Glow Plugs

[NoTrespassing]

A very interesting thing happened today when I started the tractor for the first time in over a month. The glow plug indicator lit up, stayed on for about two seconds, and everything seemed to work perfectly. The outside air temperature was 40 F. I guess for now I'm not going to do anything but use it.

Does anyone have any idea why it would work now in cold weather when it hadn't come on all summer? Is this normal operation? I remember the same thing happening last year and I thought I had lost the glow plug then too until cold weather set in and it started working.

Kevin

 

[3930dave]

OK, assuming this gplug timing is different than it used to be, I would:

1) Get a schematic for your model, that details the glow plug circuit. Post the schematic here if you can get one; that will help stir up more diagnostic comments.

2) Check the physical integrity of all the related wiring - harness, fuse holders, grounds, ignition switch. Take a close look at your battery terminals and cables. Any sign of corrosion or suspect connections, take apart, clean, re-assemble and coat with dielectric grease or your preference. I don't know what the implications of having a battery disconnected on your model are - I personally would be willing to disconnect a battery on a '99 tractor if it was mine, but don't want to create a false impression of knowledge I don't happen to have :laughing:.

3) Note on the schematic where the GP indicator light is being driven from. If it is on the output side of the GP relay, then perhaps the relay is going south on you. Assuming that the GP relay is the lower cost item (compared to the control module) consider getting a relay to test with. I just bought 2 for my truck (it takes 2) to have as spares from Crank and Charge off Ebay. Not sure if they do Ag stuff, but their prices are good and they give you a warranty.

crank-n-charge on eBay

Nothing against OE, If Kubota's price is not crazy for a GPR, that's the way to go.

4) You need to be able to compare to another similar tractor, or get ON timing vs. temperature specs from a Service manual to really know if the control module/timer is working properly. If everything else checks out fine, and you still seem to be getting very narrow or inconsistent ON timing for the GPs, then you may need a new control module.

Rgds, D.

 

[KennyV]

A very interesting thing happened today when I started the tractor for the first time in over a month. The glow plug indicator lit up, stayed on for about two seconds, and everything seemed to work perfectly. The outside air temperature was 40 F. I guess for now I'm not going to do anything but use it.

Does anyone have any idea why it would work now in cold weather when it hadn't come on all summer? Is this normal operation? I remember the same thing happening last year and I thought I had lost the glow plug then too until cold weather set in and it started working.

Kevin

The glow plug timing circuit turns on the relay Depending on how Cold the temperature is... that is Normal.

 

[NoTrespassing]

The glow plug stopped working all together a few weeks ago. The electric fuel shutoff stopped working last summer. I had the place I bought the tractor from pick it up to work on it last week. It turns out the terminals in the fuse box had rusted from the back and they replaced that one holder with a seperate one. That fixed both problems. They also changed a couple hydraulic hoses on the loader and changed the oil and filters. I haven't got the bill yet.

 

[3930dave]

Thanks for the update, and glad to hear it's fixed.

I more commonly see that type of fuse panel problem on road-going vehicles - do you do a lot of road travel, or otherwise deal with a lot of salt ?

I'm a fan of keeping electrical connections covered in grease or equiv. Looks messy to some people, but automotive wiring seems to be self-destructing at an even faster rate these days, so I'll keep my messy grease :thumbsup:.

Rgds, D.

 

[NoTrespassing]

It doesn't see any road use and no salt. It is 14 years old though and sits outside quite often. The bill was a little higher than I thought it would be, over $800. I probably could have done all the work myself for under $300 if I'd known it was the fuse box. Oh well, it's done, there's snow on the ground now and I'm glad it's fixed.

 

[3930dave]

Amortized over 14 years, that's not too bad at all.

The Important thing is that you now have a solidly working tractor back ! :thumbsup::thumbsup:

There are some optimal greases to use (dielectric, etc.... somebody on here has a favourite one out of the Telecomm world.... just can't remember the name.......) , but IMO, even if you use nothing more than a basic lithium grease to coat 12volt connections, you are doing your vehicle a big favour.

If your relationship with Murphy is the same as mine, now that your tractor is back to 100%, you won't get much snow the rest of the Winter. Your neighbours will thank you !

Rgds, D.

 

[KennyV]

There are several good brands of dielectric silicon greases... if you are looking for the best quality & quantity this one pound can is going to be a Lifetime supply for Most folks... I use a Lot in medical electronics.
Jet-Lube Silicone DM Dielectric Grease, 1 lb Can: Amazon.com: Industrial & Scientific
KennyV

 

[NoTrespassing]

Well...I went out to plow the 8-10 inches of snow this morning and the glowplugs didn't come on. It still started after extra cranking, luckily it was 34 F. out. I guess I'm going to have to call the dealer on Monday. I'm pretty disappointed considering I just sent them a check for over $800. I'm hoping to not have to pay transportation costs this time. Actually I'm thinking of trying to just get away with paying only for parts they put on it and hope they comp the labor. We'll see, I'm glad it started this morning or we'd be stuck on the property until I got it running.

 

[3930dave]

There are several good brands of dielectric silicon greases... if you are looking for the best quality & quantity this one pound can is going to be a Lifetime supply for Most folks... I use a Lot in medical electronics.
Jet-Lube Silicone DM Dielectric Grease, 1 lb Can: Amazon.com: Industrial & Scientific
KennyV

I've been using Permatex, but I gotta say, that is a great price ! Thanks for mentioning it.

Rgds, D.