TheNerd

The below wiring diagram for the ground(s) of a '96 (I believe) Overhead Console show that pins 2 & 4 are both "ground", however they are oddly independent grounds. Does anyone have any insight as to why they used 2 independent grounds for the OHC? I am shoe-horning one into an '87, and plan to splice those together into a single ground (to keep the kick panel connectors down to 2 4-gang weatherpack connectors). Thoughts, concerns, problems?

As a totally lazy guy at heart, it concerns me that Chrystler spent the extra $ and effort to specifically provide 2 independent grounds to the OHC.

tagordon

Some circuits are in a normally open state and some are in a normally closed state. Thus requiring seperate grounds that can be opened and closed independently. So I would suggest keeping with the OEM setup to prevent a potential short circuit.

PS. I know this from working on my bike; a 91 BMW that is Cafe'd, every circuit has its own ground as some r norm' open and some r norm' closed. And yes, I did short out some of the wiring, not fun!!!

TheNerd

I see. Thanks for the info. I guess if you have had bad luck, and Chrysler put in all that effort, I should probably keep them independent. And who cares how clean it looks anyway if it is behind the kick panel right?

blasto9000

It's to provide the same ground reference for the overhead console, instrument cluser and temp sensor. Without the two grounds the temperature readout will probably be erroneous.

This isn't classically a safety issue, but it could turn into one as the body corrodes and alters the ground potential between the driver and the console (e.g. touch a metalized part of the console and get a hit).

TheNerd

Both grounds have been wired independently. One was for the lights, and one was for the computer. While I still do not think it was necessary (as neither are "switched" grounds), it is done and working. Now all I need to do is figure out how to "initialize" or re-set the compass.

Also, the wiring in my '87 is soooo old that the voltage drop from all the interior lights (when the doors are open) causes the incandescent bulbs to be REALLY dim. Anyone know what bulb size is used for the courtesy lights (or will fit 168, 194)? I want to replace them with LEDs and am too lazy to remove the OHC again to pull them out to see. Sylvania lists 6 or so different bulb sizes.