Starter relay fuse blowing

[Jeff D]

We have an MX5000 4WD on our farm, and it's started frequently blowing the 40A Starter relay fuse, especially when cold starting and trying to preheat the glowplugs. While it's an easy replace $3 part, I'm getting frustrated with it.
Any suggestions on where to start looking? I've been told its' possibly a bad glowplug that might be loading it too much? Not sure how to test those so any suggestions there would be appreciated before I give up and either buy the fuses by the gross or find a good local mobile mechanic! I've owned Bobcats' with Kubota diesels and have never had this issue so not sure where to start.
Thanks

 

[1970cs]

How many amps are the glow plugs drawing? Have you ohmed out each glow plug?

Pat

 

[Dave_eng]

We have an MX5000 4WD on our farm, and it's started frequently blowing the 40A Starter relay fuse, especially when cold starting and trying to preheat the glowplugs. While it's an easy replace $3 part, I'm getting frustrated with it.
Any suggestions on where to start looking? I've been told its' possibly a bad glowplug that might be loading it too much? Not sure how to test those so any suggestions there would be appreciated before I give up and either buy the fuses by the gross or find a good local mobile mechanic! I've owned Bobcats' with Kubota diesels and have never had this issue so not sure where to start.
Thanks

Do you have a wiring diagram in your owner's manual which you could post?
I cannot find any legible ones on line.

Do you own a multimeter?

Investing about $30 in two basic electrical tools will make finding your problem much easier.

The multimeter is from Amazon.com

In the picture it is not set at the position you would need to test your tractor.

The test light is sold at all auto parts shops

Testing the resistance of each glow plug is easy with the multimeter.

Dave

 

[Jeff D]

Thanks for the reply...no I haven't done that ( and am not sure how...I'm a good very basic mechanic, but I'm not a mechanic! ) Give me some pointers...I assume attach an ohmmeter to each one at a time, key switch on to see the reading? What should they draw?

 

[Jeff D]

Does the bad glowplug theory make sense to you all regarding this? I do have a test light and a multi meter, and have been able to find an online PDF of the workshop manual, so will keep digging, but if anyone know what they should read that would help. Thanks again

 

[1970cs]

Does the bad glow plug theory make sense to you all regarding this? I do have a test light and a multi meter, and have been able to find an online PDF of the workshop manual, so will keep digging, but if anyone know what they should read that would help. Thanks again

Yes, we have a blue one doing the same thing in the shop. We have one that's drawing almost 27 amps by itself. Ohm testing should be done by removing buss bar and pulling each one, to get an accurate reading. Ohm readings should be single digits at the most and even 7-9 ohm is getting questionable for long term use.

But what we are trying to say is do some trouble shooting.

Pat