Nissan Repair: 1995 nissan maxima cruise control and tach problem, vehicle speed sensor, nissan maxima

Question
the cruise control on my 1995 nissan maxima does not work. you can turn the system on, and get a green light, but cruise does not engage when pushing the set button.  the tachometer on the car does not function properly also.  the tach almost always reads low and if the rpm reaches 3200 rpm the needle just drops to 1200-1500 rpm suddenly.  i believe these two items are connected, any help would be greatly appreciated.

Answer
Stephen,

The two systems are unrelated.  I would look at the brake or clutch switch if a manual.  Also, if the vehicle speed sensor is not working properly that could cause the problem too.  You should check the cruise control mechanism under the hood too.  I would purchase a Haynes Manual and follow the wiring diagram and look for where the system is not getting power.  Unually, it ends up being one of the disengage switches like those I mentioned earlier.  That is, the system will power up but not engage with a defective switch.  These are for safety so replace if they are defective.  The tach is probably going to end up being the feed wire or the tach itself.