HI guys I have a Cat 301.7d cr. I have a great wiring schematic. Everything makes sense except the glow plugs. It shows power from the ignition switch directly to the glow plugs and a tap to the glow plug light. No timer or relay. The excavator isn't starting that well. The light only stays on for less than a second. Any ideas.
Schematic sucks Somewhere along red line is one of these Found here on machine It's all automatic.
O man....thanks so much. I was going crazy. Now that you pointed out this timer brain box. Is it affected by temperature also.
It is simply a timer. Every engine start, whether hot or stone cold, triggers this timer, which, in turn, activates the glow plugs (and glow plug lamp). Can't find the specs on this particular one, but, the HCO108 is 6 seconds.
So this one is turning on for around 1 second. Is it burnt out. The manual says it should be 2 seconds. It never starts on the first or second attempt. I had a takeuchi that was the exact same size. Started first time everytime but the glow plug stayed on much longer. Is there different model timers for the cat with a longer time that I can plug right in?
Are you sure that the problem isn't elsewhere? All of my Yanmar powered Takeuchi machines do NOT need glow plugs/ preheating to start normal at temperature down to the freezing point. They all require manual preheating, which no one ever does, unless it's darned cold outside. The lamp working doesn't verify that the preheat is actually working. Have you actually tested the glow plugs? How many hours on machine?
This machine is a cat 301.7dcr . It has 2600 hours. I'm waiting for a nicer day to work on it. The glow plugs look deep in there. From what I can see I have to take the intake manifold off in order to get at them. Little bit of a pain in the ass. I'm going to try and get my probe in there and see how long it says at 12volts. I never had to check the takeuchi because it started so good.
So Cat said the glow plugs are controlled from the ECM. Which changes the delay depending on the temperature. Does that mean it's using the engine coolant sensor?
The extreme very first thing to do is both determine if glows are firing at all, then determine if one or all of them are bad. That is very simple with a meter and some knowledge. You can look at a GP control until you are blue but if glows are not good, you are SOL. Don't even waste your time pulling them to check, a meter will tell the story.
Ok...sounds good. Thanks.
All those smaller machines went to an automatic application of the glow plugs and all of them didn't run long enough to allow for the engine to start on cold days. I had tons of issues with them on trade in machines of that time period. I suggested to several customers to find a way to put a manually operated button bridged into the plugs and their problem would be solved. I don't know if anyone did that.
The manual says it should stay on for 4 seconds. It barely does one second. The finning guy said it varies on temperature which is controlled by ECM. I think you're right. It's just a preset short delay. I wish there was a proper wiring diagram. I'm gonna buy a extra timer and smash the original open to see how it works. I will put a manual push button though. Definitely would make it easier.
Unless your machine has an ambient temperature sensor on it as well......... Seeing as you never supplied a Serial Number it's hard to answer. A quick look at a generic 301.7D reveals that it doesn't have an ECM so I call BS on what Finning told you. Post the publication reference of the manual you have for your machine please.
Cat3017djlj800731
I don't see ECM in here either.
Confirmed - no ECM. Attached the starting instructions from the O&M Manual. Take particular note of Step 5. EDIT: It could be the starting instructions are written around the electrical schematic, so in that case both of them would be wrong.
I see the positions but the key only goes to on and then a spring load start position. Why does it show the positions but it won't go there.
See my reply above. I would opine that the Operator Manual is written on the basis of the schematic which you know is wrong. The schematic shows a key start switch with a 4 positions, OFF, ON, GLOW, & START. As daft as it sounds maybe the solution would be to get hold of a 4-position key switch, connect Pos 3 of the switch directly to the glow plugs and to the glow plug warning light (as per the schematic), and junk the timer.
Ok the outer ring just pops of and it was in the wrong position. Still it only has two spots. But I noticed the spring load spot goes way further to the last position
Thanks for the reply. I agree.
If you go that route here is the switch Part Number - 373-9762. I got this off the schematic and the Parts Manual for a 301.7D of LJ4 prefix which is different to your machine.
Serial Cat3017djlj800731 OK i took out part hco 119 which I thought was the glow plug timer. Metered it and tried activating it which I think fried it. I plugged everything back in and it won't start at all. Metered glow plugs and there only turning on when the starter is engaged. Seems like I'm getting no fuel. I'm suspecting the hco 119 is the flameout relay. I'm getting no smoke out the exhaust at all when cranking it. Any ideas what I screwed up. Where is the dam glow plug timer. The cable plugging into hco 119 is labeled k8.(see pic)
#4 says "glow plug relay" And #10 on the harness line drawing
Apparently "K8" is the engine stop timer. Are you sure that you didn't fail fuse F3 @ 7.5amp. And, yes, the info on this machine's wiring sucks.
