89 Civic hatchback DX

Bought an 89 crx si cluster cause mine had no tach And my gas guage wasnt working. Put it in and everything kinda works fine but the cluster lights are very low like my battery is low. When i turn on my signals rpm goes up and down like crazy.

So that cluster was junk! Bought another 89 si cluster but same problem lights were low can barely see. Im like EF it!

Put back my DX cluster everything works. even tried changing the bulbs on the si cluster still no luck.

Anyone came across this problem?

 

From what it looks like check your speedo cable? Or did your tach work with the other ones? If it did, buy a working cluster?

 

Anyone know whats this for? the part where i circled red.

Still having problems. I bought another si cluster but some parts are not functional. Could that part i circled in red be the problem?
I see si cluster without that part.

 

thatts like the main thig to it..it controls everything..if ur car doesnt have the wire that connects to it it aint gonna work..i had the same issue with my 89 sedan..i bought a 91 ef sedan cluster and had that part and after i found out it doesnt work because the cluster changes...im preaty sure thats whats wrong with yours.. that best cluster that will fit yours is the 88 ef wagon cluster.. plug and play..

 

Check your grounds especially the battery terminal ground trans to chassis to battery

My car had the same exact problem ground was loose solved issues

 

Oh so i see, where do i get that plug? does it only come in specific cars?

and which car come without that part?
only 88 wagon?