TC35D starting woes

[jinman]

The problem is that it's not like a straight wire with switches in it. You have several relays along the way, and in the end the operator safety circuit closes a relay that allows continuity to energize the starting circuit.

I would simply offer to scan the diagram and email it to you, but I'm moving my office around and my scanner is offline at the moment. Maybe I can hook it back up long enough to send you the scan. If you will give me your email address in a PM to me, I'll figure out a way to get you more info to help you out.

It seems you have established that all the swithes are working, but there also might be a broken wire or loose connector somewhere. Do you know how to set your meter to voltage and then check to see that all those switches you checked have 12 volts applied when the key is turned on? That's the next step. If they all work, you have to answer the question of whether there is power through them. By the way, the switches provide a path to ground. When the circuit is complete that path enables the operator safety relay to close and energize the starting circuit. Do you know where the relay assembly is? It's under the two-piece cowling below the steering column. Taking that cowling off (actually just the left half) requires removal of two or three bolts on the firewall under the hood and also the ones visible under the steering column. This is really starting to sound like a relay problem to me. What were the circumstances when the failure first occured?

 

[anonz]

Update -The service tech came out and went through all of the items that we discussed in this forum. Still no start. Then after fiddling around some more he tried again and it started. Question to tech - "what did you do to fix it?" - response "I dunno". Great /forums/images/graemlins/confused.gif

Since then the tractor has refused to start about 3 times.

As with all technical issues, the intermittent ones are the worst. I still wish I had some way of isolating the safety circuit from the main circuit. If I can point the service tech in the right direction I think he would go there.

Thanks for the help. Any other ideas will be accepted.

 

[jinman]

This is starting to sound like a wire broken inside the insulation or an overcrimped connector that is holding by the insulation, but wire contact is intermittent. It could also be the relays as I mentioned.

My offer to scan the circuit and email it to you still holds. I don't want to post it here on TBN because to get the proper level of resolution, you need an image larger than the 100 kbyte limit.

I think if it continued to frustrate me, I might rig an "interlock bypass" to go around this problem too. You have to be super careful when doing this, because if you have an electrical fire, you know they will blame it on your circuit. Maybe a couple of well-placed jumpers using alligator clips would do it.

I think I'd be pretty upset over this, and I'd tell my dealer that if he couldn't fix my tractor so it starts every time, he should replace the entire wiring harness. This is NOT a problem you should have to deal with on a new tractor. /forums/images/graemlins/mad.gif

 

[have_blue]

Had the same problem early on with my first Boomer. It was a spade connector under my right fender. My WIFE found it! /forums/images/graemlins/blush.gif