View Full Version : Electrical problem - semi starts but won't run.

06-21-2005, 11:49 PM
Just bought a 1990 Tristar 220. The voltage guage was running about 10 idle, 11.5 @ 30k rpm. I ran into a couple of instances where when I would turn on the ignition and none of the guages would light up & at the same time the motor would not start. The motor would actually fire up briefly then die. Eventually the guages would light back up and the motor would run. I was told that the alternator/regulator was bad so I replaced it. Now the boat is permanently in the no guages won't start mode. I have read where there may be a nuetral switch and/or a fuse box that needs to be looked at. Does anyone have any suggestions on this? I'm dead in the water on this one!

lakes Rick
06-22-2005, 12:21 AM
One of the guru's should come on here...

I would check all of your grounds.. Take each one off and clean them and where they bolt.. Take battery connections off and clean them..From there I would look at your relays.....

06-22-2005, 12:49 AM
I will re-clean cables- read somewhere that 99% of all electrical problems are due to bad battery connections.

Oddly enough, I was looking at the owners manual & it has an ignition diagnosis chart. The heading for "engine starts but stops when ignition switch is in run position" describes the issue exactly. The diagnosis says to check the ignition switch and/or an open circuit in ignition wire & switch to coil.

east tx skier
06-22-2005, 10:04 AM
Ahunter, welcome. Figured I'd give your post a bump up to the top of the home page so that somebody with a lot more mechanical/electrical know-how than I, i.e., JimN, could offer some suggestions. Good luck!

06-22-2005, 10:12 AM
Spoke with the local folks at Texas Mastercraft - he thinks its the ignition switch - nice guy. I'm sure there is a way to test it for sure.


06-22-2005, 10:22 AM
The iginition panel is pretty easy to remove on my 89 tristar, I would assume it is the same on a 90. 4 small screws. You could pull that out and make sure all of the wires are in snugly in place.

06-22-2005, 03:51 PM
I bypassed the emergency switch and the guages came back to life for a few seconds until the ignition button/fuse tripped. The wires were smoking hot so I knew we had another issue. I went back to the folks that sold me the alternator : arcomarine and they informed me that the new alternator required a little different wiring than the old. To start, the "excitor" wire(purple) does not go on the E terminal as I was previously told but on the "exc" terminal. Secondly, an additional wire has to be run from the regulator to the output terminal so the regulator will let the alternator know that there is fire or something like that. Of course the safety switch evidently was also out so I replaced that as well. Purrs like a kitten for now - hopefully the whole system did not get blown out like the safety switch.
Thanks to all!

east tx skier
06-22-2005, 04:48 PM
Glad you got it worked out.