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Discussion Starter · #1 ·
Does anyone know if the 88 and 89 Caravan 2.5 non turbo engine compartment wiring harnesses are the same?? Same color coded wires?? I was told by someone the engine compartment wiring harness is different for 1989. Need to know before I start a project. Many Thanks!!
 

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1974 Plymouth Valiant - 2013 Dodge Dart - 2013 Chrysler 300C
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There were some changes. Some of them I could see changing the wires. Not so much the CPU change but maybe... the higher pressure maybe too... not sure.

See Chrysler - Plymouth - Dodge 2.2 and 2.5 liter engines - chronology (at https://www.allpar.com/mopar/22-chronology.html )

A new common block was used for turbo, standard, and 2.5 liter engines; it included stronger main bearing supports and caps, thick cylinder walls, balance shafts (only used on the 2.5 and late turbo 2.2) and cross drilling between the cylinders. Without a lengthened deck, the 2.5 liter engine maintained its displacement with a shortened piston.

Non-turbo engines got a new injector and higher fuel pressure.

The CPU on the SMEC was upgraded again.

“Phase II Quiet Idle,” began, including an acoustic cylinder-head cover (already used on turbos), a change to the tooth style on cam belts (deep rounded teeth), plugs for the timing indicator and probe in 2.5 Turbo I and manual-transmission cars, and a transmission dust cover-to-engine oil pan foam seal on 2.5 Turbo I and manual-transmission cars. Idle quality was improved by cutting valve overlap by 30% (this had already been used on 2.2 Turbo I and II engines in 1988).
 

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Does anyone know if the 88 and 89 Caravan 2.5 non turbo engine compartment wiring harnesses are the same?? Same color coded wires?? I was told by someone the engine compartment wiring harness is different for 1989. Need to know before I start a project. Many Thanks!!
I would not assume they are necessarily the same.
Your best bet would be to have both sets of wiring diagrams on hand.
1989 introduced the electronically controlled 4 speed automatic behind the 3.0. Theoretically that should not affect the 2.5 powered vans, but they could have made changes to all vans for some reason.
 

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Discussion Starter · #4 ·
The 2.5 was powered by the same tranny as the 3.0. Difference is the bellhousing. Awaiting a more definitive answer. I do appreciate the input. Do not have a harness for an 88. I have 89 Parts Manual, but it is 700 miles away!!
 

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. . . Does anyone know if the 88 and 89 Caravan 2.5 non turbo engine compartment wiring harnesses are the same?? Same color coded wires?? I was told by someone the engine compartment wiring harness is different for 1989. Need to know before I start a project. . . . .
From resources that I reviewed I was able to recreate the pinout diagram for a 1988 minivan with 2.5 liter 4 cylinder engine. The engine controller has 2 electrical connectors. The only other resource that I have that is a close representation of the 1989 minivan engine controller is a pinout chart for the 1989 Acclaim Spirit twins which were available with the 2.5 liter 4 cylinder engine.

The only difference I noticed is connector #1 cavities 6 and 46 which have the wired pair for a communication bus connection for the trip computer offered on the 1989 cars. Do not know if that would be a concern for a 1988 minivan configuration which does not show these circuits.

If you do proceed with this swap please post your results for all to read. This will MOST CERTAINLY be an interesting challenge.

SMEC pinouts 1988 minivan 2_5 liter 4 cyl.jpg SMEC pinouts 1989 Acclaim Spirit 2_5 liter 4 cyl.jpg
 

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Discussion Starter · #8 ·
From resources that I reviewed I was able to recreate the pinout diagram for a 1988 minivan with 2.5 liter 4 cylinder engine. The engine controller has 2 electrical connectors. The only other resource that I have that is a close representation of the 1989 minivan engine controller is a pinout chart for the 1989 Acclaim Spirit twins which were available with the 2.5 liter 4 cylinder engine.

The only difference I noticed is connector #1 cavities 6 and 46 which have the wired pair for a communication bus connection for the trip computer offered on the 1989 cars. Do not know if that would be a concern for a 1988 minivan configuration which does not show these circuits.

If you do proceed with this swap please post your results for all to read. This will MOST CERTAINLY be an interesting challenge.

View attachment 27897 View attachment 27901

I appreciate the pin printout for both 88 and 89. Will check the 88 here with 88 Caravan pin printout to see if any differences there. Then, will proceed with caution. Daunting task, indeed!! Will post once completed, but it will take some time. Much Appreciated. Thanks very much.
 

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Discussion Starter · #9 ·
I just was contacted by another person in another group I belong to. He has successfully done a transplant exactly like the one I will be doing. He sez the bulkhead connector pins line up and no further changes/alterations are necessary. Looking forward to doing the transplant!
 

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Discussion Starter · #10 ·
I appreciate all the replies. will examine all of them before I proceed. This info is invaluable. Many Thanks again!!
 
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