Starter is spinning the wrong direction. 1988 Mercury 70 HP

[CHaynes68]

Hi all,
I just replaced my starter. The problem is that when I turn the key, the starter spins counter clockwise. This will not allow the Bendix gear to to climb up and engage the fly wheel. Also, my trim motor does not work either. Is this an indication that the solenoid that the starter is hooked to is bad. It does make a clicking/clacking noise when the key is first turned. I did a direct connect to the starter with a jumper cable and battery outside the system on both the new and old starter. They both spun counter clockwise.

I have a new ignition switch, battery is fully charged, cables are clean and tight, all wires are tightened securely. The problem showed itself on the water, which resulted in a tow back to the dock. Prior to the breakdown, there were no indications of any problems.

I have a trip planned the 8th of July, so I'm going to get the solenoid on the way with the hope it both makes it by the weekend and fixes the problem.

Thank you.

 

[rjb75]

Re: Starter is spinning the wrong direction. 1988 Mercury 70 HP

Silly question-did you remove the battery cables from the battery? Is it possible that you reversed them on the battery when reconnecting them? I did that once and had the same problem with the starter.

 

[CHaynes68]

Re: Starter is spinning the wrong direction. 1988 Mercury 70 HP

Sometimes the biggest problems are because if the silliest reasons. I did check.

I was removing the solenoid and noticed a part below it looked melted and damaged. It appears it is a rectifier. So now since I am making the assumption that melted electronics are not good, I am wondering what the current rating means. Is it how much current the unit can handle before it frys? There is a 16 amp and 9 amp available. Does it matter which one I get?

Thank you

10 minutes later..... It has to be a 9 amp. The 16 amp is not the same thing.

 

[Faztbullet]

Re: Starter is spinning the wrong direction. 1988 Mercury 70 HP

I was removing the solenoid and noticed a part below it looked melted and damaged. It appears it is a rectifier. So now since I am making the assumption that melted electronics are not good,

Classic symptom of reversed battery cables or battery charged improperly as had a new Deka battery a customer purchased that had polarity reversed

 

[JB]

Re: Starter is spinning the wrong direction. 1988 Mercury 70 HP

Starter motors are series wound. They will spin the same direction regardless of polarity. The internal brushes must be rewired (or miswired) to achieve reverse direction. The bendix gear may be stuck or the starter is not getting enough current to drive it up. A new starter doing the same misbehavior as the old one suggests that the motor did not need replacing.

The fact that your PT&T motor doesn't work at all suggests a problem with the wiring for high current loads.

How did you reach the conclusion that all connections in the battery cables are clean and tight? I have seen bad connections of ground cables so tight that the stud sheared off trying to remove them.

 

[Faztbullet]

Re: Starter is spinning the wrong direction. 1988 Mercury 70 HP

Starter motors are series wound

You are correct on as the old motors where wound, the new permanent magnet starters will run reversed if polarity is swapped.

 

[Chris1956]

Re: Starter is spinning the wrong direction. 1988 Mercury 70 HP

Actually the permanent magnet starters will run backwards, if you install the magnet upside down. I had that issue once after cleaning up the starter.

 

[JB]

Re: Starter is spinning the wrong direction. 1988 Mercury 70 HP

You are correct on as the old motors where wound, the new permanent magnet starters will run reversed if polarity is swapped.

Thanks for the update.

 

[CHaynes68]

Re: Starter is spinning the wrong direction. 1988 Mercury 70 HP

JB, I reached the conclusion that the battery cable connections were clean and tight by taking them off, using a wire brush to put a nice shine on them and then tightening them with a wrench. I will recheck the connections again when installing the new parts.

Faztbullet, thank you for the battery observation. I usually isolate the batteries from the boat while charging, and leave the master switch off. However, one of my batteries was not holding a charge well. I ended up needing to add more electrolyte. The low electrolyte problem may have lead to the damage on the rectifier, which just took time (and Mr. Murphy's help) to show up at the most perfect time. I will replace the batteries. I run two batteries and I am thinking dual cycle on both of them. Thoughts?

I appreciate the comments on the starter brushes and reverse polarity. However, the problem started on the water. We had been motoring for about 2 hours no problems. I had started and stopped the motor numerous times during that two hours. The last time, when it was time to head back, I tried to start and there was no contact between the bendix gear and the fly wheel. So, unless aliens were involved, I'm certain the wiring was in the same spots it has been for the past 25 years.

The starter is doing what it is supposed to. I isolated the starter and used jumper cables to spin the starter. It did spin with enough speed to raise the bendix gear to the fly wheel. I was not holding the bendix gear while manually turning the starter. If one does that, it rises nicely with the starter turning counter clockwise. Good lesson learned. :facepalm: I am thinking that the new starter is fine, and the problem lies before the starter.

Thank you all very much for the good information on this problem and possible problems in the future