Problem: The gears on the transmission end of the speedo cable on my 91 Civic DX Hatchback (auto) are missing some teeth. I heard the transmission case will have to be pulled to replace them. Not having a speedo doesn't bother me, but not having overdrive does. Since the speedo cable drives the sensor that activates the overdrive, no speedo cable = no overdrive.

Question: Is there any way to 'hot wire" the leads from the speed sensor to the trans and install an on/off switch so the overdrive can be manually controlled? If so, that would save a lot of money. Has anyone ever done this? Is there any reason why it wouldn't work or shouldn't be tried?

 

bump

 

if the sensor is electric...and has wires going to it...then yes you probably can cut the wires and hotwire it...i hotwire lots of things cuz my car is ghetto...like my radiator fan and my heater motor are both hotwired with a switch lol...good luck

 

I can relate to that! The main thing is that it's still a solid car and looks decent and runs well, so I plan to keep it going as long as possible. Maybe that is a curse of Hondas...they keep running so well long after other makes would have crapped out!

How does the instrument cluster come out? I haven't been able to find any screws to take out. The speed sensor is supposed to be on the back of the speedometer. I don't know how many leads are connected to the sensor.

The check engine light comes on because of the sensor. It usually comes on after I have been going fast enough for the overdrive to be triggered and then I coast, which would normally kick it back out. The check engine light always resets when I start the car again, but it comes on again as noted. Not a big deal, but it would be nice to fool it into thinking everything is working normally.

 

i dont think a switch is going to work once you take it apart youll see that the vss is attached to the spedo who knows i could be wrong. to take the cluster cover off theres 2 little covers that need to be poped off on top of the cluster cover towards the windsheild you can see them standing outside the car. and 2 more screws at the bottom edge of the cover uder where the switches are. then youll see 4 screw holding the cluster in there. if i were you i would just replace the whole tranny look on classifieds or junk yards cause usually no one wants an auto tranny. i threw a perfectly good one away not too long ago.

 

I would rather have found a Civic like this with a 5 speed, but the only ones I could find had far more miles on them and had been hot rodded by kids. This one was in nice shape from the original owner and the car spent most of its life in Florida instead of the nasty rust belt. Still, the next one I get will need to have a 5 speed so I don't have to mess with the problems of an automatic.

 

I came up with a real tacky idea last night to solve this problem. This may be the most goofy thing in auto repair, but I figured it's worth a try.

Everything comes down to the speedo cable not turning because some of the gears in the transmission are stripped. How about if I just work around that by rigging a 12 volt motor with a fitting for the end of the speedo cable that should plug into the transmission. If I can find a motor to turn the cable at the same speed as an indicated 35+ MPH, that would allow the speed sensor to enable to the overdrive, and it would also keep the check engine light from coming on since it would appear that things are working normally. With an on/off switch to turn on the motor when I want overdrive, I could manually control it. I know this sounds hokey, but I don't see why it wouldn't work. Any ideas?

 

that sounds like more work then just replacing the tranny.