Ok so i'm getting ready to swap out this 305 tpi and throw it in my rs for alittle while. I currently have a 2.8 v6 in it at the moment.

So to the 305tpi. I did the usual ,

Pulled out all a/c stuff
Drained all fluids
Pulled radiator
Pulled d/s
dropped torque arm

Then went to the computer. Disconnected the wires from the computer, feeded them up into the bay from inside the inner fender. So now i have them in the bay. Isn't this harness just for the engine or does it go through out the whole car?? Cause I tracked it down and it looks like it goes behind the engine and then up to the far driver side corner of the engine bay and then into the car. please tell me i dont have to tare my dash apart etc to get all these wires. This would **** me off if it was all 1 harness.

 

engien harness goes through the fender on pass side. THe wires you're probably looking at are for the blower motor/hvac controls & the vacuum hose for the slider. I'm doing basically the same swap w/an 87 carb 305 using 84 harness.

 

It also goes across and goes back through the driver's side firewall. You can unbolt the inside and outside harness's, it's only one side that's engine related.


Kevin D.

 

Yeah i finally found a thread i was searching for like an hour. It says theres a bolt right on the driver side where the other part of the harness plugs in. Just undo that small bolt and it shall unplug? I wouldn't mind if i had to switch everything over in the bay cause this has wires for 2 horns, 2 fog lights, and i like it better lol.

 

crazy3rdgen,
You should take the dash harness and the remainder of the engine compartment harness out of the 305 car and set it in a safe place. JUST IN CASE!

I swapped an '86 (CCC-Q-Jet) harness into my son's '82 (CFI). Once complete we had a nightmare of a time making stuff work/figuring out why it didn't. In the end, we ended up replacing the ENTIRE car's harness. There were MANY signficant differences behind the dash. Several folks had indicated that the harness behind the dash was going to be fine.... IT WAS MOST DEFINATELY NOT COMPATIBLE.

I'm not an electrician, nor am I one of the most knowledgeable members of the TGO boards. However, I'm willing to bet that going from V-6 to V-8 TBI is going to produce some of the same difficulties.

Inside the engine compartment there are basically four (4) wiring strands;
1. ECM Strand (You've apparently pulled that)
2. Lighting Strand (Small strand on the driver's Side)
3. Power Strand (Big Strand on the Driver's Side)
(alt, starter, dizzy, oil press, temp, wipers, etc.)
4. A/C & Heater (Very small encircles the A/C area enters the car behind Cylinder #8. Gets power from #3)

Sincerely,
Kurt

 

well i'm 2.8 FI and I was told nothing inside my dash needs to be changed. Just swap v8 computer and the 305 tpi harness which plugs right into the v8 computer and then into the driver side in the bay where theres the little nut through the connector.

How should I pull this motor? like where do I attach the chains onto. It's all ready to be pulled. Pretty sure everythings un attached

 

crazy3rdgen,
I was told the SAME thing.... Play it safe...Grab it ALL!!
The harness from the pass. side (ECM) does NOT go through the wall at the driver's side. There is a location or two where the harnesses from the ECM and the Driver's side DO connect to each other. I think that's like one or two quick connect fittings.

The large bundle that connects to the firewall on the Driver's side is in fact TWO seperate strands. There may be a plastic cover over them that makes it difficult to see that they're are two strands. BETWEEN the two strands is a very small (1/4"?) bolt head. It's probably about 1-1/2" long as it goes all the way inside it'll take several turns to loosen it up. Once loose give a LITTLE!!! tug and the entire unit will disconnect.

There should be a lifting ring on the rear of the intake? and perhaps one on the front. At least that's what I had on the 305 and the 350. I'm not sure about the V-6. Pick a couple stout bolts and lift away. I try to use something that's into the block or the head that is of significant size.

Sincerely,
Kurt

 

I agree with Kurt, pull the whole dash harness and also the gauge cluster, the V6 tach will be way off, plus the oil pressure gauge will read wrong as well. There are differences between the dash harness' from different years, so to be on the safe side, swap it all out. I have a '91 T/A dash harness from an L98 car, and it is totally different than the dash harness in my '87 GTA, which was different than the dash harness in my '86 V6 Firebird.

