2008 303.5 glow plugs. What's makes them Not work. The light comes on when the key is first turned like a test for all the dash. But it doesn't stay on and cycle the glow plugs. Starts slow.
Just because the lite comes on, doesn't mean they're actually coming on.. You'll have to get a test lite to SEE if your getting voltage TO the GP's.. IF YOU ARE.. take them out of the engine & put voltage to them one at a time to SEE if they are working..
Thanks for the interest. I haven't gotten that far yet. I'm sure they aren't coming on. The light only comes on for a split second when i first turn the key. Like a check engine light on a car. It doesn't stay on for 10/20 seconds like a 303 rental I ran the other day. There isn't any power going through the 5a glow plug fuse. I'd like to dig in a little this weekend and see.
Any chance of a complete S/N just on the chance there is a "systems operation" description that might explain how they work or at least a wiring diagram to point in the right direction. Just for kicks I did look at one S/N Prefix DMY and there is at least a wiring diagram for that one on SIS and it shows both a timer and relay in the glow plug system.
That would be nice to know what components there are and what wires are what. I'm usually pretty good with diagnostics. My serial # is DYM02176
Oops. I do mean dmy02176
Well see if this give you any hints on where to look:
That is awesome. Thank you.
Should I send an address for you to send the check? Just kidding glad to be of some small help.
I cant remember who it was, but I helped someone out ONCE..[lol]. & they were in the Maple Syrup business & they sent me a bottle from their "farm".. MAN.. that was the best syrup I ever had,, Awhile back we had a LONG thread about getting a Perkins started/fixed.. I "won" & told the guy to send me a "pot holder".. lol I think it would be fun to get actual "pot holders" from around the country..?? but that's just me.. I use them daily & they don't cost squat..& easy to ship..
Well the diagram was quite helpful. But I'm still not quite there. The glow plug timer checks out except for one thing. Grd is good B+ is good and key on + is there. The white wire sends power to the glow plug relay but it never quits. Anyway, not the main issuer since the glow plugs still don't work. They big yellow wire on the glow plug relay is dead. Tracing that back through the diagram is...different. I knew that the 5a fuse has no power, that's in the line there somewhere. Getting closer anyway.
We just made some cider. Could send that around the country. But it doesn't really hold up long. Gotta keep it cold or shoulda canned some. That would preserve it.
Do the glow plugs turn on by themselves or do you have to turn the key switch to the heat setting? I'm asking because I saw one series of machines with the auto unit not turn on the plugs unless the ambient temperature was below somewhere around 45 degrees F. They were a pain because it then took a bunch of cranking to get the engine started. I think there was some sort of update for that but don't know for sure. Maybe someone here has the information.
I don't have another key position. I think they are supposed to come on by themselves.
Note: below the numbers in ( ) are the wire numbers on the drawing and if this is like most Cats the numbers are printed right on the wire, say every 4 inches. What I'm seeing from here is the Yellow #10 wire(877) at the relay = the output voltage to the plugs. The red #10 wire(150) should be hot(battery voltage). In the two conductor plug for the relay the white #18(323) wire is always hot(battery voltage) and the timer activated the relay by grounding the white #18 wire (L987) So far have not seen anything indicating that there is a temp sensor in the system, need to look closer.
That's where I was at. Looking like a bad relay. Nothing coming out of the yellow 877 wire. Could it be that simple.
Does the white #18 wire (L987) show as going to ground when key is turned on? Or when key is in start position? Tried finding anything in SIS that explains the operation of the timer, so far no luck. Just checked availability on that relay, Cat does think a lot of them! They are asking $88.53 for that little 12 volt relay, they do show stock in Syracuse and York PA among other places.
Goes to ground in start position.
If it is going to ground in "start" does that activated the glow plugs? If not it is starting to look like the relay might be bad. Hard to be sure from here but .... Don't suppose you could get a quick look at that rental to see what is hot with key on before cranking???
I probably could. I just jumpered the white wire TJ ground. The real clicks and the yellow wire becomes hot. Relay must be alright. The key on circuit coming out of the timer isn't cycling. Only when cranking.
Hi Matt, It looks like the glow plug indicator in the monitor display is taking it's signal directly from Wire 877 F51 this goes through the 5a fuse switching to wire 439 F47 and onto the monitor. So in reality if the glow plug light is coming on in the monitor the timer should be activating the relay. I would check for voltage at the glow lugs when you you turn the key on. If you get a flash the circuits should be OK. The next thing is the logic used in the timer as Ken mentioned. I would assume the timer has the ambient temp sensor incorporated into it. The other thing is that temps here have been unseasonably warm and the timer may not be calling for the glow plugs. Depending on the engine used that could be fro 45-30F and usually it only comes on for a brief time and timer then extends the duration according to decreasing temps. It can be difficult getting that info from the product group if it is not easily available to the dealer. I Have been through that when I worked in Syr. Is your father named Matt as well and lives on South Hill?
