Join Date: Jan 2003
Location: Sherwood Park, Alberta, Canada
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Re: 84 rebuild
Very few have done much with the 1984's as they were a single year electrically and electronically.
From memory John Dodge posted a while back about the wiring swap.
As you probably know the 1984 has the Logic Module in the passengers side kick panel and a Power Module beside the battery, as were all 1984-1987.
1988 went to a SMEC style electronics with a single module beside the battery.
Assuming you remove the 1984 under hood wiring and LM that leaves you with installing the 1988 engine harness.
The actual Engine part is no issue as its the matching Engine but the headlights are the main underhood difference.
The next issue is the bulkhead connector, I know the 1988 goes through a grommet in the firewall and connects with the fuse box.
I'm not sure but I believe the 1984 bulkhead connector is right at the firewall and there is your issue.
I've only done L bodys with a bulkhead connector so when joining it to the SMEC harness I chopped off the Engine side wiring coming out of the bulkhead about 1 ft.
I also chopped off the SMEC harness where it goes through the firewall and spliced them together.
It's not that complicated as most of the wires are for lights, gauges etc.
Alternatively, you could strip the entire harness from the 1984 and replace the Engine, dash and rear body harness with the 1988.
The 1984 and 1988 don't connect at the firewall/bulkhead/fuse box/dash harness is the main issue to consider.
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