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Madd Tyte JDM yo ®
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Discussion Starter · #1 · (Edited)
well, im transferrng over the jza70 fuse box into the ma70. i started to remove all the alternator wiring from the clip and transfer it over to the ma70. then i started to remove basically the whole ma70 fuse box and plugged in the jza70 fuse box. all the connectors are the same. for the RTR plug on the fuse box, i removed the Red-green wire from the 1j fuse box, and inserted the red-green wire from the ma70 car. there is an 18ga white/black wire that leads to a chassis ground right under the 1jz fuse box, thats the only wire i had to cut since i couldnt pry apart the multi-wire ring terminal. all i did was remove that white/black pin from the 1jz fuse box plug and insert the ma70 white/black wire that leads to this chassis ground.

this 1jz has no aux AC fans or ABS, so there are no fuses for them in the jza70 box. but when i removed the ma70 box, i removed the power supply for these fuses since they were spliced from the white cables stemming from the 100A alt fuse. from the ma70 harness, there are the 2 power wires that lead from the fuse box to the body harness, i simply transferred them from the ma70 fuse box into the jza70 fuse box. these terminals are labled ABS and ACS. these 2 wires are now plugged into the 1jz fuse box but have no power supply coming to them, they will be left fallow.

JZA70
I started out on the clip, untaping the entire front engine room harness to separate the alternator wires and thermistor wires. i basically ended up removing the jza70 box and the transferrable wires. i removed the alternator junction block that bolts to the fender. one wire goes across the rad support. the other wire splits and goes into the cabin to a junction block. i clipped this wire. i will be soldering this wire to the associated wire on the ma70. i traced the black alternator cable across the rad support to the fuse box. when it nears the box, it splits into several wires and feeds various fuses. i traced where the white wires went after they left these fuses. they went to other pins on the box, one stray wire went to a plug. check it here;



also, before i was able to remove the 1jz fuse box, i had to remove the Red-green wire stemming from the RTR fuse. when i put this in the MA70, i remove the same wire from the ma70 box and put it into the 1jz fuse box.

i was also able to remove the entire EA2 harness w/o havng to cut ANY wires except the Black/yellow and Yellow/green alternator wires. these wires have to be cut since they go along the engine room harness into the cabin. the easiest way is to cut and solder the EA2 alt wires to the ma70 room harness. the hydrofan thermistor harness will come out of the engine room harness as one piece, just cut the tape and remove the loom. there is one ground wire that has to either be cut and soldered, Or de-pinned and have the MA70 ground pin transplanted into this plug. see the lower corner of the above picture w/ the inset window. remove this ground wire from the ma70 fuse box plug, then insert it into the EA2 harness plug at the bottom of the jza70 fuse box.

MA70
removing the ma70 fuse box starts out like this. a good deal of the plugs just come right out and plug directly into the jza70 box w/o incident. i annotated what i recall having to do to the ma70 box and getting it ready to come out.
i removed the MA70 fuse box and transferred over the plugs into the jza70 box. to remove the ma70 box, i had to trace out the alterantor wires and battery wires. the black wires are alternator, in the "middle" of the wires is the fuse. on the other side of the fuse are white wires, which go to the battery Pos term. all the white wires remove easily. the black alternator wires remove easily except one, where it goes into the engine room harness and then back into the cabin. this has to be cut in order to remove the ma70 alt fuse block. Here is what i had after removing the alternator wires, fuse block and battery terminal wires.

see the pic below w/ the inset window to see where i cut the 2nd alternator wire. from there, i will lengthen and solder the corresponding alt cable from the 1jz alt harness and connect it to the ma70 alt cable to feed power back into the MA70 cabin.


After i got the MA70 alternator power distrubution setup removed, i also removed the C1 harness and associated plugs and wires. Everything came right out w/ only 2 real items of attention. one was the 18ga ground wire that leads to the chassis ground and the other was the AC temp switch no.2, which was the Blue/white wire on C1, slot 6. the ground wire was removed when i de-pinned the fuse box plug in the lower corner of this image

the other wire, AC temp switch No2, is the only other wire that joins C1 to the MA70 Engine room harness. this pin comes right out. i havent yet figured out where to insert this pin. i know this wire comes from the 7MGTE sensors, thru the engine harness, thru C1 and then into the cabin. im not sure how to connect this to the JZA70 wires to retain its function... i have a feeling it may not be needed since it only seems to control the Aux AC fans on the MA70 car.

