[mytqik]

I am I the process of converting my GU Ti TB45 auto over to a TD42 auto. There is a link in my signature to my build thread for more information on the mechanical side of things.

Everything below is to suit a 1994 black top GQ TD42 into a 1998 GU Ti TB45. Please double check everything before following my lead

As I do the wiring I thought I would document it, save anyone else the hours that I have trawled over GQ & GU wiring diagrams.

Starter:
The heavy Black/red (50mm2) main power cable can be re-used. I re-lugged it to suit my new battery terminals better.
The White/red (6mm2) wire will need to have the blade plug cut off the end and a ring crimped on.

Alternator:
The alternator and P/S pump are on different sides from the TB to the TD, therefore the TB wiring will need to be extended to suit.
I used my old 50mm2 winch power cable in place of the *********** cable that runs from the ALT to the fuse box.
The black wire needs to be extended with a ring crimped on the end.
I found that the plug for the yellow/red & yellow/black is actually the same plug/pin outs as the TD42 alt, so I just extended these 2 wires and re-used the TB45 plug.

 

[mytqik]

Air Con:
I bolted the TB45 A/C compressor onto the TD block.

If you strip the wiring harness apart and back to the firewall the yellow/black is long enough to reach the other side, re-plug into the TB45 A/C compressor - Done!

Water Temp:
I cut the TB45 plug off (should have a light green/black and black wire now), and used the TD42 plug with black & blue/red wires.
The black gets spliced onto the black into plug, and the Light Green/Black splices into the Blue/Red.

 

[mytqik]

Fuel Solenoid:
There are a few options here, but after looking at the wiring diagram I settled on the power to the distributor. This is switched with ign, is also on during start, and has its own fuse. The distributor should have an 8 pin grey plug on it, the power is the heavy solid blue wire. This is really long, so strip it out of the harness and route it to the other side of the engine and down to the fuel pump. Splice it into the brown (with pink band) that feeds into the fuel solenoid.

 

[mytqik]

Throttle Position Sensor:
Since both my GU and my donor GQ where auto's I was lucky enough to have the TPS on the fuel pump.
Matt at UFI did a great job of pulling the TPS off my 10mm pump and grafting it onto my DC3 11mm pump.

There are 2x 3 pin plugs on the TB45, one for the throttle position sensor and one for throttle position sensor and one for throttle position switch. On the TD42 this is combined into 1x 6pin plug.
(I had to find a French copy of the GQ manual before I could find a wiring diagram for a TD42 auto!!)

Throttle Position Switch:
TB45..................Function..........TD42
Green/Orange.....12V power.......Green/Red
White/Green........Full Throttle....Green/Black
Black..................Idle................Light Green

Throttle Position Sensor
Orange...............12V power.......Yellow
White..................Position..........Yellow/Red
Black..................Earth..............Yellow/Blue

 

[Wellsy]

Awesome work buddy!
I have a mate who is looking into doing such a conversion now, this will be a huge help for us!
Thanks

 

[mytqik]

No dramas Wellsy, i have only a few more wires to run and I can start it

It wouldn't take me very long now I know which wires are required!!!

 

[gqpatrol15]

I've literally just got home from picking my gu 4.5 up and will be tackling this conversion as my poor old gq has cancer.

Sorry if ive missed it but are you using the gq td42 wiring loom or splicing into the gu tb45 loom? This thread will really help thanks heaps mate.

 

[mytqik]

I am using the TB45 wiring loom, cutting off the plugs and using the plugs from TD42 loom where necessary.

 

[xhxrsix]

Good job mate! I'm halfway through mine at the moment and this will make it a little easier!

Did you source a GU TD air con bracket?

 

[mytqik]

Hi Guys,

I have a bunch of photos to show the various plugs etc, I will post them in the next day or so.

xhxrsix, I just used the GQ TD bracket and bolted the TB45 compressor onto it. Everything seemed to line up ok. I can take some photos if you like?

 

[xhxrsix]

Ok thats awesome, I have a GQ bracket but haven't had a close look at it, if it bolts straight up that will save me some hassle.

 

[outback]

I removed the TB45 ECU and harness and did it properly

 

[mytqik]

I have every intention on removing my ECU eventually, I need the Patrol back on the road so I am taking the easier option.

Outback, did you cut the ECU plugs off and splice the wires together, or run all new wires?

 

[mytqik]

Throttle Position Sensor:
Since both my GU and my donor GQ where auto's I was lucky enough to have the TPS on the fuel pump.
Matt at UFI did a great job of pulling the TPS off my 10mm pump and grafting it onto my DC3 11mm pump.

There are 2x 3 pin plugs on the TB45, one for the throttle position sensor and one for throttle position sensor and one for throttle position switch. On the TD42 this is combined into 1x 6pin plug.
(I had to find a French copy of the GQ manual before I could find a wiring diagram for a TD42 auto!!)

Throttle Position Switch:
TB45..................Function..........TD42
Green/Orange.....12V power.......Green/Red
White/Green........Full Throttle....Green/Black
Black..................Idle................Light Green

Throttle Position Sensor
Orange...............12V power.......Yellow
White..................Position..........Yellow/Red
Black..................Earth..............Yellow/Blue

I made typo in the Throttle Position Switch:
Red/blue.............Idle.................Light Green

Here is a photo:

 

[Reuben]

Nice work mate! The time and efforts much appreciated!

 

[mytqik]

Oil Switch:
The TB45 dash only has a low pressure light, but the TD42 has a oil pressure sender and switch. At this stage I am only using the low pressure switch, until I work out where to mount a oil pressure gauge (already have 3 on the pillar).
The yellow/blue from the TB45 harness needs to be joined to the green on the TD42 plug.

The other wire in the TD42 plug is yellow/blue which is the oil pressure sender.

 

[xhxrsix]

Hey mate, I have mine running and driving, a few things to sort out still but its getting there.

I have the aircon plugged in but the pump doesn't kick in when the button is pressed. I've tried giving the pump power and it works properly and gets cold quickly.. I'm wondering if i've cut the wrong wire or it needs something else as its a TI with climate control? (also converted to manual now). Any ideas?

Also my aircon pump/bracket was different. I used the GQ bracket and cut 9mm off the mounting surface to move the pump back in line, and will need to make to small right angled brackets for underneath.

 

[mytqik]

I have the aircon plugged in but the pump doesn't kick in when the button is pressed. I've tried giving the pump power and it works properly and gets cold quickly.. I'm wondering if i've cut the wrong wire or it needs something else as its a TI with climate control? (also converted to manual now). Any ideas?

Hey Mate,
Did you completely remove the TB45 ECU or did you just wire up enough to get the TD42 going?

If you did just enough to get the TD42 going, and still have the TB45 ECU wired in, I think the drama is the AC relay. The ECU actually pulls the relay closed and if its not receiving the "check" run signal from the distributor it wont close the relay (It also wont close the fuel pump relay either as a safety feature).

Here is a copy of the wiring diagram for the Ti auto climate control, I have highlighted the wires in yellow. I believe that if you cut these 2 wires and join them (bypassing the ECU) it *should* work!

 

[xhxrsix]

Tried it last night and it works perfectly mate! Thank you! No dodgy wiring needed haha.
Another piece of the puzzle completed.

 

[mytqik]

Tried it last night and it works perfectly mate! Thank you! No dodgy wiring needed haha.
Another piece of the puzzle completed.

Hey Mate, that is awesome to hear, glad I could help

Out of interest did you get your tacho to work?

How did you do your glow plug circuit?
I am about to post up how I did mine, I used as many of the GQ components as I could, the GU even has all the same mounting holes as the GQ for the relay and fusable link!