Just checked F3 with a meter. It's good. I have studied all of these schematics and there confusing and I'm an electrician by trade. The glow plug wire is alittle thicker and doesn't match the wires on that supposed glow plug timer plug. It has to hit somewhere else. I've ordered that timer anyway because I suspect I killed it. These schematics contradict each other. When the new timer comes I'll crack the old one open and post what the heck is inside. I'm still stuck with glow plugs that don't turn on unless the starter is on. I manually powered the glows plugs and they were drawing 25 amps so I assume there working great. Even when I did that it wouldn't start.
What the heck is this section on the schematic.
Just curious why you think F3 would stop it from starting. What does F3 connect to other than the alternator. The schematic has a dead stop in this area.
First thing to do is test that relay you think you fried. Appears to have 4 wires. That is likely a dry contact, N.O or N.C., then ground and hot for the coil. Can you find resistance? Can you verify supply voltage from the ECM to that relay? Is it 5V or 12V? You already know 12V on a 5V relay will kill it. . But by looking at the schematic, it appears quite dicked because it shows the ECM supplying power directly to the GPs, and that can't be right. By the looks of the schematic, either the ECM or the manual key would operate the GPs. Obviously you are looking for that phat wire. For 25A, you will be looking for at least 12ga wire.
OMG I think I got it. The piece I thought was a glow plug timer is stop solenoid timer. What it does is powers the pull in coil for 1 second and then the hold coil takes over. It needs to turn off or the coil burns out. The glow plugs are manually controlled by the key switch. I didn't know to only push a bit against the spring of the key. That will turn the glow plugs on. In conclusion I fried the relay that controls the pull in coil. I'll know when the part comes in. Fingers crossed.
The finning mechanics I talked to didn't know about this timer. I found documentation on it in the yanmar book.
Next time that you talk to Fanning, see if there isn't an updated, accurate, electrical schematic.
The guy said he'll send me a pdf with the schematic. I was jumping in joy. 10 minutes later I get the email. Same dam schematic were using. I seriously don't think they have one. When you give him a part # he can look up all the repairs done attached to that part and what they did to troubleshoot it. Pretty cool. Not like he would give me that info though.
I am very familiar with the 2 step FS solenoids. I fail to understand how you "fried" a relay, but I will guess you are a sparky that likes to wire things hot, without gloves, and flips the breaker to "see what ya got".....lol Anyway, I can't tell **** in your schematic but a typical FS solenoid will have the "hold" side powered from a keyed on source full time and the "pull" would be powered typically right from the start solenoid so when you turn the key, you pop the solenoid AND the pull on the FS, and that all disconnects when you let go of the key, unless you live in the hills. If you want to test your theory, you can meter test the coils on the FS. The lower resistance one is the pull coil. All you need to do is turn the key on, 'bump' that lead with 12v, you will hear it click, and give it a crank.
The attached schematic for the previous 301.7C model is a lot better and probably not all that different to the OP's machine.
This relay I suspect is solid state because you can't meter a coil. So I basically i put 12 volt on all the terminals one by one waiting for a click. Let's say I never heard a click. And it was probably a bad idea. It's not confirmed but from the schematic it all makes sense I'll update when the part comes in on the outcome. DEC 29 I Hope.
I will comb the common sense out of you one way or another. That all seems like a bad idea so whatev. Spend'em if ya got'em... Sometimes $100 worth of learning is really helpful and quite a bargain!!! I have told many people, "once you experience the financial debt from your ignorance, you will wisen up fast."
Please excuse my comments. I really gotta realize some day that my sarcasm and humor just doesn't read quite right in text....... I was just giving you **** for doing something we are ALL guilty of! If you want to know how to discharge a CRT capacitor in your arm, follow me.... What I was saying above is if you confirm you have a pull/hold solenoid, you can simply bump the pull side with 12V and it will hold and you can run your equipment to test. It will not be affected by the glow cycle or anything and should shut down just like normal as the pull side is only active during cranking.
Part came in. Purring like a kitten. Problem solved. Thanks guys. BTW tested keyswitch and it does turn the glow plugs on but no rhyme or reason in what position because dash go dead part way past the spring.
Maybe a wear problem with the key switch.?
Just found the part#. Tomorrow find the price. Doesn't look like ebay can save me this time. 373-9762
From my dealer
Not too bad. Thanks.
It was in the first post at the top of page 2.
Oops. Thanks
Here's what inside. Definitely not a standard relay.
Was that done regular or extra-crispy.?
I'd say crispy. If u don't have a schematic don't hook power to all the terminals. Mental note. But now I practically know the whole wiring system because of this.
Where is this price from. I can't find a deal like this.
You're in Canada, HMC is in the US. That price is USD, equivalent to CA$112.39. I have no idea if the price above is inclusive or exclusive of Sales Tax. What are you being quoted.?
$190
Got the switch for 160 plus tax. So it works great. Position 1 dash turns on. Turn alittle more against the spring load and the glow plug light turns on for 5 seconds but it's just an idiot light. If you leave key in that position the glow plugs stay on regardless of the light. I'm guessing that's how these switches burn out. 30 amps going through them. I'm thinking of still putting in a glow plug button so this ignition lasts forever. Anybody that reads this now knows more about this ignition then most finning mechanics.