Mahindra 4110 Glow Plugs/Relay/Controller?

rtimgray · Dec 28, 2015

Since the weather has cooled off, I've noticed that I've had trouble getting my Mahindra 4110 to start. The normal start sequence is to turn the ignition key counter clockwise, at which point the light on the dash for the glow plugs should illuminate. Wait for the light to go out and then start the tractor. Recently, when I do that, the light doesn't illuminate, although I do hear a "click" from the engine compartment which I thought was the sound of the relay starting the glow plugs. The tractor is then difficult to start. I'm afraid that when it gets colder, I won't be able to start it at all.

I had a similar problem a few years ago with my Kioti DK45, and it was a faulty glow plug controller - a little box in front of the fuel tank about the size of a pack of cigarettes. I think it cost about $45 and took just a few minutes to change out, and that fixed my problem.

Does anyone know if the 4110 has a similar set-up? I've looked up parts online at a couple of dealer sites and they show a "glow plug relay". Could this be my problem? Does anybody have experience troubleshooting a problem like this?

Thanks for any advice that you can offer.

Good luck and take care.

skipmarcy · Dec 28, 2015

Yes, it is very similar. The 4110 has a relay timer behind the dash panel that energizes the relay for a certain amount of time, and I believe the relay is mounted on the framing in front of the air cleaner. The controlled power circuit of the relay has a fusible link that feeds it nearby. Knock wood, I've never had any problems with mine in the 13 years I've owned it so no direct help from me. If you haven't figured it out by tomorrow (Tue), I'll go get my shop manual and try to copy the wiring diagram for you and post it here. Right now the weather is screaming outside and I also have a bad case of the flu or I would do it for you tonite. Since you're hearing the relay click out near the engine I would suspect the problem might be between the relay and glow plug rail, or possibly that power feed to the relay.

rtimgray · Dec 29, 2015

Thanks for the quick reply, and I think we're getting weather similar to your (rain is now gone, but screaming wind). It will be at least this afternoon before I'm home before dark and can have a look at it, so don't worry about getting it quickly.

I'll try poking around in the engine compartment and see if I can trace some wires down.

Thanks for the help and hope you get to feeling better.

Good luck and take care.

rtimgray · Jan 4, 2016

I found the glow plug relay - up in front of the radiator. I checked the voltage going to it and it seems like it is getting 12 volts when we turn the key to initiate the sequence, runs for about 10 seconds, then the voltage goes away. On the other side, there is 12 volts coming in all the time, but it never gets jumped to the other side, so I'm assuming I do indeed have a bad relay. Good news is that it looks like it will be an easy swap; bad news, it looks like its going to cost about $75 for a relay.

Good luck and take care.

skipmarcy · Jan 5, 2016

Just make sure you have a good ground on the other side of that circuit that gets 12vdc for 10 seconds - without the good ground the solenoid inside the relay won't work to close the contacts to the other side of that constant 12vdc. If I'm not mistaken, the constant 12vdc wire circuit is heavier gauge than the control circuit wiring. You can jump that ground side terminal of the control circuit to a really good, clean ground and try it again to see if you get the 12v to the glow terminal.

rtimgray · Feb 1, 2016

Just an update and possible closure on this problem (although I'm going to pose a general question in another part of the forum). The cheapest that I could find a replacement relay from a dealer (either over the phone or online) was close to $90. An electrician that I work with said "Why don't you just use a normal relay and see if that works?" So I picked up a $6 12 volt/40 amp relay from Autozone and made some adapter wires (spade connectors on wire) and installed it. The tractor started right up, glow plug indicator light worked correctly, etc. So it seems like it might be fixed, at least for now.

The question I have - and am going to pose in the parts/repairs forum - does anybody know what type of amperage is passing through this relay? That's really my only concern, is that I will burn up the relay or other components in short order if the relay isn't really up to the task (I've only used it a couple of times with no failure, so that's not much in the way of proof). I just thought if anyone else has information on glow plugs in general, they might know how much they draw.

Good luck and take care.

Dave M7040 · Feb 9, 2016

I was doing some research on Mahindra intake heaters ( the one installed in the intake manifold) and recall 58 amps was typical load when activated.
You could wire up two 40 amp cheap relays in parallel and they will each share 1/2 the 58 amps.
Dave M7040

TXMike06 · Feb 10, 2016

Do you have a picture of your relay? Mine is located behind the dash and has a timer built into it. But mine doesn't control the glow plugs just the heater. I'm curious how the 2 compare.

skipmarcy · Feb 11, 2016

The 4110 uses glow plugs only, not an air heater too. The unit in the dash is the timer only that controls the relay on-time, the relay is mounted out near the air cleaner in front of the radiator. The main switched power that the relay controls is protected by a black fusible link nearby, inbetween the relay and the battery. The spec is FLW 1.25, whatever that means, this is what the service manual says. I don't know what amperage rating that is.

Dave M7040 · Feb 11, 2016

After doing a little reading I believe the 1.25 in the spec is the cross sectional area of the fusible link wire in mm. i.e. 1.25 mm squared
The chart below indicates for this car manufacturer a fusible link wire 1.25 mm will be a black color and rated for 80 amps.
This is likely an industry standard but the manufacturers of fusible links want to leave any selection of their products to the engineers who designed the vehicle.
The glow plugs that are not special designs seem to have a resistance of between .5 and 1 ohm which yields a theoretical current draw of up to 12 amps per glow plug or 48 for a 4 cyl.
Rtimgray 80 amps is a lot of current and not to be trifled with. Buying the correct relay would be a good investment to prevent a fire.

The picture of the correct relay on ebay shows very big terminals for the main switched power to the glow plugs which is a good indicaation that significant power is being switched on and off
T462069032 OEM Mahindra Glow Relay Relay Glow Plug 2810 3510 4110 | eBay
Dave M7040