1989 520 HC just quit

[ben06351 19]

So my 89 520 HC just quit. I have a new battery in it and just replaced the Regulator. I had it running on the trailer just checking the gauges on the dash (the tach. is a no go) when she just cut out. The 30 amp fuse by the starter was blown so that got replaced, but now when i turn the key I get NOTHING. The volt meter on the dash is not even moving before it was working fine. The battery is good the starter is good, I'm getting 12 volts to the solenoid, both sides of the fuse and the starter when i have the key in the run position. Any help at all will be greatly appreciated, thanks

BEN

[AMC RULES 37,127]

Did you confirm the grounds are clean too Ben?

Edited November 17, 2012 by 16HORSE THUMPER

[ben06351 19]

Did you confirm the grounds are clean too Ben?

yes everything looks good. I'm thinking its a safety swich or the 9 pin.

[dbartlett1958 96]

^Ben,

^{Check the connector to the Relay as well, near the 9 pin connector.}

^David

[ben06351 19]

^Ben,

^{Check the connector to the Relay as well, near the 9 pin connector.}

^David

What's that look like??

[dbartlett1958 96]

Ben,

The relay is a small black square piece, located near the 9-pin connecter below the battery. On my 416, one of the terminals was corroded nearly off, giving me an intermittent no-start condition.

Good luck.

David

[ben06351 19]

Well I changed the 9 pin connecter and cleaned up the wiring and still nothing. I'm getting voltage to the solenoid but the volt meter is at 0 and she wont do anything, no lights or cranking, nothing. :banghead:

[TT-(Moderator) 1,131]

Is there battery voltage at the ignition switch plug?

If so, is there any power coming out of the switch when it's turned to the "ON" position?

[ben06351 19]

Is there battery voltage at the ignition switch plug?

If so, is there any power coming out of the switch when it's turned to the "ON" position?

Thanks TT I,ll check that next.

[ben06351 19]

Is there battery voltage at the ignition switch plug?

If so, is there any power coming out of the switch when it's turned to the "ON" position?

So TT there is nothing at the switch with the key in the "on" position.

Still nothing. I tested the starter solenoid as per the description at SOI and it checks out fine. So I'm getting power to the starter but nothing at the dash.

My next thought is the PTO safety switches? make sense to anyone else?

When I check the fuses one of them flashes, as in itsmaking the tester blink on and off, that's a new one for me... so I have no idea whats up with that.

Well it's back to the testing. I really need this tractor my its the backbone of my business. My business partner/ Wife to be were trying to come up with a suitable replacement for this beast and came up with nothing. Oh well thanks guys back to work.....

[TT-(Moderator) 1,131]

Without breaking out the schematics for your particular tractor, the wire with the 30 amp fuse should be the main power feed to the ignition switch. It should supply battery power to the "B" terminal of the ignition switch directly - meaning no safety switches in the circuit.

If you trace that wire - through the 30 amp fuse - you may find that it broke / shorted / etc. somewhere along it's path, resulting in the blown fuse you mentioned in your first post.

If you don't find a problem with that wire and it is actually 'carrying' battery voltage to the ignition switch, the ignition switch could be the culprit.

Don't forget to remove the connector from the back of the ignition switch and clean all of the terminals - if you haven't already.

[ben06351 19]

So I found a bad fuse.....one that I checked like three times but anyway now there is power to the dash gauges and lights work, but I turn the key and nothing the volt meter drops to 0 and the lights go out......So that's where i'm at, making progress but still not where I need to be.

[ben06351 19]

Terry this beast has more wiring than my old truck. Apparently the ignition is fine. It looks to me like the power runs down tothe starter via the 30 amp fuse then back up to the dash the PTO switch must be in the way somewhere because if its engaged the tractor will not start.

[TT-(Moderator) 1,131]

If no one else jumps in here before I return, I'll see if I can look at a schematic.

Your HC still has the large Ford starter solenoid-looking relay near the starter, correct?

Meanwhile.......... Check and see if you're getting battery voltage at the ignition coil when the key is in the "on" (run) position.

