OMC 3 wire tnt pump to 2 wire control system

redlinj

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Had to put an evinrude ob with a 3 wire tnt pump on a boat with the later 2 wire setup. I read many posts but still no luck. Everything works as it should when direct connected to a battery. I tried Faztbullet's advise from another thread, see below,. The existing relay box is actually 4'x5 3/4" not the 3x4" everyone else seems to mention about. Anyway, I removed the middle black wire from ground on each relay and connected the blue to blue, green to green and the 3rd wire(black) directly to negative on the battery. Nothing happens other that a mild click from both up and down. Perhaps I should have just removed the ground from the down(green)relay and see what happens or just order the $30 3 wire pump to 2 wire control set up. Any suggestions? A diagram would be great. September 30th, 2012, 08:30 AM
Faztbullet
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#5


Re: Can I use a 3 wire tilt and trim motor with the "relay" box.

To use the existing relay box just remove the black wire to center of the relays usually marked 87A, hook your motor to the blue and green wires from relays and install black wire from 3 wire motor under a good ground, This gives you a separate relay for up and down.
 
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ok under the relay are post numbers they should be

30, 85, 86, 87, 87a

the ground wires you removed should have been on the 87a posts. Once removed you should hook the blue wire of the trim motor to terminal 30 on the relay that has the small blue wire on the 86 post.
Hook the green trim motor wire to post 30 on the other relay that has the small green wire on post 86

both of the relays have a power wire on post 87 which should be fused (you may have blown this accidently)
both relays should be hooked to dc neg on post 85

on the trim motor hook black to dc negative

I think you may have hooked the trim motor to the posts where you removed the ground wires.

Please ensure there is a fuse inline on the positive cable going to the post 87 on the relays (if it was stock then it would have had one already)
 
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redlinj

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The relays are encased in plastic/rubber and no visible markings. The fuse is good. I removed it and tested it. No, blue and green trim wires were connected to blue and green wires coming from their respective relays. As you can see in the pics, the black wires from each relay have been removed from the bar.
 
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sry redlinj but the web site pictures do not work correctly. can you post to photobucket or something like that. With pictures this should be a easy fix.
Can you hear the relays click when you toggle the switch up or down ?
when you removed the black wire did it go to one place on the relays or did it go to 2 different places on the same relay?
 

redlinj

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Yes, I can hear a click coming from the relays, albeit rather faint. Each relay has the black wire coming from it and they were both attached together on the bar. In the bottom pic you can see the 2 individual black wires and the empty space on the bar where they were attached. Can't really get a good view of the relays without removing it off the bar, but there are 5 wires on each relay, so appears they are 5 prong---just can't get a decent view of them. I will try and get better pic if that will help.
 

redlinj

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The relays are Bosch. There are 2 sets of #s on them. 9 334 485 007 and 0332204101. Again, no visible id for the terminals like 30,85,86,87 and 87a. Could be obstructed by the external housing which may help to waterproof it. Looking straight down at it, Green or Blue, depending on which relay your looking at, is attached to the top terminal. Middle row has 3 terminals. The left and middle are jumpered together and grounded to the bar. Right terminal is smaller green/white stripe(tracer) wire which I would say goes to the switch. Bottom terminal is Red wire.
 

redlinj

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Can't seem to get pics to post properly. Any suggestions? I removed the jumper connecting the center and left terminals on both relays. Now only the left terminal on each relay is grounded to the bar. Still no success.
 
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2,906
pictures have to be uploaded to a outside site then linked to the forum. I did pm you a email address but im not sure that works either.
Its time to get a volt meter and work out whats going on as this should be a walk in the park. If the relays are clicking power should be going to the pump.
 
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2,906
ok its confusing that you have sent pictures where some wire are removed then put back on. Turn the relay upside down like in the first picture and unplug the relay from the base. looking down the back of the base where the wire enters there is a spade connector with a security tab (middle post that's jumped to the next post over). Get something like a little screw driver and from the relay side go down the side of the spade so the security tab is pressed in then pull the spade out of the block. the spade should come out the same side the wire goes in. (they can be a pain to get out as they are designed to lock when pressed in)
Once the middle spade has been removed tape over the end so it can be used at a latter date then put the black cables back on the terminal strip (now only the wire to the side of the relay will be grounded). put the relays back in one at a time and test. Relays should make a nice sold click sound when activated.
 

redlinj

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Have the wiring set up with the ground on 87a removed on both relays and now just grounded from the spade to the left of 87a. Have 12 volts to the relays and 12 volts after the relays when engaging the tnt switch. Problem is when the 3 motor wires are connected, I loose power after the relays. Gotta be that the 3 wires coming from the motor are causing a short or something. When I take these same three wires and direct connect to the battery every thing works as it should! When I have only blue or green connected, there is power to the other but not the wires connected. This has got to be just a misplaced wire or short, but is extremely frustrating.
 
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oh ok that means you have a bad connection on the power wire as you are suffering voltage drop. if you unplug the blue wire where you connected the trim motor and get some one to press the toggle switch you will probably see 12v on the meter. Now if you plug in a small light (test light or any light) and now measure the voltage you will probably see the voltage drop. On trim systems this can happen because after they are originally assembled they use a thick black water proof paint over the copper joining strips at the terminal strip. You need to clean the connections on for the red wire.
 

redlinj

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That makes sense! Will run that test and clean up the connections in the morning. Thanks
 

redlinj

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BINGO! cleaned up the connections and guess what! Motor goes up and down like it should. Thanks Glenn!
 
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