EA2 and 1jz box into MA70

the jza70 box is now in the ma70 car. the 1jz 100A alt fuse block is transferred over with it. the vacant slot on the RTR fuse block from the jza70 is now occupied by the Red-Green wire that was removed from the MA70 RTR fuse block. now that the jza70 100A alt fuse block and associated alt and batt wires are transferred into the ma70, the stray 12v white wire should then be transplanted into the MA70 square plug that remained in the car. the ma70 square plug w/ 2 pink wires and a looped Red wire has this slot vacant already. the 12v+ jza70 power wire will snap right into this slot of this plug. this square plug serves to send power to the headlight retractor motor wiring. the EA2 harness occupies the rectangular slot adjacent to the square plug. since the 18ga ground wire was removed from this plug to pull it from the jza70 car, the corresponding ground wire that remained in the ma70 car will now snap into this slot. see this pic or the top pic for the plugs in question


now that the EA2 plugs into the transferred jza70 box and the ma70 chassis ground pin is inserted into this plug, there are only a few details left to address. one is to connect the jza70 alternator wires to the ma70 alt wires that lead into the cabin.



the full EA2 harness should now sit in the ma70 and be fully connected to the jza70 fuse block. the only things not connected yet will be the hydrofan thermistor (which will plug into the 1jz rad), alternator power cable junction block (Which will be connected when the motor drops in and engine harness is installed), AC relay (4 pin square plug) and AC junction (8 pin rectangular w/ 4 wires stemming from AC relay plug and EA2).

the only things i have not figured out, and am looking for help with;
-can the 4 pin plug mentioned above, stemming from the EA2 plug directly into the MA70 AC relay?
-what do i do w/ the 8 pin AC junction, with 2 wires stemming from AC relay and 2 from EA2?
-Will i need to splice anything into the AC thermoswitch No2 pin?
++Edit, i looked at the MA70 TEWD, the Blue/white wire that comes from Pin 6 in the C1 conector looks to be a path to ground (Switched by the Thermoswitch on the 7MGTE thermostat housing). when the switch closes, it provides a path to ground for the AC fan 1 and AC fan 2. since the jza70 fuse box has no power for these fans, and the 1jz has no thermoswitch, this wire is unsuable. it will simply be taped up to the harness.
 

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I'll nevAr go single!
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:wtflol:


:1poke:


I'm glad I paid money for my jumper harness, no need for fuse box replacment either.

GL with that....... :p
 

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Madd Tyte JDM yo ®
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7,014 Posts
Discussion Starter · #3 ·
yeah, thanks bro... i figured, the fewer solder joints, the safer my install. im trying to keep as much oem quality as possible.

maybe im just weird. i could have just cut the C1 and D connector and spliced it to the EA2... but i wanted to see what this whole 'fuse box swap' was all about. i remember a few guys saying it could be done and it was "easy".
 

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I'll nevAr go single!
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994 Posts
Hey, its all good. If it's the route you wanna take and you know what your doing, then thats great. I just wouldnt know where to begin with something like that myself.
 

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Madd Tyte JDM yo ®
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7,014 Posts
Discussion Starter · #5 ·
for sure... i like a good challenge. i think itll be an improvment in quality over my last 1jz swap where i did the cutting and splicing w/ an adaptor harness like yourself. i think this way will help me keep things tidy and original appearing. i think the greatest compliment i can get is the lack of compliments because it looks TOO stock. if it turns out good enough to be mistaken for Toyota quality, ill be happy.
 
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lol your making this way to hard!

1st yes use the Jspec fuse box i did there is some things better about it newer and cleaner then my 87 n/a box and it uses a fuse box instead of a lower amperage fusable link for the alternator.

