BobCat 328 won't turn over

[farmhandjoe]

Hello everyone,

I have read through all of the BobCat postings and couldn't find a similar issue so I am hoping someone can shed some insight.

Basically, when the BobCat 328 starts it works fine. Has around 3100 hrs on it.

Usually I put the key in, turn it right and 3 lights come on (upper left (orange) and both right side ones (red)) along with a loud buzzing noise. Then it turns over and away I go.

Every once in awhile, when I go to start it, I turn the key right, I only get 2 red lights (bobcat-key-right.jpg), the upper left orange light does not come on, and then when I go to turn it over, it makes a rapid clicking noise, but the engine won't start.

To ensure the left upper light still works I turn the key left (bobcat-key-left.jpg) and it comes on.

I tested the battery connections and voltage and all is fine there, although when I hooked up a multimeter to the battery and tried to turn it over, the voltage dropped to 3.5v.

Oddly, the external headlights will not go on anymore while this non-starting issue is still happening.

Sometimes if I wait a few days and go to start it, it will work normally, as it should, and then the external lights work also.

This really perplexes me.

Could it be the glowplugs? Relay? Starter and/or solenoid?

Has any one had this happen before to them? Any ideas of what this means?

Thanks for any help you can provide.

Farmhand Joe

 

[SSdoxie]

You say voltage at terminals is fine. What was it? If not 12.5v or more it is low. Dropping to 3.5v is either a very extreme load or battery does not have any reserve amperage. First to check would be remove battery and have it load tested. Any auto parts/battery retailer will do this at no charge for you.

The orange light is the glow plug indicator. Key to left is manual engagement of glow plugs. Not sure if the your 328 has auto pre-heat, but if it does the glow plug light will not come on if the engine temp is already hot enough. This is usually around 90 degrees.

 

[farmhandjoe]

I did wonder about the battery, so I first tried to jump it with the tractor battery running, which produced a louder buzzing noise but it still didn't turn over.

Then I charged the batter for 6 hrs and tried starting it but that didn't help either.

Yes, I will plan to get the battery tested to see if this is part of the issue.

Usually the glow plugs indicator always comes on when I start it successfully.

Thanks for input, I will try the battery issue and go from there.

 

[farmhandjoe]

So far I have determined its is NOT the battery or the battery cables.

I bypassed both of those (with a fresh battery and jumper cables) and it still makes a funny click-clicky noise without turning over.

The quest continues.

Farmhand Joe

 

[SSdoxie]

When you trun key to start position, it sends vlotage through 1 wire that activates the starter relay to engage start solenoid and also activates the glow plug relay and sends voltage back to the orange indicator light. Only common place the 2 circuits are connected is at the ignition switch and through the 1 wire to the relays.
Check output voltage at the ignition switch start terminal when this happens. If you have 12v at the battery terminal of the switch but less at the start terminal, switch is bad. If the switch is OK, then that wire is likely partially broken or grounding out somewhere before it gets to the relays.

 

[farmhandjoe]

Note: I think the main battery is a little low so for all of the tests I am jumping my JD tractor battery to the main starter solenoid and the engine body. This will hopefully eliminate any issues with the battery or the battery cables.

I removed the cover to the starter console and tested the voltage to the ignition switch, it shows 13.6v when the key is in but not turned on. When the key is turned right, 1 position, it then reads 13.2v.

The other item I voltage tested is I think the starter/ignition relay(?). It is coming off of the ignition set of wires. The purple contact reads 12.6v, the orange reads 12.8v and the black reads 0v (see photos).

So, I am not sure where to go from here. I don't think the ignition switch is the issue and I am not sure about the relay, if that in fact is what it is.

The started solenoid seems to be engaging, but with the rapid clicking noise I am guessing it doesn't have enough power to start the starter?

Thanks for your suggestions SSdoxie.

Farmhand Joe

 

[SSdoxie]

Check the voltage at the center (top) post on the switch, marked ST with switched turned completely to right for cranking. This is the power to the starter & glow plug relay.
That relay pictured is a timer, relay combination for the fuel solenoid and is activated when switch in normal run postion.

The glow plug and starter relays are part of the engine harness, will be in the engine or side compartment.

 

[farmhandjoe]

Ok, I have tested the voltage on the ignition switch (center post) turned completely to right, it reads 6.5-7v, not so good I would guess. This would indicate that the ignition switch is bad.

Also followed this white wire to the engine section, found the relay, which eventually leads to the starter solenoid. The resistance from the white wire (before relay) to the white/green stripe wire (after relay) is 77 ohms, with no key in and 0 ohms with the key turned right. The relay seems to work but I am unsure of the 77 ohms reading.

So I thought I would try a jumper test and take a test lead from the 12v ignition switch post and bring it straight to the starter solenoid post where the white/green stripe wire leads to. Hooked up a push switch. Sadly, it still does the clicking noise. I was hoping that by giving 12v to this connection that the engine would at least start to turn over thereby indicating the the bypassed parts were the issue.

I can't see much left except either the solenoide itself, (current is flowing through the solenoid coils but not through the main contacts?), or the starter itself is not working. Although having said that, the radiator fan can be seen turning slightly when it tries to start.

Is there any way to directly test the starter while leaving it attached?

Thanks for your suggestions SSdoxie I appreciate your help.

 

[Fixemall]

Those ignition/starter interlock relays are known to go bad for no good reason. They are around $50 as I recall.

 

[farmhandjoe]

Well, it seems that I had spend way too much time on other potential issues, and not enough time on the battery connection issues.

We had a tech come by and he got it started after re-cleaning & brushing all of the battery & solenoid contacts.

Am still perplexed as to why the tractor battery didn't jump it, but he pointed out 2 possible factors:
1) BobCats are known for needing lots a starting amps and although the tractor battery was fully charged the ordinary car-jumper cables I had did not send enough amps to kick it over
2) putting the positive terminal to the starter solenoid and the negative to the engine block doesn't work because the BobCat apparently has several different grounding spots

Anyway, its working now and I appreciate all of the suggestions from the forum people here.

Thanks!:thumbsup: