hotrodder1143

have a donor truck but need good info for the wiring of it

wyoming9

iTrader: (1)

Pretty simple get the EWD`s( Electrical Wiring Diagrams) for both vehicles .

Then sit down and figure out what you need

hotrodder1143

ok are they relativly easy to find or what cause ive tried to look a little bit. do i have to take the dash out to unhook the harness ?

wyoming9

iTrader: (1)

You really don`t need to it depends just what all you might be doing ??

If you have the complete truck and the Complete wiring harness you might want to swap the cab harness.

It all depends are they both Manual ??

Both Auto ??

Both 4x4 ??

Lots of different things to know and decide then go from there.

Some of the EWD`s can be found online I like having the hard copies I bought a few on Ebay and other places.


easy to take the right seat out and door off gives you lots of room

hotrodder1143

im gonna take the cab harness n all. they are both 4wd and both 5 speeds. im just not that great with wiring. the dash cluster is even the same in both trucks. are the diagrams in the back of the books u can buy at advance ? cause i have those

wyoming9

iTrader: (1)

They can help a little on the major things

Hadmatt54

What wyoming9 is talking about is Toyota Factory Wiring Diagram Manuals. Here is a link to a 87 Truck
The Chilton and Haynes manuals don't give you the detail and don't have the accuracy of the factory manuals. Keep an eye out on amazon and ebay you will eventually find the two years you need at a decent price.

Terrys87

iTrader: (1)

Basically someone tried to take a 90 dash and harness and put it into my 85 truck. It probably could be done but with enough will and determination and I looked into finishing what they started and it was more headache then it was worth. I would suggest find and 87 harness and staying with it. Each year does vary some what and some that is already on the truck you could keep. I am guessing the tail light and fuel harness is probably alright and so is the fuse box under the hood. So you wouldn't need to swap those out. If you was to stick the 90s harness in, you will need to replace every harness in the truck. Here is a thread that I created that has a lot of information that will apply to your truck if you swap with the 84-88 truck. https://www.yotatech.com/forums/f116...4-88-a-278925/ I still need to add some information but it is more complete then what I have found.

Why are you wanting to swap? It is a big job in itself and then trying to make the 90s stuff fit is a whole another issue in itself. The 90s dash is a bit wider and mounting it up is going to require some fabricating or trying to make the cluster and what else fit into your dash is going to be more trouble then it is worth in my opinion. I just recently completed the 22r to 22re conversion and an 85 harness to the 87 since I couldn't find a good harness for my 85. I have done others as well and you really need the entire harness from a complete truck. There are a ton of variances that would take pages to list.

What you are talking about is the reason I came across my 85. They tried the same thing and it got over their head real quick. It was a big mess. It took me awhile to find a good harness and just now got mine running. I would try to fix the harness you got or replace what is needed. The harnesses separate easily and come in 4 sections. Fuel/Tail Light Harness, Injector Harness, Main/Dash Harness and the Headlight Harness.

wyoming9

iTrader: (1)

I was under the impression they were just wanting to swap the wiring harness not the whole dash.

So to not be needing to repin connectors or do all the extra splices.

I could have read it wrong myself.

Terrys87

iTrader: (1)

I seen cab harness and maybe I misunderstood as well and the 87 and 90. The cluster are different. They may connect to the harness but not sure if they would work. Even same year but going from a fuel injected to carb, a friend and me found out that the white wire that basically goes from the alternator to the heater blower is different in the fuse box under the hood.

If am right, the 87 is the only year that has pins in the connectors for the fuel/tail light under the seat. All of the other 80s model in this generation are blade type. A friend of mine is having one heck of a time finding that one harness to get his fuel gauge working. Toyota did some screwy things even between each year. Even for the same year they have several different part number for the Main Harness. I really believe that each option changed the part number.

hotrodder1143

i thank yall for the help but basically i want to put the FI into the 87 n i thought u had to use the majority of the harness to do so. ima keep the whole harness anyways out of the 91. im just tryin to figure out if its eaiser to add the FI parts into my 87 harness or splice the 91 main half of the harness( under hood and cab) into the 87 ??

hotrodder1143

but ima look for those ewd on the web soon

Terrys87

iTrader: (1)

If you are real good at reading wiring diagrams it is possible I suppose. Just doing a straight 87 swap is complicated enough. You are going to have to get a fuel injected tank and add the tail light harness. 91 injectors are different the 87 so it will be a 91 electric truck basically when you get done. I will say that I would want both the 87 and 91 manuals as Toyota is notorious for changing at least one or two wire colors even for the same items like clocks windshield wiper motors ect... Even when you have the same year but two different trucks have different options, that can get confusing as well.

If you are wanting a fuel injected truck, find a complete donor from 85-88 is my suggestion. Even using a two wheel drive truck would be easier then what you are wanting to do.

wyoming9

iTrader: (1)

My head hurts from trying to figure this out.

*** One word of caution these plastic connectors get brittle with age and break easy so be careful disconnecting things

There has to be a bunch of threads on going from carb to fuel injection .

Most important is up grading the fuel system the pump and the rubber fuel lines to handle the higher fuel pressure .

Not forgetting a fuel filter to handle the pressure as well

It would be nice if you posted where you ?? Live in person Help could be close at hand.

hotrodder1143

i live in southpoint ohio so if there is anyone close with greater knowledge then me on this ur more than welcome to come join me and turn some wrenches

wyoming9

iTrader: (1)

Well if I was within a hour or two I would been across the river on I 64 but that was at least 20 years ago.

Blackulua

Ive done it many times.You need swap in the 87 type tps into the 91 throttle bore and get it adjusted properly.The rest is pretty much bolt-on and check for leaks and the ground wires connected.