Weird heat soak problem

[chris young]

Titan Tin, you are absolutely correct. The starter can be bad, but in order for that to be causing the overheat problem the solenoid must be bad too. Really easy to check though, disconnect the +ve terminal from the starter and check for voltage at the starter side of the solenoid with the key on. If you don't see anything, I'd say your problem is elsewhere. If you want to be double sure, set your meter to DC A and put it in between the starter and the solenoid. (don't try to start it or you'll blow the fuse in your meter) Another easy test is to start the boat, disconnect the starter and take her out. Then there will be no question whatsoever if the starter still gets hot. I also agree with Squaminboards, new doesn't mean good. I'll always take "known working" over new any day when troubleshooting. But at least in this case you don't have to throw any parts at it to get a long way down the road to finding out what the problem is.

P.S. I just re read your post and you say the solenoid is brand new? As in never been in the boat without this problem brand new? If that's the case, I'd say very high probability of the solenoid being the culprit.

[TitanTn]

I really appreciate all of the input and suggestions. You guys are great. Let me try to be more specific in regards to the last two posts:

The remote solenoid is new, but the exact problem existed before adding the remote solenoid. The wiring setup has been the same since I received the boat several years ago. The remote solenoid wasn't used - only the one on the starter itself was used. After rebuilding (which included a new alternator) and having this heat soak issue, I didn't like how the alternator was charging back through the solenoid on the starter. So I put in the remote solenoid. There was already one on the boat, but it wasn't being used. I think the setup is now how it's supposed to be. It hasn't changed the heat soak issue, but now (if the remote solenoid is working correctly) the starter only gets power when the key is turned to "start".

So Wotan and others might be exactly right. The starter could be causing a problem. But since it's basically isolated now and not engaged while the engine is running, and the same problem existed before I started using the remote solenoid, I still think it's something else. I like the idea of getting the boat started and completely disconnecting the starter to see if it happens.

[CJD]

So, do I understand that you have both the remote solenoid and the starter solenoid?

[chris young]

No need for 2 solenoids for sure. I'm not sure what you mean about your alternator charging back through the starter solenoid, if everything is working as it should, that's impossible. I found this basic diagram that somebody kindly posted up on the net that may be of helpPCM wining diagram.jpg

There are other configurations, but in this case I think this is how your boat should wired, basically. Since you have a starter with an integrated solenoid, you can just consider the solenoid shown in the diagram as being part of the starter. As you can see there should be no path to charge through the solenoid. Now in your case, if you have it wired such that the remote solenoid is as it's shown in the diagram and you have a starter with integrated solenoid, and you had the heat soak before wiring in the remote solenoid, then, theoretically it can't be the starter, as the remote solenoid would have isolated the problem. Either there are wires going where they shouldn't, or it's not an electrical problem.

I think you need to get it disconnected after you get it running, that's the simplest way to learn a lot in a short period of time, and, you might as well take your surface temp readings at the same time since you've already got the ir thermometer (lucky bastard, I wish I had one)

[CJD]

I think what he means is that the large alternator charging wire was connected to the large battery cable on the integrated starter solenoid. This is very typical...and is actually how it is shown on Chris' diagram. The battery cable on the starter is just a convenient place to feed the battery without having to run a length of 8 gage wire all the way forward to where the batteries are.

Here's where I get confused. If there is a second remote solenoid, that makes the large cable on the starter integrated solenoid "cold". So where did you route the alternator charging wire?

And, if you do have a double solenoid for starting...that is really not a good idea. Every solenoid has a small amount of resistance. When you are putting several hundred amps through 2 solenoids, the result is a drop in available voltage to the starter AND a lot of heat in the solenoids.

Also, the smaller "start" wire to the solenoid coil draws several amps for each solenoid. This is double what the start switch on the dash is designed to take. You may be cooking the contacts in the key switch...thereby reducing the voltage available to hold 2 solenoids engaged...which will induce arcing in the solenoid contacts. Arcing can fry the contacts in short order. Causing sticking, loss of voltage, and/or a ton of heat.

Remote solenoids, as in physically separate from the starter, are used in many Ford engines. Ford uses an inertial pinion to engage the flywheel. GM has always used an integral starter/solenoid, whereby the solenoid engages the pinion...not dependent on inertia. In neither system should you have 2 solenoids.

[ssa]

My 95 454 has both the integral starter solenoid and the remote one. As far as I can tell it's factory.

[TitanTn]

CJD - you're exactly right in describing and understanding the setup. However, I agree with SSA that the remote solenoid looks like a factory setup. I don't know how it was actually wired originally, but the remote solenoid looks like it's mounted in a factory location.

I do like the new way I wired things because it does only route power to the integral starter solenoid when you're in a crank scenario. However, I wasn't aware that it would take that much power to run the additional, remote solenoid. I certainly wouldn't mind replacing the switch just so I can eliminate it being an issue. I can also wire it so as to not use the remote solenoid.

I did a run this evening on the lake and because I didn't do constant driving, the testing was a little inconclusive. For the most part, everything ran better, but it's still not exactly right. I did have one instance of a time when it wouldn't crank. The bell housing was 127 degrees and the starter was 117. Not really that hot from my thinking. I cooled it down with some water and got it to turn over and start. I'm wondering if these temps are actually normal, but the starter and/or solenoid just can't take it. My new plans are to replace the key switch and to send the starter back to DB Electrical. I'll let them test it and see what it needs.

[ssa]

Titan I'm taking mine out tomorrow to test everything out since I removed my running gear over the winter and want to make sure that everything is good to go. I'll check mine out and see how hot the bellhousing and starter get. I was wondering if its normally rather hot and you wouldn't know because most of us probably don't touch any of that while its at operating temp unless we were to have a problem like your having. The remote solenoid on our GM starters is to insure that 12 volts reaches the start terminal on the integral solenoid. All race cars I have ever worked on always use a remote solenoid before the GM starter. With headers or hot exhaust period on a car/truck the heat will cause GM starters to not work. So you can do one of two things wire through the remote solenoid and insure 12 volts reaches the start terminal or install heat shields like Michael said. But since on our boats exhaust heat isnt a issue you need the remote solenoid. I'm thinking the bellhousing heat may be normal and that possibly your original wiring configuration with the high amp alternator did something to the starter/solenoid. One question I was wondering about from looking at the diagram that you posted on your restoration thread was is your positive cable from the battery connected to the starter directly or through the remote solenoid? Mines connected to the starter and then a feed runs from there to the remote. The remote then returns a 12 volt leg back to the start terminal on the starter when the ignition switch energizes it. Basically its a heavy duty relay.

[michael hunter]

One more thing make sure you are using a high quality relay some of the big box auto stores sell cheap outsourced electrical parts . They look the same but wont last or function correctly.

[ssa]

Ok Titan had mine out for a run today and checked to see how warm the bellhousing and starter were. I don't have a ir gun but they felt to be in the 120 range by comparing them to the feel of the thermostat housing when the engine was around the 130 range.