Head Lights not working

[Rich A]

Have a 2011/12 Sears LT1500. Model 247.28881 Built by MTD. Some time ago both headlights just stopped working. Also noticed at that time tractor was having some trouble turning over. Always started but just barely. I load tested the battery and it was very weak. Bought a new battery and first couple starts were fine but after a while the new battery had same issue.

I checked the mag. output and AC was over 30v, DC was around 14v while running at normal driving RPM.

There is NO available schematic for this thing anywhere. I pulled the light bulbs out of their sockets and was going to check the wiring and found there was no power feed or control of the headlights (frm ign, or battery) Rather the power to the headlights comes from the engine mag. wiring directly. (which explains why the lights dim or brighten with the RPM?)

BUT the two wires at the light socket (ground and power) are BOTH shorted to ground. How could that be possible if that 12v line is supposedly connected directed to the engine mag. Is this why my battery is alway weak? I've been getting along by manually charging the battery every few uses. I mostly use this thing for plowing snow and maintaining a long stone driveway.

Thanks for any help - I'm puzzled ... Rich

 

[Cusser]

This is from my LT1000, but a 2005 model, but might help

 

[StarTech]

It is common for the headlight wiring to get melted and fused together causing shorts. So that is the first place to look for a short when it comes to the lighting.

And not having wiring schematics is one my main complaints about MTD mowers especially. A lot wasted time hand tracing wiring.

Now there are three versions of this mower as you are missing the last digit. The problem with this is the first one only had a keyswitch and the two later one had the RMC module. So which is it? I can post a general wiring diagram for either version from the 700 series which should be the same. I do suspect you have the RMC version which can be either 7 or 8 wire module which is also needed to be noted.

 

[Rich A]

Star Tech, this is the model number as listed in the owner's manual and the various tags on the tractor itself which is Model 247.28881 It's often referred to as LT1500.

 

[StarTech]

Sorry there got one more digit as there are three versions of this mower.

Either that you got to determine if have RMC module which there is two versions or not.

 

[StarTech]

Okay here is the choice of Schematics

 

[Rich A]

Star Tech ... thanks. Looks like what I have is possibly an early model (2011) with the last digit omitted. It has to be your #1 diagram for the 88810 schem. The others are different, (one is a 19 HP as opposed to my 17.5 HP, and the wiring is different on the other two. Can't thank you enough. Just had a big change in weather here and got down to 3 degrees an had a few inches of snow. As soon as I finish plowing the long driveway I'll be able to use your schem to trace the head light green / blue wires. I "think" the short is in the ignition switch. A few days ago it was 50 degrees and now it's noon and 7 degrees with a wind chill down to below zero. I'm up on a mountain top in a forest on a 7 mile dirt road. Just celebrated my 79th birthday plowing snow. Ugh. Too darn cold in the garage to putz with the tractor today. If I keep a trickle charge on it it'll start fine and run for hours. When it warms up a bit I'll get on this. Meanwhile Happy Holidays ... Rich