View Full Version : Fixed SI bd., Speedo & cruise in 1 swell foop!!


M.Rad.
07-31-2007, 10:33 PM
Greetings all,

First some background:
I've owned this car for about 9 mo. now. Speedo always bounced, or indicated too high or too low, etc. Cruise control never worked. I had my odometer gears replaced, re-installed my gauges and had no speedo at all. I tested the differential sending unit (see my previous post) but it was ok. I searched this forum and others and found information that the SI board might be responsible.

I took the instrument panel out again, disassembled the cluster, and sure enough there were the two Varta NiCads taking a leak on my SI board. I lloked at the printed circuit traces and , of course found 5 that were destroyed.So now I figure, being this far gone there's not much more damage I could do to it by trying some Wyli-E. Cyote engineering on it.

I started by brushing off as much corrosion as possible with a small stainless steel-bristle brush. I used a thin bladed jewelers screwdriver to pry the connectoras off the batteries. I then then found the thinnest wire I had in my junk wire stash (I knew I'd find a use for it someday!!) and proceeded to bypass the missing traces with jumper wires. It's about the ugliest job of soldering you've ever seen, but they're secure.
I used 24" wires and connected them mechanically to the battery terminals (by folding them over and crimping the wire in the fold). These are still dangling behind the dash not attached to anything.

Well, I put it all back together and went for a drive and found that I now have both a working and accurate speedometer AND a working cruise control!!! The only downside is that I must have done something to my temp gauge, as it bounces erratically for the first few minutes of driving, but then settles down and reads accurately. Whatever, I'm too pumped by the successes to care!!:redspot


Regards,
M.R.

detroit635csi
07-31-2007, 10:44 PM
nice haha...i just replaced my speedo with a used unit...i guess im lazy..hehe...or just too busy redoing my suspension:devillook

but glad to hear of your triumph over the eletrical demons!:buttrock

joshmoat
08-03-2007, 02:59 AM
Nice! What a pain that SI board is. I am still troubleshooting my speedo whoas. I have determined that at least the speedo itself is bad and the board out of the replacement cluster is better than the original. Congrats again on beating this seriously annoying problem.