1812 electrical
 

Just a placeholder before I can trouble shoot this, but my 1812 ignition switch isnt working.

First, the oil light wouldnt come on with the key turned. Pressing and pulling sideways on the back plug and it would come and go. So seemed like a connector issue.

Got it in a happy spot and even then the solenoid would click click click before after about 10 attempts it would catch and turnover.

Now its not doing anything...

I even disconnected it while running and it stayed running! Didnt expect that..., I can take the switch entirely off while running and it keeps running.

Also, once running the switch is no longer turning it off. So basically, the switch does nothing.

There IS a ground wire to the motor (green wire on the motor shroud screw). But I remember one of the tractors had a ground from that same screw to the frame where the firewall bolts down.

This smells like a grounding issue (to my untrained non expert completely unknowledgeable eye/nose....)

Course it was -4 this morning and a high of 7 today. The driveway is scraped 'good enough' until the weather warms - says 40's on Wednesday so that might be a good time to take a look.

Stay tuned as I go through the motions. (have the wiring diagram and its pretty straightforward, just need a coffee and some warmer weather).

(yes, it DOES turn over jumping the solenoid with a screwdriver and does run. Note I havent tried starting it with the switch pulled out - I didnt do that until after it was already running). And was wondering if the connector pins wear out, so maybe I need to pull the wires out of the back of the connector and inspect. But first... grounding. Especially since it wont turn off something isnt cutting out the ignition juice.

Bite the bullet and replace the Ignition Switch, part number: 925-3026.

It is an OEM part and the replacement is a drop in replacement.

BE SURE....to check the connector for any corrosion or discoloration.

:IH Trusted Hand:

The m-18 has a magneto ignition, thus it makes it's own power once spinning.
The white wire coming out of the grommet with the plug wires, on the flywheel shroud is the mag kill wire.
When the switch is turned to off position, that wire is grounded to the switch body and that provides the stopping of the engine.(when the switch is mounted)(grounded)
If you look @ the spade terminals on the switch, you will see one that has a flat
strap that leads to the switch body.

Read the other current posts here on switch/terminal problems.
Replace the switch and either terminal ends, or the short pigtail.
Even if you find another problem, all will have switch/terminal problems eventually, sooner or later.

Edit:
Roland types faster than I:BangPC:

lmao

Both great advice. It is a new switch so started down that path already.

Am going to check that ground wire...

(not the biggest fan of splicing into the wiring harness, would prefer to rebuild the connector but know that is a much trickier task). First thing first is to get the connections all working properly.

Maybe I can do a 'simple' test in cold weather on the ground wire. (white one) Now that you mention it, the switch I have has the usual gang of 5 connectors - but then it has an additional 6th connector that doesnt go into the plug. I have to get home and look, but I think I may have this switch: https://www.amazon.com/Replacement-I.../dp/B002VEKZOE Or something like it, 6 terminals I remember seeing.

Maybe I just have the wrong switch entirely (will go back to the old one and test it....). That would be an easy fix.

I have a complete used harness from an 1811 in excellent shape if you need it. Contact me by PM if you are interested.

925-3163A is the wrong switch, use what Roland posted. Time after time we see someone get a replacement switch off Flea Bay or TSC only to find out that it won't work because the circuitry is different internally. Yep it looks the same on the outside.

There are two different ones for different serial number breaks.

Wire harness (2-Relay System); (Used on Tractors w/Serial No. 750,127 thru 756,999)

Wire harness (Used on Tractors w/Serial No. 757,000 & above)

Been there done that!!

Hope this helps.

Yep, wrong switch. The one I swapped is a 6 pin (have no idea where I got it from, it was just in a box of parts I acquired somewhere along the way).

Will try a new switch and go from there. (and will get the original switch out and properly trouble shoot it)

Once again the path is like so many of those before me....

Thanks for sharing all the knowledge on this site. Makes for an enjoyable hobby! (especially when its 4 degrees out and I just want to scrape the drive, not mess with tractors...!!)

Stay tuned

New switch... no go. (and now oil light is not even coming on)

Replaced ground cable between the motor and frame. It will now kill the motor when the switch is turned off. Progress.

Replaced fuse. (likely blown because the WRONG switch was put on by some dufus...). Now have charge current registering on the meter.

But still just a click click click when trying to start it.

Replaced starter relay.

Vroom. All is good again.

Before I scrap this relay I will test it again, it could be just corrosion on the hookups.

A combination of things, makes me wonder how I used it. Definitely seems negligent care for so many things to be needing attention. Could pretty easily be connections just degraded over time, I should goop them all some more....

Cheers!
:beerchug:

It is not uncommon, when dealing with a tractor that is 30+ yrs old, to have multiple electrical issues.

A couple of positive things came out of this. (A) you got the issue(s) fixed. (B) you learned about diagnosing electrical issues, (C) you learned how to wire and use terminals, and (D) the issues you fixed will last another 30 yrs.


:IH Trusted Hand: