Oil Pressure Light Blinking

I got as far as getting to the oil pressure switch today. I got the flywheel shroud loose but not all the way out, but I can see it now. I also took a look further at the crankcase breather and I did see some oil under the air cleaner when I took it out. Also some oil dripping out of the vacuum tube for the fuel pump, so maybe it is a bit clogged. Odd thing is that the crankcase breather on my P220 doesn't look like the one in the Onan manual I have. I'm going to try to get it out and clean it, hopefully tomorrow, and also check and clean the contacts for the oil pressure switch. Maybe it's just a bad ground. raying:

Just for kicks, I looked up the cost of a new pressure sensor switch from Toro - $153.04

As far as overheating, I would think once it cooled off it would start up again. Seemed to be running fine until I turned it off to unload leaves.

Chris, neither the oil pressure or head temperature sensors are in series with the ignition on my 520s. The oil pressure switch either lights the light on low oil pressure or runs the hour meter on normal pressure. The head temperature just has a warning light. So, I don't think either would keep your engine from starting. You may want to check your wiring diagram. If it still isn't starting, I would try connecting a temporary wire from the positive side of the battery to the positive side of the coil to see if it starts and runs without all of the safety switches. Then you will know where to go next. LOI (Love Old Iron) was helping someone earlier with a blinking oil pressure light on the Red Square Wheel Horse forum. You may want to search on it, also.

You state it will not crank now. I take that to mean the starter will not turn or is not getting energized. I see nothing in the starter circuit that is tied to the oil pressure switch.
Perhaps to test the oil circuit/system, you can remove spark plugs (to ease compression) and jump the starter. Spin to see if pressure builds to extinguish light. You can place a test lamp on the hour meter - terminal. The hour meter begins clocking when oil pressure switch turns off the light (pressure present) and then completes the ground circuit for the hour meter.
I would guess you have no issues with the oil system. Rather typical 520 electrical bugaboos. Wiggle that silly nine pin Molex connector. That thing is a great source of aggravation!

Well, I think I found the issue, but maybe not the cause. The 30 amp fuse was fried. My voltage regulator has been acting weird for a few years. When running, the voltmeter vacillates between 13+ volts and pegging all the way right (over voltage). Probably time for a new voltage regulator after 18 years of use. Could the run away voltage regulator have caused the fuse to fry? I don't want to do a simple replace and have it pop again.

Thanks guys. Yeah, I started thinking over voltage wouldn't be the issue, but something is amiss with the regulator. Maybe a bad ground? I will try cleaning the contacts and see once I get the flywheel off. The blown fuse "fused" itself to the fuse clip and I just about destroyed the clip getting it out. In fact I've been searching online for a new clip but can't find one like the OEM version. I also don't see it as a part listed on the Toro parts sight.

Anybody that needs a new fuse holder and clips for a 300/400/500 series WH, I found an on-line source. I think this guy may be on here, not sure, but I know he posts over at redsquare. Goes by the name Eldon. Anyway, his site popped up on a Google search. I couldn't find the OEM type fuse holders or a similar fuse box. Most have one positive lead coming into the fuse box where you can then wire individual breakers/circuits off of the single power lead. The WH OEM fuse box has four slots for 4 individual circuits - that is separate power leads into and out of the box. Anyway, here's the link.

http://www.classickitchensandmore.c...r-wiring-harness-fuse-block-wterm-p-1509.html

I couldn't get the flywheel off so I never did check the regulator. I'm going to wire up the new fuse box then see what I get. Doubt the fired 30 amp fuse is the only issue, but we'll see in due time.

Need some help. I had the air cleaner housing sitting loose on top of the engine while I checked and cleaned the crankcase breather (look fine by the way). A few hours later while working over by the fuse holder, the housing slipped off the engine to my garage floor. No big deal except this tube you see in the pic was connected somewhere but I don't know where. It's not the vac hose that goes to the "power meter" on the dash as I see that still in tact. Anyone know where the other end of this tube hooks to? A scan for open ports somewhere did not uncover anything. I don't have an illustrated parts list for the 520 or I'd look it up that way. Thanks for any clues.

