project: digital cluster
Purpose:
To
replace the stock instrument cluster with a digital LCD cluster.
Supplies:
-wire stripper
-digital instrument cluster and wiring
-spare prelude wiring harness
-electrical diagrams for both vehicles
-plenty of patience
Instead of doing a writeup at the very end, I'm going to post my progress as I work on this project. This project will take considerable time to complete and there is a good chance it will not work completely properly. The updates will be listed chronologically from start date so the latest updates will be found at the bottom of the page.
3/1/04 - Went to the junkyard today and pulled the digital instrument cluster out of an 88-92 Mazda 626 LX. Also grabbed all wiring I could see connected to the cluster (critical!). I also picked up a wiring harness from another Prelude to assist with the conversion. I didn't want to chop apart my car's wiring in case this wasn't going to work. Currently in the process of labelling the important wires and matching them to the Prelude harness. For reference I've used the Haynes manuals for both vehicles, plus the Prelude shop manual.
3/6/04 - My friend at BCIT has finished mapping out the Mazda cluster wiring for me (diagram 1, diagram 2). I'll also have him do final checks on the Honda harness to match up with the Mazda. It appears that the fuel guage sender will be compatible with the Mazda cluster; it was something I worried wouldn't work. I will also have to somehow find a way to move the speedometer cable over to the right side of the cluster. Anyways, I removed the Prelude's cluster and compared the fit... This will take some magic but I believe it can be done. In the pics below I've got my disassembled dash and the two clusters side by side. If you're anything like me, you'll attempt to pull the Prelude cluster out wondering why you can't reach the damned speedo cable. After much frustration, you will check the shop manual where it reveals the secret of removing the lower dash components to reach in under. Haha enjoy.
3/7/04 - Finished up doing a diagram for the Prelude cluster. Some stuff I wasn't able to accurately label but since the Mazda cluster doesn't hook up with any of them it isn't really an issue. My diagram (click here to view) shows the 4 groups of wires entering the back of the cluster. I will use both diagrams to line up the wiring from the Prelude harness and the Mazda cluster. The process of swapping will take several hours and I may end up having to drive to work without a working cluster! Look for more updates within the next couple of days when I begin the wiring swap.
3/13/04 - Today was swap day. Since I wasn't able to print off copies of my wiring diagrams, I decided to cut small lenghts of the Prelude harness wires and then attach them to the corresponding Mazda cluster wires, allowing me to simply match the Prelude harness wires with the same wires in the car. I did a quick hack job with the wires just to see if it would work... and what do you know? It works perfectly! Fuel/temp/speedo guages all accurate! One thing I had to do though was move the speedo cable from the left side of the cluster to the right side. The pics below show the processs.
The tip of the speedo cable must be removed in order to pull it back into the engine bay. I then ran it into the hole where my amp's power line runs. Once put through, just guide it up through the dash until you see it out the top. The tip goes back on by screwing it in and moving it around. You may want to crimp it in a bit too.
Once the cluster was wired up, I took it for a test drive. I'm going to have to get used to the Check Engine warning now displayed as Windshield Fluid Low light since the cluster didn't have Check Engine... I took the pic below while driving after my speedo cable broke.
05/05/04 - Whoa been a while since the last work was done... Anyway, the cluster swap is finally fully complete with the panels back on and speedo cable working again. See the final pics of the swap below. Putting the final pieces on was quite a bit easier than I originally expected. I had only minimal dremel work to get the proper fit.
You can contact the author at [email protected]