Valmet 665 Battery Polarity reversal

Whilst fitting a new battery - one of those 5 minute jobs . I inadvertently connected up the battery wrong. I realsied my mistake when on connecting the negative ( to what was the positive terminal on the Battery I got a spark > I stopped and realised my mistake BUT now the tractor blows the starter switch fuse when the ingnition is switched on before the tractor tries to start . If I disconnect the starter then it does not do it but of course does not start .

I have been told I will have damaged the starter solenoid but is this the case ?. Also as the tractor has a loader I will need to do a lot of dismantling if I have to take the starter off - can \i remover the solenoid for replacement whilst on the machine as I have good access to the solenoid ?

The tractor is a 1997 Valmet 665 and any advice would be appreciated

Thanks

After some deduction the answer was a blown relay which has a diode . This is in the starter / ignition circuit and seems to act as a controller for the rest of the electrical circuit .

I know have a running tractor !

If only in the "START" mode, newer equipment MAY have a diode across the solenoid windings for voltage spike suppression.

If your's is set up like that, the reverse polarity could have shorted the spike suppression diode.

The only thing is, the alternator diodes and voltage regulator would likely get "smoked", too, as well. A shorted electronic voltage regulator could be the problem, if the problem occurs in the switch's "ON" mode.

Another possibility... does it have a manual "kill" knob, or an electric fuel cutoff?

If the fuel cutoff is electric, that solenoid may have a spike suppression diode accross it, too, which could have been shorted by the reverse polarity.

I will look to see in the circuit diagram if there is an electronic voltage regulator shown .

Many thanks

James

Sounds like you just did a little "welding" inside that solenoid at the contacts.

Don't feel bad, we all do it at one time or another. :>(

Allan

What would reversing the battery polarity have to do with welding the solenoid CONTACTS????

Neither the starter NOR the contacts would be polarity sensitive. (The SOLENOID MAY be, if it contains a spike suppression diode.)

Furthermore, welded solenoid contacts would make the starter run all the time, NOT blow a fuse????

Man stated that when the solenoid is removed from the equation, the problem disappears.

I'd just assume there is something left-handed going on in there, wouldn't you?

Allan