Lowrance shuts off with blower

[fxdl]

Hello,

I have a 1999 Lund Tyee with a 4.3L Mercruiser. I just installed a Lowrance Sonar/GPS. I wired it to a 10 amp accessory fuse, so I could cut power to the Lowrance when the master power switch is turned off. My stereo is also wired to the same accessory fuse.
My problem is when I turn the blower on, the Lowrance shuts down. I've noticed my trim gauge also drops when I turn on any accessory, lights, bilge, blower, stereo, etc, if the ignition switch is off. If the blower is already on and I turn on my Lowrance, it stays on OK. I'm guessing there must be a surge of power to the blower when starting it, causing the Lowrance to drop below what's required for it to stay on. I wouldn't think those little blower fans would required much power to run them.
Any ideas where I might start troubleshooting?

Thanks

 

[dingbat]

Re: Lowrance shuts off with blower

It could be anyone of a couple of things.

1. It could be your battery is getting weak
2. One of the battery cables has a problem
3. You have too much wired into a single circuit

Swap out the battery or use a set of jumper cables to hook up a known good battery to your system. If the symptoms persist at least you've ruled out the battery.

 

[fxdl]

Re: Lowrance shuts off with blower

Thanks Dingbat, I'll look at that, but it won't be for a couple of days. I'll let you know how I make out. Just wandering if I can do this test with a deep cycle battery? That's all I have available to me at the moment.

 

[dingbat]

Re: Lowrance shuts off with blower

A deep cycle will work. That's all I use.

 

[Splat]

Re: Lowrance shuts off with blower

This may be a line loss issue due to too much being pulled through too little gauge wire over a long run.

Other possibilities are a weak battery. Or even a worn or aging blower motor that is drawing lots of current on startt up.

Could be as easy as a bad connection at the battery.

I would be interestred in what gauge wire is feeding this circuit, and how many amps are being drawn through it.

Do you have access to a amp meter? Or can you grab ahold of the wire after a few minutes and see if its warm? Heat can indicate too much current.

I would start by cleaning the battery terminals tho. Its easy, quick and free. If that don't help check back and we can give you some more help.

Bill

 

[Silvertip]

Re: Lowrance shuts off with blower

Any motor has a high in-rush or start-up current draw. You experience shut down when the blower is turned on. That is caused by the in-rush. A good battery should not allow that to happen but the wire gauge feeding everything you have connected to that circuit, what you have turned on at the time, and the condition of the connections can have an impact on this issue.

 

[fxdl]

Re: Lowrance shuts off with blower

Problem doesn't seem to be the battery. Battery tests at 12.31 volts and most accessories test at about 12 volts. The bilge blower has a voltage drop to about 9.5 volts.

I ordered a new blower. Mine was getting pretty loud anyway. We'll see what happens with the new blower.

 

[Silvertip]

Re: Lowrance shuts off with blower

The accessories you tested are low current draw devices and will not pull down the battery. The blower is a high current draw device and will pull down the battery. Replace the battery with the one from your car or truck and see what happens. Even the starter should not pull down the battery that far. If the blower was drawing that much current it would likely blow the fuse or circuit breaker. I feel you have a battery going bad.

 

[fxdl]

Re: Lowrance shuts off with blower

Well I got the new blower, but it didn't change anything. I connected another battery and that didn't help. I'm not sure what gauge the wire is, but I'm sure it's original wiring. It appears to be the same gauge wire that's attached to the new blower. Any other ideas would be greatly appreciated. I tried calling Lowrance, but that's a joke. Got tired of being on hold.

 

[Silvertip]

Re: Lowrance shuts off with blower

If you are measuring as low as 9 volts in any circuit on the boat you have a power issue. Either the battery cables are bad, terminal ends on the cables are corroded (either or both ends), the cable connections are bad (both ends), or the feed to the affecgted circuits are bad. Low voltage is the cause of the locator dropping out. Work from the locator plug backward to find the point where low voltage turns to normal +12 volts with the blower on..

 

[fxdl]

Re: Lowrance shuts off with blower

I've cleaned the battery cables on the battery end. I'll check to other ends of the cables. What's the locator plug? I'm not familiar with that term.