1995 340 battery switch questions
 

Hi,

I was told when I bought my 95 340 new to always have both battery swicths in the all position.

I have read different opinions on other sites (but not specific to PQ wiring)

Can anyone explain to me how these switches are wired (which switch powers what) and the signifiance of the switch settings.

Thanks!

Jeff

I have been told if you have an E.F.I. / M.P.I. engines to have each one engine on its own designated battery. So you would have your port engine battery selector on 1 and your starboard selector on 2, or vise versa.

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05-18-2005, 09:25 AM #6
Macklin
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Join Date: Dec 2001
Location: Virginia Beach
Posts: 1,491
'08 37 Active Thunder Re: PQ 95 340 - Battery Switch Question

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We received this memo from PQ shortly after receiving our boats and asking the same questions as you guys. I have sent this letter to several people already. Rather than go that route again, I have decided to just post it here:

January 28, 2002

To: Bill Rippel, Dave Goodman and Macklin Smith
From: Mark Winia
Re: 340/380 Battery Switch Wiring

Gentleman,
Attached is a wiring diagram from Perko, the manufacturer of our battery switches showing the basic wiring scheme of our battery switches. I have also included a copy of the memo from Mercury containing their recommendations for the battery switches on twin e.f.i. engine installations. As this memo states the engines should always be run off of separate batteries. Whether you choose to run your starboard engine off your port battery or your starboard battery is up to you, as long as the other engine is run off of the opposite battery. In other words, the port battery switch should not be left in the same position as the starboard battery switch and neither switch should be left in the “all” position while the engine is running.

As for the other wires routed to the battery switches, here are some answers:

Starboard switch, #1 terminal: Attached here should be a 2 gauge red jumper to the #1 terminal on the port switch. If space permits, the amp feed and the bilge pump feed are connected here so they will have constant power.

Starboard switch, #2 terminal: Attached here should be a 2 gauge jumper to the #2 terminal on the port switch. The starboard battery cable also connects here.
Starboard switch, common (center) terminal: The starboard starter cable attaches here.

Port Switch, #1 terminal: Attached here will be a 2 gauge red jumper to the #1 terminal on the starboard battery switch. The port battery cable also connects here. In addition, we will typically connect a feed from the battery charger to this terminal and one of the mercathode feeds.

Port Switch, #2 terminal: Attached here will be a 2 gauge jumper from the #2 terminal on the starboard switch. Also, we will attach one of the battery charger feeds here and the remaining mercathode wire.
Port Switch, common terminal: The port starter cable attaches here.

Misc.: The feeds to the breaker panel for the helm and cabin mains and drive and tab mains are connected to the common terminals of either switch depending on the space available. By turning one battery switch off and leaving the other on should allow

Hey, that letter looks familiar! :D

Keep in mind this is for the '02 models we purchased.

If you are talking about the 1995 34 Vyper with a carb setup than run them both in all as it charges better wile running with both in all, and then switch to 1 & 2 while parked to reserve the starter battery while running your stereo and such, you will notice a better or a more even charge rate on your battery switches while running in all, but this is with a 500 HP carb setup, not sure about MPI set-up. I also run two deep cycles on one bank and a single deep on the other for starting back up.

I was kind of wondering about this as well. I have a 95 PQ Laser with a 454 Mag EFI. This summer for some reason I blew out (2) Electronic Control Modules in my distributor. I have always run my boat with the battary switch set on all. My mechanic and Mercrusier are saying there was a bulletin put out in 95 to only run this motor on 1 battery. For some reason I am getting a voltage spike which is blowing the ECM. After the last repair I ran once on one battery and it ran fine. I am wondering why this became an issue this year when for the past 8 years I always ran on 2 batteries. Anyone have any ideas. Thanks!

Any of the electrical engineers have any input ? Good question.

We ran our 98 laser 454 mag with switch on all for 9 seasons with no issues.

I can't imagine a volt. spike from 1,2 or3or4 or however many battery's. Alternator regulater yes.12volt battery's are 12 volt,s or 12.4 depending on state of charge.Your sys. should handle 14.5 volts anyway,alternator's should put out between 13.5 and 14.5 volts. Batterys don't spike voltage by