PZJ77 to 1HD-FT - 12v to 24v Electrical Issues (1 Viewer)

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Need some input from people who know more than I do about 24V systems. I have a PZJ77 with 24 volt stock setup. I'm getting a 1HD-FT 24 valve 12 volt engine with an H151 delivered in a few weeks. What sort of electrical compatibility issues am I going to run into?

My initial thought is the PZ is kind of like a shortened HZ. So does it share an alternator and starter from a 1HZ? Keep in mind the PZ has an R series box behind it. And an HDT is sort of like a factory turbo 1HZ (I know, not exactly). Does the evolution of HDT to HD-FT stick with the same starter and alternator setup? Am I going to get lucky and have those parts all just swap over from a 1PZ to a 1HD-FT? Or are 24 volt parts available for an HD-FT? What other issues will I have trying to put a 12 volt motor into a 24 volt truck? What else on the engine is 12 volts versus 24?

Thanks in advance!
 
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You need to find a parts manual and cross reference the part numbers for compatibility. I know the favourite parts diagram is not available in NA but for a swap like that I would get a $70 12 month VPN subscription so I could use the diagrams. It makes life much easier than waiting for someone else to do the legwork.

Or find the parts on ebay with a part number in the blurb and then see what else fits it.
Or check out the diagrams available where on line toyota parts are sold.
 

arnott1t

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fuel cut off solenoid.... that one to look for. Not sure the HD FT has that but on my HDT it was a thing.
 
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I guess my main question is does a 24 volt version of the 1HD-FT exist in any market? If so then parts comparability becomes much easier.
 
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I would probably wait and see what comes with the engine. I think you will be lucky with the starter and alt. Then you would just have the glow system to deal with.
Im not sure about the oil pressure sensor, fuel cut solenoids. Things began to change a bit with the 1HD FT
Most part numbers are on the part itself, then just google it.
 
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It’s coming complete out of an 80 series the owner bought for parts, from what I’m told it’s a 12 volt motor with a 24 volt starter and I have access to the whole truck for whatever I need. I found another thread about a 1HDFT swapped 77 that included a 24 volt glow screen part number. I’ll confess I’m not a late model diesel expert. But I will try to get a hold of the wiring diagrams you’re talking about, those will be helpful.
 
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But I will try to get a hold of the wiring diagrams you’re talking about, those will be helpful.

They will be helpful but I was talking about parts diagrams. The workshop manuals have the electrical schematic included. It should be in the body chassis section. Most Toyotas have an engine manual separate to the other one.
 
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1995. And I have Onur assisting with parts already, I guess I was hoping someone had already done something similar and a list of what does and doesn’t swap over. Even stuff like AC compressor seems like it would be 12/24 volt specific.
 
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My imported FT engine from Japan was from a 24v coaster. The only thing that was 24v was the starter motor, everything else was the standard 12v stuff you find elsewhere.
 
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Thats basically what I was told. 12v motor with 24v starter. The issue is the truck itself is 24v.
 
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The engine will be piece of cake, all the 24v stuff(starter, alternator, and the fuel cut solenoid) from your existing motor/pump with swap right over. It will come with a bunch EGR/emissions BS, get rid of all of it. The engine although newer is just like the older HZ/1HDT, all it needs is power to the solenoid and fuel to run. I swapped my HZJ77 and it was all straight forward.

Your challenge will be the trans, H151 has a bunch of electrical controls to it, which are 12v, so you will need to convert down and figure out how to integrate it with your existing 4wd switches. And it is different length then the R151, so you will need to rework the shifters and crossmember to make it all work. I would consider utilizing your existing R151, the flywheel should swap right over. I am using my original H55 with mine.
 
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The AC compressor is specific on the FT, it is the "long" nose type, but if its include with the engine, you can just swap the top plate off your existing one over where the hoses connect. The clutch is 12v though. What I did was setup a relay, switched by the original 24v clutch signal when you turn your ac on, taking power off a 12v fuse block.

The 12v fuse block is something I setup off a converter to power other 12v needs. I have both a switched and a constant 12v block.
 
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The AC compressor is specific on the FT, it is the "long" nose type, but if its include with the engine, you can just swap the top plate off your existing one over where the hoses connect. The clutch is 12v though. What I did was setup a relay, switched by the original 24v clutch signal when you turn your ac on, taking power off a 12v fuse block.
Weird, mine never came with the a/c compressor only the mounting bracket so I just stuck my old HZ one on and it works perfectly and all the pulleys still lined up. What makes the FT compressor different?
 
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Weird, mine never came with the a/c compressor only the mounting bracket so I just stuck my old HZ one on and it works perfectly and all the pulleys still lined up. What makes the FT compressor different?

Wow really, the FT AC bracket is not in the same location relative to the pulleys as the HZ so the pulley sticks out further on the FT compressor, the two are noticeably different.
 
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Ive come across differences in AC brackets before. Someone sent me some pics of a HZJ7* bracket on an 80 series and it was about 10mm different. I think it was because the 80 series has more room between engine and radiator. Im not sure how the alignment with the pulleys works out.
 
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My FT engine was from a coaster bus not a cruiser so maybe they are slightly different?
That could be if the coasters use a different mounting bracket, which would be cool to confirm, but its probably as hard to find as the long style ac compressor.
 

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