Just to be sure before I get cut happpy, The 2 brakets Circled in pink need to be cut completely off, right?

Also the air ducting box circled in yellow. I know I have to adapt the back of the 4thgen airducting to the 3rdgens, but do I remove that whole box and adapt it to whatever opening is behind there, or do I leave it on and adapt it to the opening of the box you see in the pic?

Thanks.

 

yes you need to cut the brackets off... and the airbox that is shown on the pic stays like it is.. you will adapt the 4th gen to fit the openings of it.. that is how i did mine and everything works perfect...

 

Thanks man. I did cut the brackets off the other day after I found a post by either you or tpiroc. I put off the A/C ducting till later, but I did find your post that explained how you cut the 4thgen box that should be helpful. Did spend the whole day screwing with the headlight/dimmer switch though. Took me ten minutes to actually cut the wires and match them up and connect them, but the dimmer wouldn;t work. So I spent hours just going over and over my wiring diagrams only to find out I had disconnected a ground wire that bolted to my old dash frame and forgot to hook it back up

How many bolts do you have holding the Dash Itself on? Also if you have fog lights, how did you hook them up? Thanks

 

bolts holding dash in... 5 accross the top.. and the 2 at the steering column.. and it is tight.. yes i have fog lights.. they are hooked up just like factory on a 98.. you have to splice or repin the relay different and then hook into your headlight switch and cluster wireing so that it works like factory ( when hi beams on fog lights off... you know) ill dig up the wireing if you want it... glad to see yours is comming along.. right now i am just working on the door panels and adapting the kick panels and trim from the 4th gen to work in my 91

 

so you do have to tie into the headlights and relay, thats what I thought. If you can find it, please do post the wiring for the fog lights. Thanks!


Edit: Here Ill just post up what I have thought of and if you can compare it to yours and let me know how close or far off I am, that'll be great.


4th pin/color 3rd pin/color

A- Yellow-------------to 3rdgen relay (brown wire)
B- Purple-------------C-Purple
D- Brown-------------to headlight switch (brown wire)
F- Gray----------------B-gray
G- Black---------------Ground



Thanks

 

If you ever find that fog light diagram you used let me know. I tried hooking them up the other day. Before I did hook them up, I was not getting my guage cluster to light up and the dimmer wouldn't work. For some reason when I hooked the fog light switch up, only when I would actually turn the switch on would the dash lights come on and the dimmer would work, but the fog lights wont come on at all.

Also I can't find how my fog light switch is connected to the fog light relay. I tried tracing the wires but non lead from the switch to the relay. According to my Helms wiring manual, My fog light switch SHOULD have 4 wires; ground(black), purple (to fog lights), gray (fuse) and brown( to realy).
However, I only have 2 wires on my actual switch, gray and purple. If anyone could help me out please do before I go nutZ. Thanks

 

So all you have to do is cut the brackets and connect the wiring?

Tazmear
"I wanna do it also"

 

Yeah pretty much. and drill a few new holes in the firewall to connect the new dash because they don't line up with the old holes. But its a real easy job. I got all my wiring worked out now. fog light switch was actually easy once I stopped paying attention to the colors of the wire and more to the function of each wire. Just got to finish lining up the dash, solder the wires together, and cut the top pad and a/c ducts to fit and Ill be set.


just for reference heres how my lights are wired. '95 wireing connectors and cluster and 2002 light, dimmer, and fog switch.

3rd------------function---------------4th

headlights

red -------------------------------------red
orange ---------Tail fuse-------------orange
not used------------------------------red think it was for 4thgen DRL's
green-----int fuse--------------- ----gray
yellow--head dimmer switch-------yellow
black------------------------------------black
brown x2--------marker lights------brown


Dimmer
4th
-green (int fuse) hook to green and gray wire you hooked up for headlights

-gray (dome lights, door lights, courtesy....) hook to white 3rdgen wire

-brown(marker lights) hook to the 3 browns that you already hooked up for the headlights\

-black (ground) hook to the ground from headlights


Fog lights



4th--------------------------------------------3rd

I only had 2 wires on my 3rdgen fog light, brown and purple

a- yellow-------------------------------------purple
b- purple------------------------------------ to the purple and yellow you justed hooked up
d- brown-------------------------------------to brown
f- gray----------------------------------------to gray illumination wires on guage cluster
g- black --------------------------------------to black grounds for head and dimmer

 

Man that will help out big time, what year dash did you use?

Tazmear

 

The dash is from a 2000 Trans am with '95 wiring and guage cluster (also have a 2000 cluster but think its busted) and 2002 Top dash pad, console, A/C, healights, dimmer, fog switch and trunk button.

 

ok im havin trouble...

I hooked my 4th gen green wire onto the green wire on the third gen harness and also tied my gray 4th gen wire on also like the diagram says.

then i cut my gray wire and tried to splice my white third gen wire into it but with my dimmer off it has back light and all the lights come on (head lamp, courtesy etc.) but when I switch it on all go off and nothin works...what did I do wrong? I also have 2 white wires that I have no Idea what they do. I have followed the wiring diagram above and this was the only problem I have...

Help me out!!

 

Did you remember to replace the ground wire that was originally on the old dash brakcet under the steering column. I had just about the same problem till I realized that I forgot to hok it back up.

On the 3rdgen or 4thgen harness?

 

I'll check that tomorrow...

and the whites are on the 4th gen harness on the dimmer..messed around a lil more and got nowhere

Jason

 

The white wires... I didn't have white wires on my dimmer. But I do remember when I first started the swap, I had a bunch of printouts I made from different posts here and elsewhere about the swap. I remember looking at one wireing diagram I had for a 4thgen that had white wires whereas mine had a differnt color for the same function of the whites, but I can't remember which color mine was, right now. Tomorrow Ill have to search the garage and see if I can find the diagram for ya.

 

heres a pic of my headlight switch. the white connector is for the dimmer switch and the black connector is for the headlights themselves.

does this help any?

 

I found some of my papers. The white wires should be the same as the gray wire I have on my 4thgen connector (for dome lights, door lights....) You should have a white wire from the old 3rdgen headlight connector and that is what should hook up to the 4thgen white wires. In case you don't have a white wire on the 3rdgen connector I attached a pic to show you where it was located on the old connector and just take whatever color you have in that location on the connector and hook it to the 4thgen white wires. Hope that solves your problem.

 

ok when everything is hooked up nothin works right, or not at all. the third gen white wire seems like it needs to be grounded. When I put a power to somethin clicks under my hood but when I ground it with say my dk gren wire the dome and courtesy lights work...Did I ground somethin wrong?

Jason

 

Thats weird man. The only thing I can think of is either our cars have the same colored wires but serve different functions or did you ever reconnect that ground wire under the steering column? Because if its not grounded or grounded poorly, all sorts of weird things will happen till it is connected. Also if you don't already have one, get a shop manual or ask someone here for a diagram for your specific car. My shop manual made my wireing VERY easy.

 

john5.7 87Iroc U R DA MAN!!!! I found that missin ground and It was the problem!! Everything works perfect now!! So thank u very much!

Now can someone show me a pic of their ducting! I wanna se how u mated ur 4th gen peice to the 3rd gen piece! I can see kinda how it would go but let me see what others have done

 

Glad I could help. Heres how I did my ducting. came out perfect. https://www.thirdgen.org/techbb2/sho...hreadid=259522 more pics on my cardomain site in sig