520 Not charging, saw sparks

[Justinc 8]

Hey everyone, Merry Christmas.

 

I recently noticed that my 520 wasn't charging the battery and the volt meter was only reading 12 volts, 10 or less if the lights were turned on so I started to do some reading and checked the obvious. Cleaned all connections on the regulator and elsewhere, checked the main ground, wiggled some things around but still no charge. Tonight I was able to get my hands on the molex connector under the battery tray and noticed one of connections in the plug was burnt, so not knowing what else to do at this point I plugged it back in and fired it up and tried to hold it connected really tight, turns out that when I held tight the connection, the volt meter jumped up to 14ish but i when doing so I noticed some sparks coming from underneath the air cleaner tray so I hurried up and killed the engine.

 

Where do I go from here and what could be sparking? Also, i noticed that the middle 25amp fuse only has one wire going to it on the bottom side, is this normal? I didn't see a broken wire anywhere, its almost as if it came that way. No jerry rigged wiring or shitty splices so I'm not sure what to do about that fuse. Everything has been working fine, until the not charging problem.

 

 

[WH nut 553]

First off the fuse, check closely, I don't remember for sure but some of the fuse blocks have a built in jumper. As far as Charging, it seems you found the problem with the connector being burnt. The sparks under the air cleaner need to be looked at for a chaffed wire. I would look at the regulator connections to make sure they aren't bent and touching the air cleaner housing.

[P3x 54]

I had a recent similar issue with charging on my '93 520H. Sometimes I'd see 13.5-14V then constantly 12V or less and the headlights would not come on. Went through all connections and cleaned, all seemed good. Removed the fuses and the 30 Amp(?) had one contact pitted and burned in places from not making good contact with the female retainers in the block.  One fuse retainer had wires (two White)  connected to only one fuse/terminal position - see photo. 

 

All fuse retainers seemed to lack proper tension to make good contact with the fuse  so removed all retainers from the block, cleaned with Emory cloth, contact cleaner and blew dry.  Tweaked the retainer contacts back into shape so they would have good tension and contact area with the fuse inserted. 

 

Did not have sparking from the air cleaner area but found a wire (Red?) going to the regulator with the insulation chaffed through that would cause a short, Applied Elect. tape and put heat shrink over it. 

 

Charge system has been right below 14V ever since. Lot's of good info and resources on this board to TS 520 Elect issues. 

 

 

Good luck and Happy Holidays!

 

 

[ARK 9]

Sparks = arcing= dirty connection.  You will have to go through all and every connection, remove, clean, clean again, polish, make and break the joints 3x blow out, install.  No dielectric grease, examine all, assemble test as you go with all joints made apply a thin film of grease.  At 12 V all grease is dielectric.  Better yet a blast of WD 40 removes water, vapour and is tidy, a 2nd blast of brake cleaner or contact cleaner.

 

Cooper oxide green ****, rust, old grease, water laden connectors, must be clean.  Dirt often creates a semi-conductor mixed with H20 when an insulator is needed.

[Cable 179]

I agree with WH Nut, "The sparks under the air cleaner need to be corrected"

 

There likely is a problem with the 30 amp fuse socket.  There is an internal jumper between the 25 and 30 amp fuses contacts.  Often over heating has melted the block to the extent a replacement contact will not stay put.  One solution if you find a fault there is to relocate the bad fuse to the vacant slot in the fuse block.  I recommend soldering the wires need to make the jump between the 30 and 25 amp fuses. 

 

Replacement contacts and fuse block are available; block PN is Delphi 12004943, double contact PN 12004563, and single contact is 12020321.

 

Glenn Pettit, a merchant on RS, makes a slip-on cap to cover the fuse block.  It keeps out dirt and water.  I use one on my five 520H tractors.

 

The 9-pin connector should be repaired.  If the nylon shell is capable of holding new contacts, the contacts only can be replaced. I like to use gold replacement contacts due to reduced likely hood of future corrosion.  If you can't get good clean and bright copper on the wire ends, soldering in addition to crimping may be needed. Replace both male and female contacts. The connectors are made by AMP; shell PNs are 1-480706-0 and 1-480707-0. Standard contacts are; AMP PNs 3505501 and 3505471. The gold pins are AMP PNs 3505472 and 3505502.  These are available from Mouser Electronics.

 

Do not use dielectric grease.

[Justinc 8]

Well it's fixed. Cleaned all connections, no more arcing, although I'm still not sure where it was coming from. No bare wires so who knows. Removed the alternator/charging wire from the 9 pin connector and spliced in a bullet connector I had and voila, 14.7 ish volts and all is good.