2nd there was only a couple things to splice use all of the ma70 fuse block connectors except the 2F 8 wire connector

the 2F8 wire goes to a ground and to you EA2 connector and some of the EA2 wires from your alternator go to your ma70 body the yellow/green one to be exact.
simple split your ground wire the goes to the chassie under your fuse block 1 ground wire comes from the fuse block the other goes to your EA2 connector or some thing re join the ground wire split rings with the jspec 2F8 wire going to your EA2 then thats pretty much it you had to splice 2 alternator wires i think and that was it but remember my harness was verry clean because i deleted the relays and relay circiuts for the electric fan and the clutch magnet relays since my permacool fan didnt need a relay because my thermal switch was a permacool one also and i didnt need a relay unless i ran 2 fans (overkill) to my switch

no ac relay because my ac system is gone!

3rd i spliced the fuse going to my CDS FAN [20amp now] wire to my perma cool fan the perma cool fan uses 10 amps and pulls 3000cfm since i used the 1jz radiator shroud and i wired the ground side of the permicool to the sensor switch on the radiator hose the switch goes to ground and works great!

Bonus information free of charge here to on your swap!
i pulled the thick black pair of alternator wires through my main engine harness and it fallowed the EA2 wire route into the body of the car i put the old black connector that enclosed the terminal back on it and mounted it on my intake manifold by the tps using the 10mm bolt then i took the old MA70 connector that had a pair of thick wires that went to the old ma70 alternator and shaved the wings off it and rounded the inside of the hole a little bigger and connected it directly to the JZA70 connecotr mounted on the plenum by the 10 mm it looks clean and is factory and that was one of the dumb things i fixed that the JZA70 was poorly disigned for this swap.

POOR things in the JZA70 design for a swap into a MA70 is

robbing the water pump to add another P/S pump on the back of it to pump a hydrofan
fixed by using 2jz waterhousing with permicool hi cfm electric fan

alternator wires come out in the wrong spot so routed them through the engine and come out with the ea2 by the fuse block

P/S line is all screwed up facing wrong way routed from oposit side

used the hydro fan hydralic cooler for the powersteering cooler flipped it over so openings are facing p/s pump using custom brackets used the hydro fan pressure line as the pressure line for the power steering pump.
 

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Madd Tyte JDM yo ®
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7,014 Posts
Discussion Starter · #7 ·
Youre preaching to the choire. i did this swap almost 2 years ago. the first swap i did was to cut the EA2 going to the 1jz fuse box and solder it to the C1 and D connector so the 1jz can talk to the 7M fuse box. i think Hams said he just swapped the fuse box. i decided to try this route out because he said it was easier. its a little more work, but in the end, i have less solder joints and less connectors and jumper harnesses and such.

like i said, i didnt have to really cut any wires except the 2 alt wires. those are getting soldered to the half of the EA2 harness that leads into the fuse box. the ground wire that youre speaking of, was just de-pinned from the 7M box and tranferred into the 1jz box so i dont have to cut and solder it it fits like factory.

the big black altenrator wires w/ the black plastic junction block you speak of, is going to be bolted down in the same location on the ma70 so it looks lke a jza70 under the hood. when you look under the hood of this car, it will look like a USDM JZA70, youd never know it was a swap.

also, the PS line, i had a custom line made for $12 using the original 1jz line. instead of having 7 feet that goes under the motor and then back to the ps rack. i took the PS pump fitting and first section of soft hose and cut it there. then i had the banjo fitting cut off the end that used to go to the PS rack. my hydraulic hose guy got me a crimp fitting for the hose, brazed the original banjo fitting to it and then he crimped this new hose end onto the end of the stock section of soft hose. so the hose is going to connect to the PS pump, loop back towards the firewall and then connect to the rack w/ the stock banjo bolt pointed 180* out of its original position.

im also keeping AC on this swap. its a nice luxury because supras are real street cars and should have AC. plus, itll add to the factory-original quality appearance.

the 1jz doesnt have stupid features. they have features that facilitated production and made working on it simpler in japan with no consideration for people like US who may want to import these cars and swap the powerplants into our usdm cars. if i was engineering the JZA, i wouldnt have bothered to take steps to make it easier to swap this motor into another car. thatd be the last thing on my mind.

the alternator power cable setup makes engine/harness installation easier at the factory.

the PS line has to be that way for RHD cars since the JZ's have the pump on the opposite side of the rack.

