Autometer temp gauge with mercury sender?

[dschifan]

I added autometer temp gauges to my boat and hooked them up to the stock mercury sender and they seem to be about 30 degrees off or so. Is it ok to run them hooked up to the mercury sender and just account for the old differences in temp? or should i buy the autometer sending units and get them mounted and hooked up? Also i was unsure about these gauges senders being cylinder head temps and how i would hook them up since i cannot seem to find a threaded hole on my 1998 300 promaxs. do i have to make a custom bracket to have them sit against the heads to get the reading? this is what sending units are suppose to go with the gauges http://www.danamarineproducts.com/Pr...9-f037a6933917

thanks!

[vnemous]

The sweep of the guage has to match the sender or it wont be close.

[HP]

You will have to drill and tap a 1/8 pipe thread into the top of the starboard head and insert a water sending unit. You are reading head temperature if you are connecting to the OEM sender in the head.
The Autometer guage has to have it's own sending unit

[dschifan]

thanks guys for the replys. where is the exact location on the starboard head that is best to drill it? So i want to drill all the way through the head to make contact with water, or do i just let it read the head temperature and drill partially to have it mounted to touch the head?

[HP]

Remove the thermostat and you will be able to locate the right spot for the sender. You will be drilling into the water jacket.....but as you will see with the thermostat out the sender you will need is kinda short maybe 1.5 in. long. I wish I had the correct part number for you but any auto parts shop has them. Just remember get the correct OHM sender for the guage... Most are standard 240-33 ohm but some are different.
Yes the one @ Dana Marine is the one I was talking about.........