spirit of international friendship, I've been out in'tpissing rain to look at my manual. This is as nature intended. Not messed with. In high, dash switch locks and unlocks CD. In low, it comes in automatically and the switch does nowt. So when it's warm and dry I shall probably unplug something so that it only locks on the switch. Just need to tell the box that it's in high range still. As it's a manual, I control the gears. Mostly.

 

[Olazz]

Right, I have just done the 7 pin mod on my FZ auto. I can confirm that it will allow you drive in Low range without the CD engaged and no ABS disconect.

Pushing the CDL switch on my truck has no effect, so with the pin 7 mod, I cannot lock the CD. This may be a peculiarity on FZ cruisers.

I know for a fact that disconnecting the plug on the manual diesel does not give me full control of the diffs as you state CJ, so don't quite know what you do that's different.

So I'm back to square 1. I will try the plug disconnect to see if I indeed, get FULL control of the CD with the switch.

 

[Gary820]

I'm going to unplug that plug tonight when I'm up at the mancave.
Won't be driving it till the weekend though to check how it drives in lr

 

[karl webster]

Chris is right Lazz.
fit the Cdl switch take the plug off the transfer box and hey presto sorted for manual and auto trucks. Have done it hundreds of times on the whole 80 series range. Are you pulling the correct plug off?

 

[Olazz]

Are you pulling the correct plug off?

I have tried both the plugs on the diesel manual, and no joy with the CDL switch. I haven't yet done the plug on the auto as I don't fancy going to lie in the wet and fiddle. Will try it on weekend.

I now know that the 7 pin mod does NOT help this issue.

 

[karl webster]

There are three plugs under there Lazz.
It will defo work on the manual as well. The plug is situated around 5 past the hour on the top drivers side.

 

[Chris]

Quote - Lazz I know for a fact that disconnecting the plug on the manual diesel does not give me full control of the diffs as you state CJ, so don't quite know what you do that's different. Well the simple answer to that is because I am doing it in an auto. I have never said that this works for a manual. I've never said you get full control in anything other than an auto.

Now, in the spirit of international friendship, I've been out in'tpissing rain to look at my manual. This is as nature intended. Not messed with. In high, dash switch locks and unlocks CD. In low, it comes in automatically and the switch does nowt. So when it's warm and dry I shall probably unplug something so that it only locks on the switch. Just need to tell the box that it's in high range still. As it's a manual, I control the gears. Mostly.

Wehn you go into low, there is a shaft that moves into the extension housing. This trips a simple on off detent ball. If you unplug that, the ECU doesn't know you are in low.

I don't want ABS in low range. I want to be able to lock up actually. Maybe the pin 7 keeps low range ABS. No thanks.

 

[stumog]

which plug is the correct one to pull off the transfer box? does it matter mine doesnt have a vc as its a early one
stu

 

[Chris]

I've got a T box outside. If it's dry tomorrow, I'll take a pick and label up the connectors for you. If it's raining, you can b*****

 

[stumog]

whats the b word you talk about?

 

[Chris]

Shouldn't do Stu.

Connections on the T (auto) box from memory are:
Control wires to CDL itself.
Detent to detect centre is locked
Detent to detect low range engaged
Detent to ...err I have forgotten Going to look at FSM

Damn you Lazz, I've just had to go out in the rain again to look!!! I seem to remember that the manual has one less detent though. So it's auto related.

Edit - it's called the 4WD indicator switch. But no idea what that actually means

 

[Olazz]

Thanks Karl, will see whats what when I get under.

Oh CJ, next time you post and say it works, please be more precise and state "I can only vouch this works for my auto, as I have not carried out the task on my manual yet", there's are good chap.

 

[Chris]

Sorry old bean. I forgot to make allowances for the deficiencies in my audience. Again. Never really considered this on a manual to be fair.

 

[Jon Wildsmith]

On our 80's (including this manual one ) I just disconnected the switch on the transfer box and plugged in the CDL switch on the dash. Then the only way CDL locks is if the dash button is pushed in. If you unplug the wrong connection on the transfer box it's usually the one that detects CDL is locked, so it will seem like CDL isn't locking even when it is ...

 

[uHu]

On the 100, the Low Range detection switch (the one you can pull the plug out of to get CDL-control in LR as well) also controls the Suspension (can stay High at any speed), the ABS (different algoritms) and the engine/ECT.
The pin-7-mod will still give the LR-signal to those three systems, and give full control over the CDL in LR.

Another mod is to allow the RDL in High Range....

 

[Olazz]

On our 80's (including this manual one ) .

Now that's the form JW... CJ could learn a thing or two about concise and clear posting. So it works with the manual as Karl attested too. I'm assuming I disconnected the incorrect two plugs. Couldn't see a 3rd as KW states, but I obviously didn't look hard enough.

Will look under the auto on weekend and hope it works... not that i will need it on the auto, but just want to know it works. Def will get it sorted on the african truck as I would use it often.