the easiest way to add an auxillary hydraulic pump w/o trying to fit a 5th accessory to the clusterfuck was to integrated it into the water pump. the hydraulic fan is the quietest fan offered from an OEM and pulls 2600CFM and is variable. back in 1990, the JZA70 was abused around an open track for hours with no overheating issues thanks to this fan. the hydro fan helps add to the factory quality appearance that im going for.

the PS cooler and hydrofan cooler unbolt from the clip and transfer right onto the ma70 if you enlarge the pass-thru hole on the rad support under the passenger headlight. it bolts down just like stock too. no need to flip or bend or reroute or anything.

i like all the little "pain in the ass", "poor" differences in the jza70 over the ma70. everything that was changed from the ma70 to the jza70 is what makes it a better design. if the ma70 was that great of a design, they wouldnt have bothered to change it in 1990... and we wouldnt bother trying to swap it into our "inferior" ma70 cars.

Evilempire1.3JZ-GTE said:
lol your making this way to hard!

1st yes use the Jspec fuse box i did there is some things better about it newer and cleaner then my 87 n/a box and it uses a fuse box instead of a lower amperage fusable link for the alternator.

2nd there was only a couple things to splice use all of the ma70 fuse block connectors except the 2F 8 wire connector

the 2F8 wire goes to a ground and to you EA2 connector and some of the EA2 wires from your alternator go to your ma70 body the yellow/green one to be exact.
simple split your ground wire the goes to the chassie under your fuse block 1 ground wire comes from the fuse block the other goes to your EA2 connector or some thing re join the ground wire split rings with the jspec 2F8 wire going to your EA2 then thats pretty much it you had to splice 2 alternator wires i think and that was it but remember my harness was verry clean because i deleted the relays and relay circiuts for the electric fan and the clutch magnet relays since my permacool fan didnt need a relay because my thermal switch was a permacool one also and i didnt need a relay unless i ran 2 fans (overkill) to my switch

no ac relay because my ac system is gone!

3rd i spliced the fuse going to my CDS FAN [20amp now] wire to my perma cool fan the perma cool fan uses 10 amps and pulls 3000cfm since i used the 1jz radiator shroud and i wired the ground side of the permicool to the sensor switch on the radiator hose the switch goes to ground and works great!

Bonus information free of charge here to on your swap!
i pulled the thick black pair of alternator wires through my main engine harness and it fallowed the EA2 wire route into the body of the car i put the old black connector that enclosed the terminal back on it and mounted it on my intake manifold by the tps using the 10mm bolt then i took the old MA70 connector that had a pair of thick wires that went to the old ma70 alternator and shaved the wings off it and rounded the inside of the hole a little bigger and connected it directly to the JZA70 connecotr mounted on the plenum by the 10 mm it looks clean and is factory and that was one of the dumb things i fixed that the JZA70 was poorly disigned for this swap.

POOR things in the JZA70 design for a swap into a MA70 is

robbing the water pump to add another P/S pump on the back of it to pump a hydrofan
fixed by using 2jz waterhousing with permicool hi cfm electric fan

alternator wires come out in the wrong spot so routed them through the engine and come out with the ea2 by the fuse block

P/S line is all screwed up facing wrong way routed from oposit side

used the hydro fan hydralic cooler for the powersteering cooler flipped it over so openings are facing p/s pump using custom brackets used the hydro fan pressure line as the pressure line for the power steering pump.
 

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Flea420 said:
:wtflol:


:1poke:


I'm glad I paid money for my jumper harness, no need for fuse box replacment either.

GL with that....... :p
Where did you get a jumper harness? Thanks.
 

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Madd Tyte JDM yo ®
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7,014 Posts
Discussion Starter · #9 ·
i dont think you can Buy one. you just have make your own, or cut the connectors off the jza70 clip and the 7mgte harness, then send it out to someone, like me, who will solder them together and make the jumper harness for you to plug-n-play.... for a small fee
 

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Madd Tyte JDM yo ®
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7,014 Posts
Discussion Starter · #11 ·
ah, touche... there are going to be 2 alternator wires that require soldering and the main alternator power cable that needs soldered to the one that goes into the passenger cabin.
 

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hEY GUYS... Im doing a 1JZ swap im my MA70.. i have done everything.. the engine is in and now im stuck on wirring.. i want to know.. if i swap over the complete engine bay loom from a JZA70 do i still need to do this ALTERNATOR mod?
 
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