OK farm tractor mechanics, need advice...

jjmitchell60

Well been having electrical issues with my 1978 Ford 4600SU diesel farm tractor. My battery is near 5 years old, is weak (down from 820CCAs to 780CCAs) but still good enough. It was only charging to 11.64 Volts where it holds at with no droppage but if I charge it with battery charger it will hold a good 12+ volts. I found it was weak when we tested it but still good enough to do the job. So checked the alternater today and all it was putting out was 11.64 volts which is why the battery will only charge to 11.64 volts while on the tractor! So figured alternater was bad thus took it off after I was done bush hogging. Had it checked at parts house and it was charging 15 volts on the machine thus good! So they said the ONLY other thing it could be is the voltage regulater in their opinion. Have a new one to install Thursday. NOW if it (voltage regulater) does not fix the problem, ANY IDEAS as to what else it could be? I can only come up with Battery (weak but good), Alternater (good as tested), and voltage regulater (to try new one Thursday) as to the circuit not counting starter which is less than 6 months old. SO, am I missing anything else that can cause it to only charge 11.64 volts IF the voltage regulater does not fix it????? Can the idiot gauge or wiring cause it?

MBK

Maybe loose fanbelt?

Horse Plains Drifter

How did you load test the battery?

jjmitchell60

Not the belt, it is new and really tight!!! Almost too tight being I like to never got it to fit properly!

retroxler58

jltrent

Just have went through this with a 1977 Ford 3600. Load test the battery or us a bobble test on each cell after charging for a couple hours and see if all cells are good. Also while it is charging see if each cell is bubbling about the same if not weak cell and the cell next to the negative post usually goes first. I had the alternator tested and it tested good, but the bearings were real dry, so I had new ones put in before they went bad and done a lot of damage. I put a voltage regulator on it and it is working well now.

Battery fluid tester.
http://www.ebay.com/itm/BATTERY-FLUID-TESTER-TUBE-STYLE-6-Volt-12v-24v-BATTERIES-/180856774307?pt=UK_Diagnostic_Tools_Equipment&hash=item2a1be75ea3

Battery load tester
http://www.ebay.com/itm/12-Volt-Battery-Tester-Load-Car-Battery-Tester-12v-Battery-Tester-Battery-Auto-/230869863892?pt=US_Battery_Testers&hash=item35c0ea8dd4

Voltage regulator for the Ford 4600
http://www.ebay.com/itm/Ford-Tractor-Voltage-Regulator-D1NN10316A-/180953089888?pt=LH_DefaultDomain_0&hash=item2a21a50760

jimdeere

You have a ground problem. See it all the time.

Mercury

Get rid of that battery. 5 year old batteries are either failing, or getting ready to fail. Especially if they are in the extreme heat or extreme cold. That info was passed to my by a guy who owns a battery factory here in town. He said any battery over 4 years old is just a problem waiting to happen.

Merc

tomahawk

quote:Originally posted by jimdeere
You have a ground problem. See it all the time.

+1

burpfire

i am pretty sure that the battery is junk! did you test the alternator for out-put at the battery or the alt? very common mistake for people to check it at the battery. that is only telling you whats in the battery. test it at the alt. if its putting out more than 11.4 volts, its the battery. there is a way to full field test your regulator, by jumping a couple of terminals together to see if it is any good, but i have no idea without a manual or looking at it.

fishkiller41

bad ground?

jjmitchell60

Forgot to add that I disconnect the battery after I shut the tractor down after use. I know I have a dead short which will drain the battery if I leave it hooked up, the short is in the gauge cluster some where.

As to load test, used teh machine the pparts house has which was what told us the CCAs were down from 820 to 780. Tested the alternater at battery, at the alternater itself, and on the machine at the parts house. All I got at battery and at alternater was 11.63 volts. At the parts house they got 15 volts.

As to new battery, most likely will replace it anyways being it is weak but need to find the charging problem first.

I appreciate all the advice. On the bad ground, would you say the bad ground has to be in the charging loop? IF so, then it is either at the starter where one ground is or at the regulater. I cannot find any otehr ground that would affect charging. Looking at the schematics, I find no other grounds that will do it. So will check teh grounds as well Thursday.

Again thanks to all.

fordsix

regulator[^]

wundudnee

I would also guess the regulator. One cheap thing to do is go over the whole charging and electrical system and clean every contact. Clean, bright and tight. Don't cost nuthin and it might help.

slumlord44

First thing I would do is find and fix the short. Second is replace 5 year old battery because it is 5 years old. If there are still problems replace the voltage regulator if it is not putting out around 14 volts. I have found that most of these electrical problems are a bad battery.

Mobuck

It's not that hard to remove the 4 screws holding the cluster in the cowl. Either fix the short or disconnect it before it sets the tractor on fire. FIL burned an IH when a short arcing against the fuel tank ignited. The ground connection next to the starter is a common culprit for corrosion.
I've owned a 4000 since it was new in 1967(at one time, we ran 3 of them) and have seen most of the electrical problems. Very seldom does the regulator fail in my experience. I run an car battery instead of the ag type original because car batts have a better/longer warranty and higher CCA.

JimmyJack

Wouldnt hurt to check your meter against another one.