Matt the connections on the releay should as below #3 - 200 Ground #4 - 308 Should have voltage with key on #5 - 306 Should have voltage with key in start position #6 - L987 should b e ground when glow plugs are activated. So make sure pin 4 is hot with key on and pin 5 is hot with key at start
By jumpering the ground contact on the relay it makes the circuit work like it should and the dash light comes on with it. I didn't happen to notice if that rental unit had a Mitsubishi engine in it. Mine appears to be. It's got the 3 diamonds logo on a sticker on top of the valve cover. And no. That's a different Matt eaton. Not to far away. I do know them.
Never thought about that, there could be a sensor built into the timer "Brain box"! Well that was a surprise, just for fun I checked the price of the timer # 119-9896 and it is only a bit more than the relay $95.53 and one is sitting in the Syracuse store. Now all we need to do is figure out which one Matt needs. Seems if there is power to one of the white #18 wires on the relay and when a jumper is used to ground the other terminal that has the other #18 wire on it and if that powers the glow plugs that would say the relay is functioning, if not then the relay is at fault. Does that sound right Ben? Just don't want to spend any more of Matt's money than we have to!
OK maybe you're the Eaton's from Cincy way then? I am just over the hill (or 2) from you Does sound like a Mitsu. Like I said depending on the logic/strategy of the glow plug operation it may not even be calling for operation at these temps. Maybe in the next few days it will get cool enough to see if they will come on for longer . Are you having issues getting it started now?
Yeah that's us. Willet. It has always started. But I thought it always seemed sluggish on the cranking and the crank time. I've only owned it a few months. When I used the rental 303 in town it started like a gas engine on a car. Easily twice as fast as mine. And I noticed the glow plug indicator cycling. Which mine doesn't do. I'd like to get whatever I need and a cat battery in it before it actually doesn't start when it's cold.
I think if any thing is faulty it is the timer. But I would rather he wait for cooler weather or Use something to cool the timer down and see if glow plug activation time increases. You could always shoot it with a CO2 fire extinguisher or take it off and put it in the freezer for awhile then try it to see if it works better. Of course I would have probably have to set it in my cooler full of cold beer to do this....LOL
I've just got the two beer fridges. Don't have a cooler out. And I'm not the only one thinking of shooting it with a fire extinguisher. Saw it on myth busters. But I'm not going to do that. Would cat be able to tell me the range if there is one for the temperature
Of course if you don't want to pend $100 or more by the time your done. You can always put in a push button and run the L987 wire to that and the other side to ground. That way you can call for glow plugs anytime you want. Besides that would tell you if you get an improvement in starting with increased glow plug time
I was thinking of that already if it's going to ne an issue. I wonder what just a new battery would do. There is a "Deka ultimate" battery in it. 850cca. Ever heard of that? Looks like a $50 Walmart battery to me. Looks new. Ish.
Maybe. The guy to talk to is Todd. He is like their technical expert. Or at least he was there last I knew. Things have changed quite a bit in 15 yrs. He still may have a tough time getting the info.
How do I really tell if the glow plugs are good. Test light lights up on the connecting post of the glow plugs, when I jumper the ground. Should in be able to feel them getting warm on the outside after 15/20 seconds.
I would think you should feel them but if they are long enough you may not. You can measure them with an Ohmmeter from the connector to engine ground and compare them to each other or I am sure that Cat has a spec for them. You can wait til the morning and just ground the relay for 20 sec. then start it and see what if any difference it makes. Also comparing one machine to another even of the same model may not be an accurate measurement. Engines and systems can change and results will vary
Hi Guys, Its been my experience you cannot test them using ohm meter. What seems to happen to them is the resistance wire in the tip of the glow plug gets thinner over time and even though they measure the correct ohms with a meter, when a current is applied the current draw is way down from original due to the wire being thinner . As a quick test we use a non intrusive amp meter which goes over the main wire as a test. Usually they are wired in parallel so better test is to disconnect each one and apply power and test current draw. A lot of people go around in circles with glow plugs being side tracked by the fact that they are drawing current. The fact is they must have the full design current as they only have seconds to get hot sometimes glowing red hot at the tips. So even half original current affects there performance dramatically. Word of warning if you are applying power manually and your plugs are old and weak they sometimes pop and finishes them off so don't take all day making your current draw test. You mentioned somewhere it was not cranking as sprightly as the rental. The battery, cables, and starter have to be tip top in cold weather. A weak battery will reduced cranking speed and reduce your heat off compression and also supply less current to your glow plugs reducing there effectiveness. Its hard some times to find what the current draw should be and some times you can get it from the plug itself. Good Luck.
Some good points there. I'm getting a timer today so tomorrow morning I'll see if it's any better. Go from there if something else is suspect. Thanks for all the help and comments.
The timer brought the system back to life. Indicator comes on, starts way better. I've tried it a few times so far. Not been super cold but already notice a huge difference. Thanks for the wiring diagram and the pointers.
Don't worry by the end of the week you should see overnight temps in the low 40's to middle 30's! to test those glow plugs! Glad that it seems to be working now!