B7100 HST late model will not start after battery replacement

[ken erickson]

Hopefully someone can direct me to the quickest solution!
My tractor is a B7100hst late model. Today I replaced an aging battery with a new Interstate 51r.
After removing old battery, I cleaned the terminal ends, placed and bolted in the new battery. Installed positive ,then negative cables.
When I first turned the key to the glow plug setting I thought perhaps I heard a spark or something like a fuse blow. Now I have no electrical functions at all, no hazard lights, no hour meter, no glow plug or starting.
Yes, I do have the positive and negative cables on the correct posts. The three fuses that I can see that are close to the back of the key switch are all good. The battery was charged last night and now shows 13.25 volts.

Am I not seeing a fuse perhaps?
What would be the next logical step to trouble shoot?

 

[85Hokie]

There is a fusable link ..... that is what blew - check that down around the starter, inline with hot feed.
Easy to test the continuity from starter to hot side of battery.

Somewhere along the line - placing the new battery in hit the hot side to ground when the key was turned.

 

[ken erickson]

I have a wiring diagram and do not see a fusable link.
Just now I checked for continuity of the negative battery cable, which seems fine as it reads 0 ohms when I go from -negative battery post to any ground point on the frame etc.

 

[ken erickson]

I believe I have the issue isolated. I misspoke when I said I purchased a new Interstate battery. It is actually a refurbished battery direct from the local Interstate dealer. I believe that the positive post is broken internally. I can just barely tap the top of the positive post and I get power, glow plugs work, lights work, starts right up. I can let the tractor idle and after a bit the hazards stop working, headlights stop working, a slight tap on top of the post and power again. In one instance I had power, went to start , and as soon as it pulled amps everything shut down again.

 

[Lil Foot]

Sounds like you've got it, good detective work.

 

[ken erickson]

Sounds like you've got it, good detective work.

Thanks! We shall see, my son works at the tire dealership that the Interstate guy stops at. My son picked up the battery tonight and should have a replacement by friday.

As a side note a good friend of mine that lives in Missouri used to work for his dad who owned a Interstate franchise. I called him and asked how common was it that a battery had a bad post connection internally. His words , “rare but did happen”.

 

[Dave_eng]

Just make certain you are not using any replacement battery cable ends as they can produce the symptoms you describe.

Dave

 

[ken erickson]

Just make certain you are not using any replacement battery cable ends as they can produce the symptoms you describe.
View attachment 55720

Dave

thanks! My tractor still has the original Moulded cables. I spent some time with my ohm meter flexing and moving the un-connected from battery cable and decided it’s in good shape.

 

[85Hokie]

thanks! My tractor still has the original Moulded cables. I spent some time with my ohm meter flexing and moving the un-connected from battery cable and decided it’s in good shape.

Careful with the ohm meter...... a strand of wire will show continuity, whereas it will not allow 1 amp to flow. A poor ground will show continuity - but when a load is placed on it, it will not allow the huge surge of amps to flow down it.

But it DOES show there in no open circuits!

Speaking of batteries..... a friend of my was replacing his son's battery on the son's RX7.... and the battery was somehow charged with reverse polarity ....... cooked the entire circuitry, I was told the parts store paid for everything..... then again I have been lied to before!

Glad you solved the problem!

 

[ken erickson]

Careful with the ohm meter...... a strand of wire will show continuity, whereas it will not allow 1 amp to flow. A poor ground will show continuity - but when a load is placed on it, it will not allow the huge surge of amps to flow down it.

But it DOES show there in no open circuits!

Speaking of batteries..... a friend of my was replacing his son's battery on the son's RX7.... and the battery was somehow charged with reverse polarity ....... cooked the entire circuitry, I was told the parts store paid for everything..... then again I have been lied to before!

Glad you solved the problem!

Good advice, I will keep that in mind when using the ohm meter

 

[Dave_eng]

Good advice, I will keep that in mind when using the ohm meter

DENSO has published a great starter troubleshooting guide for those used to using a multi meter.

I have attached the two most important pages.

Dave