Tips Requested for Engine Wiring Harness Removal and Refurbishment - 1994

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A few weeks ago my 94' coasted to a dead stop after blowing the EFI fuse (after going over a bump). After some help from a fellow cruiser head who happened to be driving by we traced it down to a short within the wiring harness, specifically where it routes to the 02 sensors. I was able to drive it home with the 02 sensor harness disconnected but the short itself is further up into the engine harness. I was fortunate enough to drive home 30 miles after messing around with the harness enough to temporarily fix the short.

Unfortunately the engine harness for a 1994 is no longer available new so the next step is to remove it for troubleshooting and repair.

Any tips or suggestions would be helpful. I'll review the FSM and likely take care of some while you are in there items since the intake has to come off.

Thanks in advance!
 
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If you really want to refurbish it, pull the entire thing. Refurbish it all on the bench. Wrap it with fresh wrap of your choice. Repair any damaged or brittle plugs and wires.

You will be good for many more years.

Cheers

Thanks! That's the plan.

I guess specifically I'm asking if anyone has tips on removal and or "while you are in there items". It'll be a good opportunity to access the fuel filter, PHH, hard to reach vacuum and coolant lines, etc.
 

Bludozer

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Thanks! That's the plan.

I guess specifically I'm asking if anyone has tips on removal and or "while you are in there items". It'll be a good opportunity to access the fuel filter, PHH, hard to reach vacuum and coolant lines, etc.
There needs to be some sort of "while you're in there" general type thread where people can post what they have to do and then everyone else can make comments and suggestions costing them large sums of money.

That said in your case take a look at the heater core since you have to take the dash apart anyway.
 
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Having done this some time ago, I found the only problem area to be the DS fender; I removed all the bolted on bits and the harness came away nicely.

There was one connection that had me scratching my head for a minute. There is a ground connection between the inner and outer DS fenders (only this side, not the PS) which requires you to pull the two apart. The ring connector is sandwiched between the two sheet metal corners at the bolt. I had the wheels and running boards off, and pulled the entire outer fender, which probably helped (I don't think this is actually required, but I didn't have to do it the hard way - with everything still on the truck). The bolt is hidden on the inside lowest corner.

Unfortunately, I don't have any photos, but that may at least help you find the bolt. If you can't remove the bolt and pull the wire (there's just the one) up from inside the fender, you'll have to cut it (the wire) as low as you can reach, in order to remove the entire harness, and save enought length to ground it somewhere else.

FWIW, soldering is not recommended in the harness because it's inflexible and breaks after repeated bending/vibration. The wiring harness repair manual (RM1022E is the 1995 version, but it'll work for the 1994 too) requires crimp connections. If you don't have a copy, I highly recommend getting one. I hear they can be had for the asking.

HTH
 

SNLC

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There needs to be some sort of "while you're in there" general type thread where people can post what they have to do and then everyone else can make comments and suggestions costing them large sums of money.

That said in your case take a look at the heater core since you have to take the dash apart anyway.

He doesn’t have to pull the dash if he is just doing engine and trans harness.

Injectors been done recently? Yes do the PHH and a bunch of other stuff.

Cheers
 

Irish Reiver

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What @SNLC says. Remove and refurb on a bench. You can still even get the toyota harness tape. Removal will require the throttle body and upper air intake to come off so you can get to the harness plugs that go back towards the transmission. You also need to remove the glovebox for access to the ecu. The harness will come out fairly easily. Expect to be replacing lots of broken connectors. Pretty sure they are all available from Mr.T
There are tons of WYAIT items, PHH, #1 bypass hose, fuel filter, vacuum lines among a few.
 

Bludozer

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He doesn’t have to pull the dash if he is just doing engine and trans harness.

Injectors been done recently? Yes do the PHH and a bunch of other stuff.

Cheers
I thought the only interior dismantling required for replacing the engine-side wiring harness was to drop the glove box?
That's actually good to hear. Thought it was much more involved than that.
 
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What @SNLC says. Remove and refurb on a bench. You can still even get the toyota harness tape. Removal will require the throttle body and upper air intake to come off so you can get to the harness plugs that go back towards the transmission. You also need to remove the glovebox for access to the ecu. The harness will come out fairly easily. Expect to be replacing lots of broken connectors. Pretty sure they are all available from Mr.T
There are tons of WYAIT items, PHH, #1 bypass hose, fuel filter, vacuum lines among a few.
Any chance you have a P/N for the harness tape? Getting ready to tidy-up my Cruiser harness, and pulling the motor in my '89 pickup... While I'm in there, I might as well re-tape the harness!
Cheers!
 

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