 

ok, So i dont have to physically get inside the car and do anything, Yous are just referring to the harnesses in the bay right? So i'll use both. I wonder if the fuel lines hook up and all. Everything probably has to be changed whata pita

 

crazy3rdgen,

The good news.... YOU HAVE A DONOR CAR!

The bad news... We are referring to the ENTIRE harness. That is ALL of the strands in the Engine Compartment (4) AND the strand that is behind your DASH. It runs from the Driver's Firewall to your fuse box around your steering column and across to your ECM/Computer. YES it is a MAJOR MAJOR PITA. There is a SEMI-EASY way to do this that I learned about from Five7Kid after I had accomplished it the hard way.

SEMI-EASY WAY. Pull the entire dash & Harness as 1 unit.
(1) Remove all the panels under the dash on both sides
(2) Remove the dash pad.
(3) Disconnect the pigtail from the firewall.
Once you have removed the double-strand from the driver's side engine compartment firewall you can remove two small nuts and the pigtail connection can be pushed into the car.
(4) Disconnect the connectors that attach the Dash harness to the rear lighting (behind the Driver's Left Kick Panel)
(5) Disconnect and Remove Radio
(6) Disconnect and Remove A/C control panel
(7) Disconnect wires to center console items
Shift Indicator Lamp, Neutral/Park Switch, Hatch Release, etc.
(8) Disconnect ALL connectors from the steering column (6?)
(9) Remove bolts holding steering column up (4) and let it down on the floor.
(10) Remove ALL the bolts (mostly 9/32") holding the dash into the car.
(11) Double-Check WE haven't forgotten ANYTHING...
(12) PULL THE ENTIRE DASH OUT OF THE DONOR CAR!

You have a donor car..... If you decide to test your luck with the current dash harness go for it....... Don't Junk the Donor until you are sure that EVERYTHING works. I strongly suspect your going to have trouble. As Klortho said in his post, your guages (Oil, Tach) are definately NOT going to be correct for a 305. I am quite certain those are the OBVIOUS differences.....

If you were trying to go to a very basic set-up (i.e. Non CCC-Carb, Vac Advance Dizzy, No Pollution Control, No Computer) you MIGHT be fine by replacing the instrument cluster and hacking up the stock harness to make the basic stuff work. But.... You're going TPI.. you need the Computer and ALL the wiring functioning 100%.

Just my personal opinions
Kurt

PHOTO: The easy way should look something like this......

 

Been there done that~!

 

Same here Kurt

 

uhmm i'm not going there . Lets see, swap over my gauges, swap the engine bay harness. and that sounds good to me. Not going to think of pulling my dash out. I'm just going to plug all the wires in from the engine bay when the motors in, start the car up and see what I got. See how the gauges look and stuff. If the motor runs fine then good. I'll try switching to the v8 gauges if mine arent compatible. We'll just have to see

 

^^ I'm w/all teh stupids that swapped dash harness's too. Only part that really sucked was putting the dash back up. But then I was doing it by myself.

 

crazy3rdgen,

Sort of a final note before I head off for a weekend at the beach......

I did what you are planning... NOTHING worked! Because the "Mapping" of the wires from the engine bay to the interior harness was different. A couple fuses blew instantly and absolutely NOTHING... in the dash worked. The ALDL was wired totally different, there was no Choke Relay etc. etc.

AGAIN: Try your plan, maybe you get lucky. The worst that could happen is probably a couple popped fuses and a bunch of stuff that doesn't work BUT do not toss ANYTHING from your donor vehicle until you are sure! Pulling the dash harness and placing into your vehicle is basically a one full day project.

Good luck!
Kurt

 

As long as I get the motor running for a few days i'll be alright, and then if the dash harness is messed up .. well, you know what i'll have to do . Didn't expect this. So without even touching the dash harness, the motor will still run correct

 

It may, it may not. Injector plugs are different between years, my '86 V6 car had the injector wires going through the C207 connector on the passenger side, where my '87 TPI dash harness has a totally seperate plug for the injectors. My '91 TPI dash harness has the fuel pump wire coming in through the bulkhead connector where my '87 TPI dash harness has it coming from the passenger side connector.

Be safe and save yourself a major headache, swap out the dash harness.

 

1 cars an 89 and the other an 88