[ben06351 19]

Yup looks like a Ford Solenoid to me. 12.2 V at the ignition Coil with the key in the run position.

[AMC RULES 37,127]

Not sure if these will help Ben, seems like the area you're refering to though.

[Save Old Iron 1,566]

Ben,

I'm not known as a big promoter of random parts replacement or "guessing" to fix problems, but history on the 520 suggests the fuse holders corrode and produce erratic and random symptoms. I could direct you through voltage checks to confirm the fuse holders are suspect, but as I stated, the contacts in these holders can become erratic - testing OK one moment and then not perform their intended function minutes later. Replacement is much easier than testing.

Troubleshooting with a voltmeter can be misleading at times. Voltmeters draw extremely small currents thru the tested device - most times fractions of a milliamp. A corroded holder can easily pass fractions of an amp but fail to pass 10's of amps needed during real life operation of the circuit.

I would suggest replacing the fuse holders for the 30 and 20 amp fuses before going any further.

Auto parts stores should have 20 and 30 amp versions of fuse holders. Use the 30 amp style holders for both replacements and use the approved 20 or 30 amp fuse in the appropriate location.

A second thought. You mentioned your battery voltage is around 12.2 volts. A lead acid battery should be around 12.6 volts at rest. The difference doesn't sound all that great but the graph below suggests a 12.2 volt reading represents a battery which is between 30 - 40% of full charge. You may want to charge the battery prior to any further troubleshooting.

Another major item to check is a good connection from the battery (-) terminal to the engine and chassis. A battery jumper cable set can be easily clipped to the battery (-) terminal and to the engine block to confirm if the ground path should be investigated further.

I would also suggest removing the grouping of wires on the starter stud and cleaning each of the ring terminals. This will assure the voltage from the battery is not meeting with any resistance from corrosion between the terminal surfaces.

[ben06351 19]

Thank you very much guys the help is greatly appreciated. I'll keep picking away at this there isn't that much left for me to replace. :bow-blue:

[ben06351 19]

FIXED IT!! Thank you everyone for all of your help. It was the fuse holders, they tested fine but they were shot. So now I have 3 new fuse holders, a new 9 pin connector squeaky clean contacts on everything and lots of new wire and neat and clean connecters. :thanks:

[ben06351 19]

BTW this has been an excellent crash course on the electrical system I learned a lot, thank you for all of the old posts that I have read there truly is an amazing amount of really usefull knowledge on this website, and S.O.I. U.

BEN

[JackC 617]

I have had trouble with intermittent fuse holders. It is easy for water to get into them and collect in the bottom and cause corrosion where the contacts are made. Be careful when cleaning the tractor with a hose to avoid getting water into the fuse holders.

A clear plastic cover over the fuse holders would help keep water out. The fuse holders on cars and trucks are covered but they did not include covers on the Wheel Horse tractors that often get cleaned with a hose.

On the plus side, sometimes we can pick up some good deals when people sell tractors that don't work due to problems like that.

[Sparky-(Admin) 21,300]

Who doesnt love a happy ending!

Congrats Ben!

Mike............

[Save Old Iron 1,566]

Great - that worked for you. Thanks for the kind words about SOI U. I have been trying to stay a little light on the posting of new material until YUKU transfers all the site info from the old FORUMER servers. I know it's happening as I have seen it happen to other sites I frequent. SOI U will be next I'm sure.

Hopefully the battery will charge to near 12.6 volts and all problems will be in the past. If you have any further concerns, let me know.

If you still have the old holders, it might be educational to "fillet" them and show the corrosion on the fuse blade clips within the holder body.

[Kelly 1,029]

Chuck didn't say it, but I'm a big believer and user of dialectic grease, every connection I mess with after it gets cleaned or replaced, gets a liberal dab of it, even the blades of the fuses, I put a new 9 pin connector and factory style fuse box in one of my 520's and everything got greased, it helps keep moisture out, so these problems are held at bay, just be sure to use the correct stuff, it can be had at any auto parts store for a few bucks for a tube.

[JackC 617]

"I'm a big believer and user of dialectic grease,"

Good one, especially for those fuse holders.