FatJackDurham 318 #1 Posted July 28, 2018 Well, I used my 520-H for the first time today to mow. It ran great, mowed decently well, had good traction. After mowing, I parked it, went to do a think with a guy in a place, saw a man about a dog, then went to start it again. Nothing. Not even a click. I have the demystification guide, and will go through the wires, but I wanted to ask a few questions. 1) Heat - The battery compartment and fuse box got very hot, with the metal bits too hot to touch. I check and it doesn’t seem like the exhaust gasket is leaking. I would have thought if this was normal. I compared it too the 416-8 and didn’t detect any unusual difference. I noticed that the 520 hood has vents in it, even though the motor design isn’t significantly different. Is heat buildup a common issue for this model? Should there be a f ”firewall” or heat shield protecting the battery and electronics? 2) I understand dust blowin is an issue and that there is a part available here to seal the fuse box. What other common issues does this model suffer from? Electrical I mean. 3) What common fix/modification is recommended by the users here. When it started, it started and ran fine. Only the voltimeter and tachometer don’t work. Are there any common things that should be done electrically to adapt for issues that have come to light through experience? 4) Harness. In another recent post, it was mentioned the whole harness can be taken out and worked on a bench. What you mean by this, is it easy? Is there a particular goal? Share this post Link to post Share on other sites
lynnmor 6,820 #2 Posted July 29, 2018 I have three 520H tractors in daily use for years, so here are my comments: 1) Make sure that the engine fins are free of debris and the grommet around the oil filter is in place. You should look in when the oil filter is off using a flashlight and a mirror. Check that the fan for the hydro is not slipping. I haven't seen a heat related failure except the ignition module behind the flywheel. 2) The white 9 pin connector near the battery is trouble prone and might be your current problem. The 3 relays behind the battery can get corroded sockets. I bought weatherproof relays and sockets that I will use in the near future. The seat switch is a pain in the .... seat sometimes, but that is common on other models as well. 3) Download the demystification guide and keep it at the ready, but there are a few mistakes in it. I keep a spare voltage regulator, relay, fuse block and ignition switch on hand and they have been used a number of times. 4) I see no reason to rip out the wiring harness unless the rats have it chewed up. 2 Share this post Link to post Share on other sites
doc724 924 #4 Posted July 29, 2018 If the fuse box is directly behind the rear cylinder, the terminals in them are toast. Heat causes them to relax over time and will open circuit. Also, since they are unplated brass they are prone to corrosion Grass gets inside and then if it gets wet, you have a nice source for corrosion. Terminal blocks and terminals are available from Waytek Wire or Del City. Buy a good crimping too as well. Glen Petit sells the covers for the terminal blocks. Share this post Link to post Share on other sites
FatJackDurham 318 #5 Posted July 30, 2018 (edited) On 7/29/2018 at 8:41 AM, doc724 said: If the fuse box is directly behind the rear cylinder, the terminals in them are toast. Heat causes them to relax over time and will open circuit. Also, since they are unplated brass they are prone to corrosion Grass gets inside and then if it gets wet, you have a nice source for corrosion. Terminal blocks and terminals are available from Waytek Wire or Del City. Buy a good crimping too as well. Glen Petit sells the covers for the terminal blocks. Can you post a recommended block and terminal type? I have a barrel crimper for the packard type for the rectifyer plug. Something like this? https://www.delcity.net/store/ATC-&-ATO-Standard-Fuse-Block-!-4!way/p_795858.h_795859 Edited July 30, 2018 by FatJackDurham Share this post Link to post Share on other sites
Kurt-NEPA 755 #6 Posted July 30, 2018 You could try one of these http://store.wheelhorsestables.com/index.php?route=product/product&product_id=94 1 Share this post Link to post Share on other sites
FatJackDurham 318 #7 Posted August 5, 2018 Well, the 520 started working again. Not sure what changed. I jumpstarted it and it started, so that means it wasn't a relay. Dunno. I'll keep an eye on it. Share this post Link to post Share on other sites
lynnmor 6,820 #8 Posted August 6, 2018 For a fuse block like original equipment this should work: Fuse Block Corroded relay sockets have been the most problem for me. They can do some funny things and no amount of cleaning seems to improve the situation, only replacement is the real answer. Share this post Link to post Share on other sites
FatJackDurham 318 #9 Posted August 6, 2018 13 hours ago, lynnmor said: For a fuse block like original equipment this should work: Fuse Block Corroded relay sockets have been the most problem for me. They can do some funny things and no amount of cleaning seems to improve the situation, only replacement is the real answer. Yep, it's on the list. One tractor at a time. Share this post Link to post Share on other sites
cleat 4,997 #10 Posted August 6, 2018 I simplify the harness and get rid of most relays. Basically I am converting the harness to what was used on the 1988 and 1989 models. Seem to work much better after that. Share this post Link to post Share on other sites
Watch this Richard 9 #11 Posted August 6, 2018 There's a 9 pin connector that can be very finicky. I have the same connector on my 416 ------- and it get me cursing. I also found some issues with my brake lock sensor. Cleaned mine off with electric component cleaner - and it's fine, now. Share this post Link to post Share on other sites