safety switch ohms out, but bad voltage readings

[rigoletto]

heres the scan:


oops- upside down.........

 

[reynoldston]

voltage I find isn't always a good way to find a faulty safety switch or wire. Just because you my get 12+ volts to a solenoid or starter you still need a large enough current to operate them. This is where amperage comes into play. Its like running your starter with telephone wire. I am just a dumb mechanic that has done this for a living many years and love the electrical problems when they come into my shop. Your very first thing you need is a wiring diagram. I don't care who is helping you the manufactures change wires and hook ups some times yearly so how would they know what wires go to what. I know everyone on this forum knows every wire on every tractor that has every been made. Use this wiring diagram like you would a road map. I am going to stay out of this so I hope you the best of luck :thumbsup:

 

[Rivets]

I agree with reynoldston on voltage, it may be there but not enough to engage the solenoid. That is the reason I asked if you have a test light. This will tell means if the is any current at each test point. I do have that picture you posted, but I am trying to find a wiring schematic, through which I can tell how each component is hooked up and which direction the current is flowing. Reynoldston is also correct about wires, have seen manufacturers use wires which are a different color than what is on the diagram. The schematic will also tell me if a switch is NC or NO, which helps to diagnosis if the switch is operating properly. Reynoldston, please don't back out of this thread, we all can use an extra set of eyes on this problem. My guess it is something simple, but because none of us can physically put our hands on this unit, we must rely on the OP to do each of the checks very carefully and paint us a very clear picture of what he sees. If the OP can give me an exact model number tonight, I will try to contact my service tech at MTD for a schematic. Hope he's not off next week.

 

[rigoletto]

sorry for delay-

now, I forgot to mention that I used a multi meter, not a test light, so tomorrow I will try a test light (I didnt know a tast light needs more current to activate it). Also, the model #'s I gave in post #10 is it- no more#'s available. Except the #'s on the engine itself which I heard are useless for the mower "body".

Ray- maybe you didnt mean it but you said [your a dumb mech]- never say stuff like that - youre knocking yourself down with stuff which 1) is not the truth, 2) only serves to lower esteem, which probebly wasnt your intent conciously, but it happens to detriment without one knowing, so keep offering your valubale advice you learned from much experience, cuz right now, I need it.
good night for now........

 

[Rivets]

We need to get a schematic of your unit. On the tag on your unit is the model number 13A667S118? In your two threads many different numbers have been posted and I need to get the right one. Also, do you know the date of manufacture of the unit.

Also, tracing electrical flow is much more accurate with a test light than a multi-meter. We need to know where the flow stops. Once we find where it stops, we test the components at that point to find out why.

 

[bertsmobile1]

I usually take a slightly different route being mobile so oft do not have the luxury of being in the shop & accessing the massively growing mower files.
I use some jumper leads made from 5 amp wire.
In your case I would run a + wire from the battery to the + on the solenoid then a neg wire from the battery to the solenoid to test the solenoid before I go diging into switches.
All of the modern interlocks, time delays and so on can give really stupid looking readings.
As was previously mentioned the only reliable bit of information on a diagram is the type of switch NO or NC
If the solenoid trips when directly connected then try again via the key with & without the earth jumper
if your solenoid only has 1 trigger wire on it then it earths out through the body and being an older tractor there is a good chance that there is enough corrosion around the solenoid to prevent a good earth.
Some solenoids require a full 12 V while others will allow a significant voltage drop and still work, others will only trip with a reduced voltage to prevent owners bypassing safety switches.
No maker actually publishes acceptable voltage or ampage for that matter in their diagrams so keep the DVM for playing with computers & TV's.
Working on mowers I have 2 continuity probes, one has an led so it checks no load the other a bulb & resistor so it puts a load into the circuit

 

[rigoletto]

We need to get a schematic of your unit. On the tag on your unit is the model number 13A667S118? In your two threads many different numbers have been posted and I need to get the right one. Also, do you know the date of manufacture of the unit.

Also, tracing electrical flow is much more accurate with a test light than a multi-meter. We need to know where the flow stops. Once we find where it stops, we test the components at that point to find out why.

ok- first, yes, thats the model # above. The other #'s I posed as you say were for the ENGINE plate. Just thinking that might help. If not, no harm done. I must have gotten this mod # from a tech at MTD years ago as there is no such model # stamped anywhere on the deck/body at all. the year made was 1997 or 1998. manual says 1998 brochure.

Now update - I put a test light on the + post of solenoid and it lights. Then, on the B terminal on switch and it lights. But when I put it on the S terminal and turned the key to start position- Man, I got a quick split second light burst then I heard from the solenoid (it apeard from there) a brrrrrraaaattttttt. Lasted for about 1 second. Happened at the time the light went out. After, no light.

Thanks.

 

[ILENGINE]

Starting to sound like you may have a bad connection at either the key switch, or one of the safety switches. Something you may want to check, on the inside of the terminals like at the safety switches and the key switches, there is a metal strip on the inside of each tab of the electrical connectors. I have seen those tabs break off, and then not make contact with the the spade terminals on the switches.

 

[reynoldston]

You are losing current or as I said amperage, As said before the only way to find something is start with a wiring diagram. What you do is start at the beginning of the start circuit (battery) till you find the problem. Yes a test light is a very simple tool to use but I like the multi-volt meter myself. The wiring diagram will show you what switches are open or closed, positive or negative current. Don't repeat yourself on anything and think what is suppose happen when you try to start the mower and take your time. What I do is take a highlight pen and mark the diagram as I go. Very important that you have the right wiring diagram for your mower because I have seen where the manufacture make changes year to year and model to model. As I said this is my favor type of work and can sure be a challenge some times when a problem comes and goes. Other then a good guess is someone on this forum going to find your problem for you. I guess why I call myself just a dumb mechanic is I am not that good with words and some times upset someone and really don't mean to. I have been doing mechanic work close to 55 years and still like getting my hands into it but now just small equipment and motorcycles.

 

[rigoletto]

ok, guys, I will try my best to follow the diagram I have (scanned) and follow the colors. I will also check the metal strips, like was mentioned. Sheesh, what a pain, but gotta do it,,,,,,,,,,,,,

I wish we had consensus on to use light or multi meter. Light is easier. I appreciate your helps. I wil let yous know what happens.