Speedometer not working

[maxumus]

Any tips on where to look first and how to hook up speedometer again. I have a 96 maxum with a 350 mercruiser alpha 1 drive. I believe the outdrive is a 2000, it was replaced when the previous owner hit a lateral dam on the Mississippi. When it was replaced the speedo won't work. I have heard this happens at times. I always had late 70's equipment before and had the speedo pickups but the newer drives have the speedo tube in the outdrive. Any tips on where to look and if I have to take the outdrive off again or not would be helpful.

 

[cheburashka]

Re: Speedometer not working

Couldn't hurt to try disconnecting the tubing from the back of the speedometer and blowing compressed air through it. Could be that grease or sealant got caught in the orifice in the outdrive that carries the air pressure to the gauge.

 

[Don S]

Re: Speedometer not working

Right in front of the shift shaft on the drive is a quick disconnect fitting for the speedometer. They probably forgot to hook it up when the drive was replaced. You can just tilt the drive up to access it. Go to page 2A-11 and 2A-12 in the link below.
http://www.boatfix.com/merc/Servmanl/14/14a2.pdf

There is also a small hole in the leading edge of the lower unit that may be plugged up. Check it too.