speedaddict78

i have a 78 cutlass with the single sweep speedo and dummy lights.
i have a cluster from an 87 with the rally gauge pack. pretty sure my original cluster only had one plug in the back. the 87 has 2.
i have the 87 bc its a parts car so the complete harness is available to me.
do i need to pull both harnesses out and swap/splice them?
or can i cut the two connectors for the 87 cluster with like a foot of wire, and splice it into my 78 harness?

anyone ever do this before?
any tips advise would be really appreciated..
also if someone can point me in the right direction to service manuals with detailed schematics for both years, that would be great too.. because i also want to swap over the power windows, rear defroster and pulse wipers to my 78..

thanks

Lady72nRob71

If you know the 87 set will physically fit in your 78, then get the plugs with wire for the 87 set. It is possible you might be able to just swap the connectors' internal pins but not sure if they are different.

The 78 uses one plug. 1980 to 88 used 2 plugs, as more options were added as well as the engine computer.

You can get away with only using the main plug, as the second one was only for the check engine light and temp light on the rally packs.

While the Haynes manuals can kinda get you by, I recommend the factory service manuals if you plan on doing this much work on and keeping this car. Much more detailed and informative.

Oh - make sure the speedo cable attaches the same way, too.

Any other good parts on that '87?

speedaddict78

Thanks a lot. I'm pretty sure they are the same size. ? I'll have to double check that..

What are you looking for? Let me know and I will take a look tomorrow night..

I have a bunch of nice dash pieces.. the wood grain panels with the vents.. I have like 3 clusters with the rally gauges.. I have the blue bucket seats and console.. I'm still debating on whether or not I'm going to use them..

Lady72nRob71

Not sure what you have but seeking factory radio and rear speakers is destined for scrap. I do need the optional extended range speakers if it has them.