Wiring guru's...Help..Pictures..

[Wile E]

I had planned on using the harness out of a '78 Ekly. It is in very nice condition, not all cut up and had power windows which I added to my '79 Malibu. My original harness is a little rough. I've got most of the Elky harness figured out until I got to the instument panel plug. The wire colors and locations between the two plugs ( the '78 and mine) do not match up. I think the Elky may have had gauges, my 'Bu did not. Do I need to cut up & try to re-wire the plug? I have a gauge cluster I could use, I just did not plan on it. Also look at the picture of the thing I'm holding. Not sure what that is. It's from the '78. Some kind of relay?
The plug on the left is from the '78 Elky, mine is on the right. I checked the tech section, maybe I missed this.

 

[ScotSea]

The plug on the left is for the round style guage dash pod. It even has the white wire for the tach in it. I am not sure about the one on the right.

I have never looked at one for the sweep style speedo. Was your original speedometer the sweep style? Now is a good time to change to the round style, as your dash plug is all ready to go.

Notice that all the wiring colors line up for a round style dash, except that you have no CEL in your 78.

Actual data from a Dash

Pin - Cir Num Wire Color Signal

01 - Blank None None
02 - 31 Light Brown (Tan) Oil Pressure Gauge
03 - 35 Dark Green Temperature Gauge
04 - 30 Pink Fuel Gauge
05 - 8 Gray Dash Lights
06 - 14 Light Blue (Pass thru) LH Turn
07 - Blank None None
08 - 15 Dark Blue (Pass thru) RH Turn
09 - 150 Black Ground

10 - 489 Yellow (Pass thru) CEL (Ground to illuminate)
11 - Pink, Black stripe Power side of CEL
12 - 11 Light Green Bright (High Beam)
13 - 237 Yellow Fasten Belts
14 - 931 Green, White stripe Choke light
15 - 33 Brn w/White (Pass thru) Brake light
16 - 39 Pink, Black stripe Ignition - switched
17 - 121 White Tach
18 - 40 Orange Battery for clock (only)

 

[StreetBu]

You dont need to cut anything, but spend about 4 hours pulling your hair out with two wiring diagrams :lol: Pull all the wires out of your connector and put them back in the proper place in the connector. Sounds easy, but the wire colors are somewhat different between the years. Good luck

 

[Wile E]

Yeah, that year difference had me concerned. Looks like I may be better off just switching to the round speedo set-up just to simplify things. Still not sure what that cardboard-wrapped thing is that I'm holding in the picture. Looks like some kind of relay, I have a '79 Factory wiring manual, but that relay thing is not pictured. Must be a '78 year thingy. Thanks ScotSea for identifying those wires, yes mine was originally the sweep style that I had planned on re-using-the plug on the left-

 

[Doober]

I'd say it's definitely worth looking into the round gauge setup, especially if you already have one.

I'd be interested in knowing what the cardboard-wrapped thing is myself, if I remember to, I'll look for it in the harness of my '78. Buzzer maybe?

 

[Wile E]

I think I found the buzzer thing. Could it be a horn relay? I don't know what a '78 horn relay looks llike.

 

[t5montecarlo]

The plug at the left of the picture looks like a PC drive power plug.

My first thought is it was the heater fan resistor, but the 4-lead PC-style plug has me stumped.

 

[Doober]

I was thinking the same thing about it being a molex connector, but the wiring looks almost original to me.

 

[gman415]

Power window relay?

 

[Wile E]

I don't think 1978 has a relay for the power windows, not sure on the other years. This harness has the power window "hot" going from the fuse box direct to the switches and it looks like all factory wiring.