Cat 303CR glow plugs staying on

[kjrmlr]

I've got a no start conditon on my 303CR DMA 02017. The machine was run out of fuel (don't ask, I wasn't there when it happened). Filled with fuel, changed filters, bled injectors, and still no start. Pulled the glow plugs and found all 3 are dead. I put a test light on the feed and found constant 12v with the ignition switch on. I have a service manual which directs me to the location of the relay and timer, but unless you take the fuse panel out, or electronic timer module out, I don't see any way of getting to a relay if there is even one back there. Anybody have any experience with this? Am I even looking in the right place? Thanks in advance!

 

[Nige]

First thing an electrical schematic is on its way to you. Check your message.

The glow plug relay is located right next to the start relay in the console wiring group. "Some disassembly may be required" to access it. Ref #40 shown on Page 2.

 

[kjrmlr]

Thank you! I actually have a factory service manual with the schematics. Man, that's one big centerfold! I bought the manual used, so maybe the section with more specifics regarding testing/removal/replacement is missing? All I see when I open that cover is the fuse panel and a Mitsubishi electronic timer module. Not sure if that is for the glow plugs or the shut down. I def do not see a glow plug relay. Could it be behind the fuse panel?

 

[Nige]

What is the Cat Publication reference number on the spine of the binder.?
I'm assuming that it is a paper version. Just checking to see if it's the right one.

 

[kjrmlr]

RENR5810 I don't see the console wiring gp in my manual, so that is extremely helpful

 

[Nige]

RENR5810 I don't see the console wiring gp in my manual, so that is extremely helpful

RENR5810 is correct for your S/N.

That illustration wouldn't be in a service manual. It comes from the Parts Manual SEBP3615.

 

[kjrmlr]

Ah, gotcha. Thanks again. I'll be heading back over to the machine tomorrow to see what I can find.

 

[kjrmlr]

Just as a follow up, when I removed the timer, I found that a mouse had chewed through the casing and shorted it out. This resulted in the relay being activated constantly. Thankfully that's all he gnawed on. For some reason, there's no plate or screen under my heater, so that's where he got in. Replaced the timer, glow plugs and relay, and they're now working as they should. Next step is to ensure they don't get in there again. Thanks again for your help Nige!