Sonar shuts off when drive engaged

[Sliver]

Greetings all,

I have a new old boat (89 Sunbird) with a 3.0 OMC drive. I installed my Lowrance Elite 5 by tapping a hot wire under the dash and tested in the driveway, all is good. Get it out on the water, turn the unit on, start the motor, idle, all is good. Shift into forward, off goes the sonar. I can have the unit on and use the control in neutral up throttle the sonar stays on, but the instant I shift into gear it shuts off. Moved the wire from the transducer away from the control wires, no change. I believe I need a separate line from the battery? Any other ideas? Thanks a lot.

P.S. I would guess that I should fuse the line right at the battery right?

 

[dingbat]

Re: Sonar shuts off when drive engaged

Unlike the past, modern electronics are very tolerant of power abnormalities. If it runs until you put it into gear, I doubt if you have a power problem.

The first thing I would do is pull the power cable off the unit and make sure you have 12 VDC at the connector with the boat in gear. If you have power as I suspect, start looking at the location of the transducer. Transducers will not toloerate a lot of turbulence

 

[Sliver]

Re: Sonar shuts off when drive engaged

Thanks Dingbat,

I should have noted though when I was sitting in the middle of the lake trying to figure this out the problem occured even with the motor off so turbulence would not have been an issue. I was not able to check the voltage in gear but will do so. Any other thoughts? Thanks

 

[NYBo]

Re: Sonar shuts off when drive engaged

It sounds like you tapped into the shift interrupter circuit. You should tap into the fuse block, using an unused fuse.

 

[Sliver]

Re: Sonar shuts off when drive engaged

NYBo,

Is the shift interrupter sort of like a neutral saftey switch?

 

[dingbat]

Re: Sonar shuts off when drive engaged

It sounds like you tapped into the shift interrupter circuit. You should tap into the fuse block, using an unused fuse.

I had the same idea but the interrupter / neutral switch works off ground. Could be using that circuit as a ground

 

[Sliver]

Re: Sonar shuts off when drive engaged

I can't remember exactly but I thought I went to the BAT side of the ignition switch. I will check further. But have to work now :<(

 

[Sliver]

Re: Sonar shuts off when drive engaged

More thought though.... My guess is the interrupter circuit cuts the ignition power when in gear so... if thats where I tapped that's the problem. Boy I hope so! Many thanks to all.

 

[dingbat]

Re: Sonar shuts off when drive engaged

More thought though.... My guess is the interrupter circuit cuts the ignition power when in gear so... if thats where I tapped that's the problem. Boy I hope so! Many thanks to all.

I checked the schematic. The interrupt circuit (red/yellow wires) cut the power monetarily as you shift gears. Once in gear, you should be able to power up the unit again. The purple wire is hot continuously

 

[bruceb58]

Re: Sonar shuts off when drive engaged

The shift interrupt is all back at the engine. The output of the ESA momentarily grounds the coil. There is no way that circuit is connected here.

Typically, Sonars are connected to a constantly hot power source. You want to be able to have it on with the engine off.

if you don't have a battery switch, you could hook it straight to the battery. If you do, it needs to be connected after the switch, typically at the fuse block if you have a spare location.

 

[Sliver]

Re: Sonar shuts off when drive engaged

No battery switch, no fuse block, I just found a wire that was hot with the key off and tapped it. I will check tonight if I can. The unit has an inline fuse holder but if I go back to the battery I would think I should put a fuse there too?

 

[bruceb58]

Re: Sonar shuts off when drive engaged

The unit has an inline fuse holder but if I go back to the battery I would think I should put a fuse there too?

Yes.

 

[dingbat]

Re: Sonar shuts off when drive engaged

The shift interrupt is all back at the engine. The output of the ESA momentarily grounds the coil. There is no way that circuit is connected here.

My Bad, the red/yellow is the neutral switch.

 

[bruceb58]

Re: Sonar shuts off when drive engaged

No battery switch, no fuse block,

So how do navigation lights, horn, blower... get their power? There has to be a fuse panel underneath or behind your dash.

 

[Sliver]

Re: Sonar shuts off when drive engaged

The dash has a fuse on the top next to each device switch, blower, bilge, lights horn etc.

 

[NYBo]

Re: Sonar shuts off when drive engaged

Yeah, I was clearly off-base about the shift interrupter circuit.:redface:

I can't figure out what circuit would be hot only with the motor off. But, no matter. Tap off the line side of the last fuse on the panel.

 

[bruceb58]

Re: Sonar shuts off when drive engaged

The dash has a fuse on the top next to each device switch, blower, bilge, lights horn etc.

Ok....That means there is a power bus back there. Hook an inline fuse there. You don't have to go all the way back to the battery.

 

[Sliver]

Re: Sonar shuts off when drive engaged

Argghhh, So I found another hot lead, and after connecting my test light and shifting out of neutral and seeing the light still on I tapped it. Same problem. Strung a wire from the battery to the unit... same result. I would have never guessed that it was the ground side that was the problem!!! Switched the negative wire to a different ground and all is good. Thanks again for all the help. No wonder Iboats has so many happy users, what a great bunch of folks!

 

[bruceb58]

Re: Sonar shuts off when drive engaged

LOL...so where was this ground you were using??

 

[Sliver]

Re: Sonar shuts off when drive engaged

bruceb58,

I be 55... I did not have time last night to switch things, just temporary, I will get back on this tonight, have to go to work now. I will let you know which wire was the culprit.