88-94 to 95-98 All Swap Info Compile

[BigBody90]

What year truck would I need to get a drac out of to do a conversion from a 90 to a 96 style. Some forums say that 90-91 had a drac and 92-95 had a vssb, I'm pretty sure my 90 does not have a drac.

[chevyz71man]

92-95 had a drac

[BigBody90]

alright, I got the drac. Do I need to put the dip switch in?

[MStefak]

So you NEED a drac if I'm gunna do the cluster swap in my 88 ?

[MStefak]

As well today I began the cluster wiring harness making. I have the connector from the 88-92 style now i need the 95 up style to mate them together. After i get thsi one to work ill do one for the 92-94 style.

[BigBody90]

If you can note what colors go where from the drac that would be awsome.

[MStefak]

Well guys here the fun begins I have both half the harnesses now its time to connect them. Project2005 how did you tell where to count from to assign a number/letter to each wire ? How do i look at it ? Thanks. That would be for both styles that need to be connected.

EDIT: Im a moron .... I didnt look at the 95 harness ... I see the numbers :) BUT how do i tell what is what on the 88-94 harness ? remember i took the plug right out of the cluster !!! I had to melt the solder off the plug to get it out.

[chevyz71man]

the 88-91 harness is different then the 92-94 harness. What you need to do is follow tthe ech article on how to go from the moonies to the cluster with a tach. Then go from that to the 95+ harness. Since niether me nor project2005 have this old of a truck we dont have much off the top of our head knowledge on it.

[MStefak]

Doesnt a drac just determine speed ?

[MStefak]

Well I came up with a smart idea today sitting here thinking about the dash swap. 1995. Those are TBI AND new interior. SO they use the same computer as the opne i have thus I should be able to use the whole interior wiring harness from a 95. The special thing I knwo about 95 is it was the only year that the harness was 'non-integrated' meaning theres a bunch of seperate harnesses .. thats where i got my power window harness.

Anyone see anythign im over looking here ? The 1995 harness should plug in and work right with my comptuer correct ?

[chevyz71man]

No the computer changed in like 93 or something. They went to the 4l60 with computer controls. Your truck has the 700r4, with no computer controls. The harness wont just plug and play, you will have to repin the connectors on the harness to fit your computer. It would be a hell of alot easier to use your harness and set up a drac, its not that bad theres a tech article on it.

[MStefak]

See thats what I girued someone would come uyop with .... I wasnt too sure about the ECU .. 95 still isnt OBDII yet though right? The only difference will be for the tranny controls?

Oh and I have standard.

[chevyz71man]

95 is still obdI but it runs at like 8192 buad rate and yours runs at like 160. Also has a couple different tihngs like heated 02 sensor and stuff. It is possible to make work just need a little effort.

[MStefak]

Having stick makes it alot easioer in my mind ... no gay steering column linkage ... no messing with the computer.

The nicest thing about this is going to be being able to get the WHOLE harness ... so my power locks and such will look very very stock haha. So you figure the engine harness will be differnt in the 95 up ? Like where it enters the cab?

[94silv]

thats sweet man. i was jus curious if i could swap the steering wheel or not.. im goin huntin for a jjunker now for the interior.

[emetic]

can you use the new cluster in the old dash or do you have to change them both?

[chevyz71man]

You have to change the dash for the new cluster. The newer cluster is wider and the glass is curved oppisite of the old one.

[Frankenbiker]

Doesnt a drac just determine speed ?

It does, but it's required when you cross the 91-92 line. From 88-91, the VSSB INSIDE the cluster sent speed information to the ECM, Cruise, and ABS computers. The VSS fed speed only to the cluster.

In '92, they moved the VSSB out of the cluster and renamed it a DRAC. The VSS sends it's signal to the DRAC, and the DRAC sends the speed info to the cluster, ECM, Cruise, and ABS.

Note that the various boxes require differing signals, thus the need for some kind of signal conversion. VSS signal is like 16 pulses per driveshaft rev; ABS requires something like 144 pulses, ECM something else.

If you have a truck made in '88-91, the clusters are a direct swap, although the 91 clusters require moving pins around in the dash connector to match the cluster. But no re-wiring is required.

'92 and later clusters CAN be swapped in, but rewiring is required, as well as the addition of the DRAC. There's an article in the FCSU section on how to do this.

-blaine

[MStefak]

Thanks Blaine once again you the man. Just what i was wondering. So i cant get away with not using the dRAC right away ? I NEED it because of teh ECU ?

[MStefak]

Something else I just thought us. Wiring for teh coulmn .. PITA ? or is it faily easy... we need wiring ... ahem Project2005 feel free to chime in ;)