Re: [Amc-list] Harness Wiring Service for 4.0 head EFI installs?

[Frank Swygert <farna@xxxxxxx>]

Either get the custom HESCO harness and alter it (some of the connectors aren't on the harness, factory connectors must be used!) or use the factory harness as is. The HESCO harness is currently listed at $523, and is made for 91-96 models. It requires a 98-99 Jeep coil (different connector) and the CPS wires are at the front for the HESCO relocator kit. 

Just be careful about modifying the factory harness much! Some of the sensors are sensitive to resistance and capacitance changes, so you can't add a lot of wire. 12" or so is about the max (shortening has less effect). Relocating the power distribution center (relays and fuses) under the dash shouldn't affect sensors though. 

With a little care and a clean engine compartment to start with, it's easy to make the factory wiring look very neat. Mark did the best job I've seen! My own installation looks more factory, which means a little less neat than Marks. I was building a true daily driver, not a hobby car though... that's the only defence I have! Maybe I'll clean mine up a bit one day, but without pulling a lot back out and just about starting over, there's not much to be done. 

HESCO's harness is pretty universal, and they allow some extra wire where they can. They eliminate most of the relays. No AC relay, doesn't look like there's a fuel pump relay either. It's a basic get the engine running (racing style) harness, add wiring for AC if needed. The fuel pump can be run on a full 12V all the time, and that's what HESCO does (apparently, not 100% sure!). The ballast resistor cuts voltage to around 9V when cruising to lengthen fuel pump life. Otherwise during low demand it's just circulating fuel through the return line. I don't know if 97+ systems with the fuel pressure regulator in the tank (no return line) have a voltage drop resistor, but I think they do. 


--------------
Date: Sun, 13 Apr 2008 21:50:50 +0000
From: Wrambler242@xxxxxxxxxxx

Yeah, I could build harnesses, but last I knew you could get a generic one from Hesco still.
Somewhere in the $300+ range, but available.
Custom harnesses are too variable to mass produce well.
Some want the ECU hidden some don't

I would not even use most of the factory harness if i was to do it again.
Just the ECU and sensor connectors and build to my taste.
I was chicken when I did the American and thought I would play it safe with the factory harness, but in retrospect I would have moved the ecu and PDC centers back under the dash and cleaned it up even farther.
  
To do things like that one a for sale basis would take a chassis to lay the wiring out in.

-- 
Frank Swygert
Publisher, "American Motors Cars" 
Magazine (AMC)
For all AMC enthusiasts
http://farna.home.att.net/AMC.html
(free download available!)

_______________________________________________
Amc-list mailing list
Amc-list@xxxxxxxxxxxx
http://splatter.wps.com/cgi-bin/mailman/listinfo/amc-list