Background:

I'm using a 90-91 Si cluster in an 88 with 88 underdash wiring. All other lights (check engine, brake, ect.) work, but no cluster lights. I've tried two different dimmers. Just to be sure, I checked with a multimeter, and I've got power to the red/black wire, and when I plug in the switch, I've got power to the red wire, using the actual ground in the other plug as a ground source, so I know that the ground is good too. Fuses are good.

The only thing I can think of is on the 90-91 wiring harness, from which I clipped the 90-91 plugs, there was a relay type box, that said ak-22 or something like that. I am almost certain that my 88 did not have one, and I can't think of why it would interfere, or even how to hook it up if I was going to use it. Really, even if its a relay, the lights should work without it.

Also, there's a 5-prong plug opening in the back of the 90-91 cluster that's blue. What goes there? Is that messing with my lights? There's no way that all the cluster lights went out al at once, that's crazy.

Somebody help!

 

The blue wire you talking about is for 90-91 civic....i bought a 88-89 cluster not too long ago and only two of my wire had spot to plug into and no place to plug in the blue one...i didnt really know anything about cluster just what i read its a plug and play...but i got my money back and bought one for my year(90-91)and it had 3 spot for my 3 wires...and i think i pop someting when i pluged in the 88-89 cluster because im seatbelt ligh keep on blinking after 5mph in both my old cluster(with no tech) and my new si one...all and all 88-89 cluster plug and play.. 90-91 plug and play...also when i hooked up the 88-89 cluster only my brake light and i think door light came on but nothin eles work not even my rpm

 

And i dont know what the blue wire is for......i guess my word is useless in this my bad

 

this happened on mine too. theres a relay kind of above the gas pedal. replace that.

 

right, what I'm saying is that there's no relay on my 88 wiring harness, and that I don't know how or where to install the relay that was on the 90-91 harness. Does anybody have pics and diagrams of the wiring for the relay? or even pics of the relay? That would be great.

 

also, the blue plug I'm talking about is a plug on the 90-91 harness that is not present on the 88-89 harness. there's a blue place to plug in a 5-prong harness on the back of the 90-91 Si cluster, and There's no plug on the 88-89 harness for me to use.

 

im kiknda opposite of you.. I have a 90 si.. but I put a whole 89 CRX dash in there.. cluster an all.. So right now the only things that dont work are my blinkers and hazards..... But im in the process of connecting the relay and everything else missing from the 89 harness....But at least everything else in my cluster works...

Look for wiring for both the 90 si and 88.... see the differece and switch the pins around..

 

nono, the pins are fine, they've been switched. I know I'm on track there. Thanks though.

 

where did you put the relay? That's probably my problem

 

dimmer was NOT good. Apparently two separate dimmers can go bad at the same freaking time. On a whim, I bypassed the dimmer, they lit the hell up, lol. thanks for the help.