SCHEMATIC FOR 1979 MERCURY 850 OUTBOARD

jdheaden150 · #1 March 12th, 2002, 04:37 AM

Was wondering if anyone has the schematics for a 1979 Mercury 850 Outboard. Trying to locate the relays for a possible trim/tilt problem. I replaced the solenoid but when I trim up, I only get a click. Voltage is good. Open to any suggestions. Thanks in advance.

jamesk47187 · #2 March 12th, 2002, 06:42 AM

Try BoatUS they have a repair manual for under $30.00 covers everthing.

almost retired again · #3 March 12th, 2002, 12:52 PM

I think that the tilt system that you have has the trin&tilt motor and pump inside the boat, if so you probly only have one relay or solenoid this is used in the up ckt. only (pulls more current to raise than to lower). Check to see if you're actually getting a voltage reading on both sides of the two big terminals when the up button is activated, if not the solenoid is bad.

hopes this helps

Grizzly · #4 March 13th, 2002, 01:24 AM

jd, I think I have the schematics you were asking about. I'll be here 'til 6:30 AM, and back tomorrow after 8:00 AM, Central time. If you want to post an email address, I'll be glad to send them.-G.

petryshyn · #5 March 13th, 2002, 07:11 AM

Hi Griz

can you send me the schematics as well, I,m helping jdheaden150 on this one....

Thanks

schematic2@yahoo.ca

jdheaden150 · #6 March 13th, 2002, 08:00 AM

Thanks Grizz and Schematic for looking up the schematics for my engine. My email address is jdheaden150@netzero.net. Thanks again for your help.

Grizzly · #7 March 14th, 2002, 06:29 AM

jd and schematic I just sent (I Hope) 4 emails to each of you. They are a. single solenoid<<<<b.single solenoid newer>>>>>>c. dual solenoid 6<<<<<<<d. dual solenoid7. If you missed1 or all of them, let me know. I will be back about 6 central time and I will get my daughter, our resident expert to send them. My book covers '72-84>>>> 50 -225 but it only shows 850 model thru'77. If you need something different, give me some info and I'll try to send what you need. Also, I selected the following text if you need any, or all of them, or anything similar, let me know and I'll be glad to send it.

INLINE ENGINES DUAL SOLENOID

a. up circuit inop. (trailer circuit good)

b. down circuit inop. (up and trailer circ. good)

c. trailer circ. inop. (up circ. good)

INLINE ENGINES SINGLE SOLENOID

a. out and up circ inop. (in circ good)

b.out circ. inop. (in and up circ. good)

c.up circ. inop. (out and in circ. good)....etc. -G. a1gr8dad@aol.com

petryshyn · #8 March 14th, 2002, 04:52 PM

jdheaden150

Got the schematics.....

There is three wires going to the actual motor:

>black = ground

>green = down

>blue = up

Take a test-light or meter and check for voltage on the blue wire when trying to trim up. Use the black wire on the motor as your ground connection for the test.

>if voltage is present on blue wire when trimming up = bad motor = open field coil or bad connection or broken wire internally. Don't panic....we'll try to fix it.

>if no voltage present on blue wire when trimming up = bad solenoid or no power supplied to the solenoid.

let us know!

petryshyn · #9 March 15th, 2002, 04:48 AM

Hi Griz

got the schematics! thanks muchly.....you are a gentleman!

Grizzly · #10 March 15th, 2002, 07:57 AM

Thanks Schematic, you've probably helped every member of this B/B in one way or another. I'm a rank amatuer, but I've got a book on old Mercs and a growing list of websites. If I can ever help just holler.-G. BTW, I don't know how to break it to you, but NOBODY takes what you say with a grain of salt.