Jump to content
Sign in to follow this  
Mhans

reversed battery Connections-Merc bravo III

Recommended Posts

.distracted and preoccupied..last evening, I placed both batteries in my 2011 Sunesta 264 and attached the cables trying to beat the setting sun....All was well until I turned the battery switch on and a brief spark across the VSR module was seen. And no power.... After I briefly panicked, I looked into the battery compartment and my horrified worries were confirmed. I had dropped the batteries in "backwards" to the way I had taken them out and attached the yellow ground cables to the (+) electrodes and the red positive cables to the (-) posts on the batteries. Removing the cables and reattaching them correctly now only gives power to most of my accessories/lights/horn/blower,etc. BUT I have NO power to the dash guages/trim/tabs and NOTHING happens when I try to crank the engine. I have looked at all the fuses (that I can find) and they are fine. Circuit breaker not tripped. No breakers tripped on panel behind dash.

So... Alternator??...starter???..blown diodes somewhere else? ..VSR module?

Thanks

Share this post


Link to post
Share on other sites

Main breaker wasn't tripped...I'm assuming you mean the "Main breaker button" near the electrical connections on the left side top if the engine.

Mike

Share this post


Link to post
Share on other sites

Main breaker wasn't tripped...I'm assuming you mean the "Main breaker button" near the electrical connections on the left side top if the engine.

Mike

Press it anyways and see what happens.

Share this post


Link to post
Share on other sites

Oh man...I replied to your earlier post before I saw this one.

I hope that you simply find the main 90 amp fuse (item #8) on starter motor is blown. The symptoms you describe are classic for a blown 90 amp fuse on a MerCruiser engine. Mercury part # 89-79023T90 which thankfully you can change yourself, and should be stocked at every dealer.

NOTE: disconnect all the battery cables first, then when installing the 90 amp fuse in the picture below, care will need to be taken when tightening the nut (item #4) The solenoid (item #2) on the starter is rather fragile. Snug but don't over tighten.

9798.png

After you have replaced the 90 amp fuse, try the following:

If the 2nd battery is factory, it will have a VSR - voltage sensitive relay. With this particular set up, it's important that you get the starting battery to be in the # 1 position.

The reason for this is that when the battery switch is in # 1 position, the VSR will allow both # 1 and # 2 batteries to be charged off the alternator as required, but will only allow the # 2 battery to charge off the alternator when the battery switch is in the # 2 position. (if memory serves)

Step 1. The easiest way for a layman to find out which positive (+) battery cable is for # 1 or # 2 is to connect all the negative cables to each battery. (all yellows, with 1 black cable for the power trim) i.e. each battery will have one large yellow - cable attached. If your boat has a short individual yellow - negative cable, use it to attach the negative posts on each battery together like in the picture below.

Step 2. Connect 1 of the large red + cables to a battery. (1 large red +, and 1 smaller red + cable for the power trim won't be connected)

Step 3. Turn the battery switch to # 2.

Step 4. Turn on the stereo (or try to) or any other accessory, turn the key switch to the 'on' position, etc.

Step 5. If you have power, then you know the 1 large red + cable attached to particular battery is for # 2. If you have no power on # 2, but you do on # 1 position, than the battery with the large red + cable attached should have your starting battery placed there.

NOTE: the small red + cable for the power trim should be attached to your # 1 battery. That way, should you have listened to the radio all day at the beach on the # 2 battery and it's now flat, you'll be able to start the engine off the # 1 battery and be able to trim the drive.

Step 6. Mark each large red + battery cable # 1 and # 2 as required for future reference.

Step 7. If required, turn the battery switch to the 'off' position, remove the battery cables, position each battery as required, and connect the battery cables. If you're good, attach all the battery cables and snug down properly.

Hope this helps.

70-_VOLVO_ENGINE.jpg

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  

×
×
  • Create New...