[/IMG]

CHDinCT said:

Anybody that needs a new fuse holder and clips for a 300/400/500 series WH, I found an on-line source. I think this guy may be on here, not sure, but I know he posts over at redsquare. Goes by the name Eldon. Anyway, his site popped up on a Google search. I couldn't find the OEM type fuse holders or a similar fuse box. Most have one positive lead coming into the fuse box where you can then wire individual breakers/circuits off of the single power lead. The WH OEM fuse box has four slots for 4 individual circuits - that is separate power leads into and out of the box. Anyway, here's the link.

http://www.classickitchensandmore.c...r-wiring-harness-fuse-block-wterm-p-1509.html

I couldn't get the flywheel off so I never did check the regulator. I'm going to wire up the new fuse box then see what I get. Doubt the fired 30 amp fuse is the only issue, but we'll see in due time.

Click to expand...

*************

Yes--I have met Eldon several times in the past--that 'link' is his daytime gig.

He started doing repro parts, etc. a couple years ago, I beleive.

His work is quality done, and he is a wealth of Wheelhorse info. Woiuld deal with hgim again if he had something I needed, I didn't know he was doing decals, however.

glenn

glenn

Anyone know where the other end of this tube hooks to?

Click to expand...

Chris, there is an air cleaner sensor under the dash. It is square with a 1/4 inch connection for the hose. It also has an electrical connection that goes to the warning light console for when the air cleaner needs to be changed. If you want to see what the sensor looks like, look at component 32 in the electrical system of the parts break down.

300zx said:

Chris, there is an air cleaner sensor under the dash. It is square with a 1/4 inch connection for the hose. It also has an electrical connection that goes to the warning light console for when the air cleaner needs to be changed. If you want to see what the sensor looks like, look at component 32 in the electrical system of the parts break down.

Click to expand...

...and look very hard for it. It is more like a 5/32" nipple for the hose. The sensor is plastic and very very often the weak nipple breaks off leaving a square doodad that doesn't look like it would take a hose. The remnant of the nipple may very well be in the hose you have.
I've had this happen more than once. I made a little brass plate the size of the sensor and drilled a hole where the nipple was and then soldered on a brass tube. This assembly was in turn attached to the sensor with some small screws and nuts thru the inner diameter of the tubular rivets that hold the sensor together. A dab of windshield caulk between the plate and sensor sealed things up and it works as new.

Thanks guys, I found it by tracing the gray wire that connects to the restrictor sensor per the demystification guide. Looks like the nipple is still there. Luckily, when it popped off, the itty-bitty hose clamp stayed on the end of the hose or I'd never find it.

Received the new fuse box and clips yesterday and I'll start re-wiring it tonight. But, looking at the wiring diagrams for the 520, it shows a 15 amp fuse for the lights and accessories. My fuse box had a 10 amp fuse in that slot. Been there since I bought it used in 1996 I guess since I've never changed it. Seems the 520 should have a 15 amp, 25 amp and 30 amp fuse. Do you guys have a 15 amp in the accessories slot? I think I'll pick one up next time I'm at the hardware store. Thanks for your help.

Doh, I started wiring up the new fuse box and am stumped on if it was wired right to begin with. The 10 vs 15 amp fuse is adding to my suspicions. I'm hoping one of you guys with a 520 can tell me how your 30 amp fuse is wired up. I took a cell phone pic of mine before removing the old one, and did a quick drawing of how the wires ran. Seems I have the two white charging circuit wires ganged together and hooked to one side of the 30 amp fuse with no wire to the other side of the fuse - does that make sense? The side of the 30 amp fuse the white wires are terminated to is then connected via a bus-bar type double fuse clip with the 25 amp fuse - in other words, power passes from/to the 25 amp fuse to the 30 amp, or maybe reverse for charging. Here's the cell phone pic.

[/IMG]

So would it make any sense for the 30 amp fuse to not have terminations on both sides? Should one white wire terminate to either side of the 30 Amp fuse? The Toro wiring diagrams do show the charging circit as white wire to the 30 amp and red out to the battery. How can the 30 amp fuse do anything if no current flows through it? Help!