I have a 1986 Berlinetta is not getting any electrical power whatsoever. I've checked to make sure all grounds are in place, battery posts are getting good conduction. The "Bat" and "tach" are connected in the correct posts on the coil, and as far as I can tell the only thing not plugged in still is the oil pressure relay on the motor. The car has had some modification, here's what it is:

I've removed the ECM, The 305 is gone out of it, replaced with a 1975 2 Bolt 350 out of a Truck, a Non CC Q-jet and Coil-on-top HEI distributor with a vaccum port. I'm trying to clone this car to a V8 sport coupe. I had a 1984 camaro SC I removed the wiring harness from. Both what was in the car and Engine bay. All the gauges worked before I removed it out of the 84. (even with the ECM removed) I took the in-cabin wiring harness out of the 86 Berli, and put in the 84's in-cabin wiring harness and installed the 84's dash with the cable speedometer and analog gauges. Starter is hooked up correctly (I"ve checked it three times) It still has the Berlinetta's Engine bay harness, but the ECM has been removed. Basically, I have an 84 in-cabin wiring harness, 84's Steering column, taillights, and dash with gauges. The 86's Engine bay Harness. My theory is that the firewall plugs between 84 and 86 (especally between Berlinetta and sport coupe) have different # of pins and the pins go to different fuctions within the cabin from the engine bay. I have the 84's wiring diagram, but I dont have one for the 86 berlinetta, just an 86 sport coupe, so I can't verify if my theory is right. It just seems odd that i"m not getting ANY power to ANYTHING. not even a glitch. How far off am I with my theory? Any ideas?

Everything is also connected within the cabin (I.E, headlight switch, steering column, all fuses have been checked multiple times to make sure they're installed and not blown, all wires that plug to grounds, to the fuse box, etc...)

 

I made a very similar conversion myself in the past - but I didn't run into your problems !! The car was an 85 Berlinetta and I replaced the interior with one from an 86 Z28. Both cars were carbureted V8's making the conversion much easier than if the donor was a TPI or a MPFI.

First of all - Here's what you are looking for:




This image is from the 84 Shop manual but I checked the 85 shop manual and the C100 connector is the same. I can only assume that nuthin' changed in 86 and have never run into that in my experience.

If the Berlinetta was an automatic than you are going to loose the automatic tranny plug by removing the ECM harness from the car. If the car was a standard than you will loose the back-up lights. (but it Can't be a standard if it was a V8 Berlinetta !! )

Your theory is right about the compatibility - but in a VERY limited way. As far as the C100 connector; the only difference I can remember from my analog conversion project was the windshield wiper wiring. I had to run the wiring through the firewall from the engine bay to the dash harness to make the wipers work right. You will also not be using the 2 wire connector for the electric speedo sending unit since you need the cable to run your speedo.

My best advise is to start right at the battery with a voltmeter and work your way into the interior checked everything along the way. Be sure that the little ground wire coming off the negative battery cable is connected to the body ( right next to the battery ) with a VERY clean connection - I can't tell you how many times that little wire has caused some of my cars to completely die !!! Also be sure that you installed a braided ground strap from the engine block to the body ( usually done at the back of the block to the firewall. )

Once that's done and the battery cables are connected correctly check the battery for voltage from post to post. Then check battery voltage from the starter to the neg battery post. Then check the thin positive wire leading to the alternator and the Neg battery post. Then re-check those 2 positive connections using the body as a ground.... then re-check then using the Engine as a ground. If you don't have battery voltage at each of those tests than your bug is limited to the battery cables or the 2 small wires coming off the battery cables. ( one pos to the alt and one neg to the body. ) If you do have power everywhere under the hood than starte probing those power wires on the interior side of the firewall. You will already have verified that the body is a good ground source - so use the body when probing the RED and PINK wires on the interior side of the C100 connector.

If those checks pass testing than use the engine for a ground and start probing all the positive leads to the C100 connector (engine side). Be sure to probe all the PINK and RED wires..... ( I can't remember if the Purple -starter interlock - wire will have power going to it.. the ignition may need to be turned to "START" before it gets battery voltage ! )

I would think that even if there was a problem with the ignition box on the column or the neutral safety switch on the shifter that you should still have power to all the cars lights and some of the accessories ( dome light, power seat, door locks, hatch motor, ect.)

My guess is that the small wire leading from the neg battery cable to the body is the problem. My Step father got stranded this spring after taking his Bird out for it's first ride of the season becasue of that wire..... He called me saying " Everything just died !! " I showed up - scraped the body and the wire with a screwdriver, screwed the wire back in place on the body and made him buy me a 6-pack when the car started !!!



Good luck !!

 

This is actually the same wiring diagram I was following for the 84....If theres not really a difference, then theoretically it should all work. Intresting to Know about the tranmission plug....I seem to remember removing a 4 or 5 prong plug off the shifter when I removed the ECM, but eventually, I"ll be stealing the 5 speed out of my 85 Z/28 for this car.

I'll check elsewhere for bad or missed grounds/connections.

 

Found the problem..................the positive lead from the battery cable wasn't connected on the Alternator tightly and probably wasn't making good contact.........

its always the little stuff that gets ya.........

Now just to do a little creative splicing to the transmission plug, and I'll be able to start her and move her around!