Help, failed Referee smog check for year swap!

[Natedog]

So I plugged the bulb in and plugged the two big wiring plugs and speedo cable back in and turned the key to run position and CEL does not light up. Turned the key to cranking position and the engine starts, no CEL came on at any time. Also I see that their is an 'emissions' light that I've NEVER (since day one brand spankin new from the dealer) seen come on and all the bulbs look good??!??

 

[bobbywalter]

sometimes its easiest to run the cel right from the eec plug to the other side of the bulb, the dash side should have key on power. i dont know exactly what you swapped so theres no way to tell, unless you know for sure that it was the original calibration computer that went with your donor harness setup.

 

[Natedog]

The tan/red stripe wire goes from the #17 pin on the EEC-IV in both 1987 and 1988 according to www.alldata.com wiring diagrams.....

EDIT: Looked again and the 1987 shows this wires goes to the self test connector....1988 diagram shows that this wire goes to the self test connector and then a pink/light greeen wire goes from there to the instrument cluster....

 

[bobbywalter]

yeah my main truck is an 88 and is pink/lg...but some are a different color.

its simple. just take your time on the gaskets...its tight and a pia with these lil 6 cyl.

 

[Natedog]

Late and I'm so tired that I can barely stay awake tonight. Double checked all my wiring diagrams and it looks like I need to add the wire from the tan/red stripe wire (originates at terminal #17 on the EEC-IV and goes to the self test connector plug)...the additional wire needs to connect this tan/red stripe wire to the 'check engine light' according to my alldata diagram.

WTF is the difference between the 'check engine light' and the 'emmisions light'??? It seems they are the same light but different name???

EDIT: Bobbywalter thanks for the help and I used my 87 wiring harness and modified it to be an 88....lol...all the 88 manual tranny harness at the junkyard were hacked to s*** by lazy idiots with wire cutters.

yeah my main truck is an 88 and is pink/lg...but some are a different color...

At least that part agrees with my 88 diagram from alldata....

 

[MAKG]

I should have popped in earlier with my experience wiring a 1987 cluster for a functional check engine light. Sorry.

Someone at Ford had a brain fart in 1986; I don't know if it applies to 1987 or not. The 1986 factory electrical diagram interchanged the self-test input and output labels. STO is exactly equivalent to the ground side of the check engine light, and you can run a wire to it (easiest access is at the PCM connector). They have the SAME color code (what idiot did that?)! STO is the one that runs to the doghouse test connector; STI goes to the single-wire connector. Test it with an ohmmeter before you go splicing.

And if I remember right, it was tan/red. Pink/LG was hot-in-run power.

 

[Natedog]

STO (and MIL what is that?) for 87 AND 88 shows as tan/red stripe wire for both years according to alldata diagrams and runs from terminal #17 on the EEC to the self-test connector (the larger dog house shaped plug under the hood)...but in 88 it then runs from the self-test connector to the instrument cluster with a pink/light green stripe wire.

In 88 the other side of the 'check engine light' goes to the ignition switch, but it doesn't say what color wire.......

 

[MAKG]

MIL is the modern name for a check engine light, since modern vehicles have the computer controlling more than just the engine. "Malfunction Indicator Lamp."

The hot side of the CEL should just be already connected to the power bus on the back of the instrument cluster. Along with all the other lamps in it (including the illumination lamps).

 

[Natedog]

...The hot side of the CEL should just be already connected to the power bus on the back of the instrument cluster. Along with all the other lamps in it (including the illumination lamps).

Yes it is already there.

EDIT: Ah now I see the Malfunction Indicator Light designation on the diagram!

You probably guessed that I'm not the best at wiring diagrams. Thank you for helping! I only have until the end of this month to fix and pass this BS....arrgh. I'm on my last registration extension....and may not be able to get to the referee by the end of the month due to my work schedule.....

EDIT: Just remembered that I disabled the seatbelt buzzer years ago by unplugging it, but don't think that should affect any of this.

 

[MAKG]

Where in CA are you anyway?

It looks like I may be going back down to Palmdale for a couple of days around 15 May. No idea if there will be time....

 

[Natedog]

Sacramento CA.....Palmdale is near Victorville IIRC....will you be coming through this area?

 

[MAKG]

No, not through Sacramento.

Palmdale is closer to LA than Victorville....

Icky BIG desert suburb.

 

[Natedog]

Ahhh, ok I was ballpark....lol. Wish these alldata wiring diagrams would print out with the year, make, model and diagram label on them....gettin tired of hand writing it all on each and every page.

 

[Natedog]

OK, went to local junior college and they did a full check up on the engine and it seems that it runs pretty good and that the smog tech allowed the engine to cool off too much! After they checked it all out and said that only thing is my cat is a little on the week side, but should be ok.

Then they ran it on the dyno and it passed easily with about 450ppm NOx instead of like 1200ppm.

Teacher said that the 'check engine' light is the one to wire in...not the 'emission' light....that is on a timer from the EEC.

Went to wreckers today and got some wires with the correct contact end for the instrument cluster plugs. Using dvm/ohm meter to make sure I'm wiring it up correctly.

 

[Natedog]

yeah my main truck is an 88 and is pink/lg...but some are a different color...

Got my pink/light green wire from an 88 bronco II today. FYI it is tan/red at pin # 17 on the EEC and somewhere in hte engine harness (IIRC near the driver's side firewall) it turns to the pink/light green.