1998 416C IT Backhoe block heater seems to be intermittent

[Dougie G]

It's -30C hear and it turns over but didn't fire up. I had it plugged in but the block heater didn't work. This has happened before and then it worked after that. I have tried different electrical cords, so I don't think its that. Has anyone had any experience with these?

 

[Billrog]

You may have to replace the cord from the heater there about $15

 

[Dougie G]

You may have to replace the cord from the heater there about $15

The block heater on this machine has a plug on the left side of the machine mounted just above the battery box. It is chrome and has a spring loaded door/cover that says CAT on it. Would I have to replace the cord from there to the heater? Where is the heater located?

 

[Delmer]

yes, you'd replace the cord from the male end inside the cover to the block heater that's in a core plug hole in the block. Sorry, don't know where, you'll have to follow the wire. It's also possible you could get it to make a good connection again by scraping rust off the pins on the heater, cleaning out the female end of the cord at the block, or if the female end is shot cut it off and replace with crimp on electrical connectors, but only if you know what you're doing with the last one.

It's also possible for the heating element itself to be failing, but that's much less likely, and it will go off completely soon if that's the case.

 

[cuttin edge]

Use a multi meter and check for continuity in the cord. There has always been a great deal of debate, but I am a firm believer in unplugging a block heater before you start your engine. My father used to work on trucks for the power commission. One particular driver would start his unit every cold morning without unplugging. Although he could not explain it, that truck would need a new block heater once or twice a year. This failure followed the operator through 3 units over the years, and when new guys took his old units, the problem would stop. And just to make sure, cause everyone can make mistakes, is there any power in your outlet.

 

[Delmer]

I never thought of that, just like shaking an incandesent light bulb really. On the other hand, I almost always start the engine then unplug the cord, and have never had a heater fail that I know of.

 

[cuttin edge]

I'm talking starting it, and leaving it for half an hour

 

[Dougie G]

@Delmer I will try following the wires tomorrow to find out where the block heater is and check the connections. I got the machine running today. It didn't want to start, too cold. I left the boom up so I can take the covers off in the morning. Its supposed to be cold again tomorrow. @Billrog mentioned the replacement cord is $15, is that from CAT? I will check the continuity as well.

 

[hookedondiesel]

Canadian tire should also have these cords.

 

[Dougie G]

Update, the block heater doesn't seem to be working at all. so it must be the element. @kshansen Hello, do you have any info on these? This is a factory installed block heater. Thanks

 

[hosspuller]

One particular driver would start his unit every cold morning without unplugging. Although he could not explain it, that truck would need a new block heater once or twice a year. This failure followed the operator through 3 units over the years, and when new guys took his old units, the problem would stop.

I always unplug before starting ... Cuz I'm afraid, I'll forget the cord and drive off... Besides, I'm lazy and don't want to climb down and back, when I can unplug, store the cords, climb up one time and drive off.

As for the op failures... I surmise the engine has air in the block. When at rest the heater is covered, but when running, slugs of air or cold coolant hit the element. Repeated extreme temp swings eventually causes the failure.

 

[Billrog]

Doug before pulling the block heater check it with a meter if there's no resistance then it's toast. At the block not the end of the cord.

 

[kshansen]

Update, the block heater doesn't seem to be working at all. so it must be the element. @kshansen Hello, do you have any info on these? This is a factory installed block heater. Thanks

Not sure if Cat lists spec's on the block heater elements, I'll have to take a look later, but the ones we had on out somewhat bigger machines always tested around 9 to 10 ohms when measuring across the two pins the cable slips over. Also just to be safe I always also checked from each pin to a good ground on the engine block. There you should have infinite ohms/open no conduction at all!

I would expect your's to be somewhere in that same range.

Well could not find anything for you machine but found one machine where it gave some spec's that one was a 1,000 watt heater where ours were 1500 watt heaters. So then I went to a ZeroStart online catalog and looked up what the suggest for a 3054 Cat engine which is what I believe you have. They show one rated at 600watts.

So next you go back to high-school science class and do some work with OHMS LAW, well actually I did cheat and find an online calculator!

Punch in the 120 volts and the 1500 watt of ours and it comes up with 9.6 ohms very close to what I remembered.

Next punched in the 600 watt rating for the Zero Start 3054 heater and it comes out to 24 ohms. So that is what I wold expect to see on yours.

Now if by chance your's is rated at 750 watts then 19.2 ohms

And if anyone has one of the 1,000 watt heaters they should show 14.4 ohms

 

[cuttin edge]

I had an old Jeep with a lower rad hose heater and it worked really well. Not sure if you could get one for your machine or not. Probably just goes by hose size.

 

[Delmer]

Check the continuity of the two pins sticking out of the part that's actually mounted in the hole in the block. There's also a ground pin there, it should be easy to tell which is the ground by the layout of the pins. If it's 400 watts (common for block heaters, the tank type are much bigger) then you'll be around 30 ohms, as long as the ohms is anywhere in that range it's fine. if it's burned out it won't have any continuity, thousands of ohms. I'd plan to replace it with another one just like it if it is burned out.

 

[kshansen]

Check the continuity of the two pins sticking out of the part that's actually mounted in the hole in the block. There's also a ground pin there, it should be easy to tell which is the ground by the layout of the pins

Won't say there isn't a third pin on this machine but all the bigger Cats I worked on the ground connection was via a thin metal tab on the outside of the rubber plug that had the two power contacts. It just made contact more or less in the bore of the hole the other contact pins were recessed into.

Guess I worked on too many big machines cause 400 watts would not be enough to keep my coffee hot on a cold morning here in NY! Our 769C and 769D Cats had two 1500 watt heaters, one for each bank of the engine. Usually only one was needed but we did plug them in at the end of shift and let them set all night under power, 10 hours working hauling stone and 14 hours waiting for next days work on the cord!

I think the only time I plugged both heater in at the same time was if we needed to start one up during winter shut down to bring it in for some repairs. Seems like they could never think far enough ahead to let us do it overnight! So it was plug two block heaters in and drag out a pair of battery chargers usually threw knee deep snow and then go out every hour or so to see if they would fire up! Then bring it and park in shop with box up and hope when the ice melted and came out of the box no one was near by! Made sure tool box was not in the way!

 

[Dougie G]

It was colder today so I didn't work on the block heater today.
I had changed the thermostat on this machine recently, and I noticed coolant leaking around the bolts on the thermostat housing. Its not leaking too bad but will need to be addressed. I put new a new o ring and gasket in when I put it back on. The housing is plastic so I just snugged up the bolts. Don't know if they should have been torqued. One of the o ring type rubber gaskets wouldn't stay in place when I was putting it back on so put a small amount of gasoline on it to hold it on while I put it in place. Maybe I just need to snug the bolts up a little more?

 

[Dougie G]

Won't say there isn't a third pin on this machine but all the bigger Cats I worked on the ground connection was via a thin metal tab on the outside of the rubber plug that had the two power contacts. It just made contact more or less in the bore of the hole the other contact pins were recessed into.

Guess I worked on too many big machines cause 400 watts would not be enough to keep my coffee hot on a cold morning here in NY! Our 769C and 769D Cats had two 1500 watt heaters, one for each bank of the engine. Usually only one was needed but we did plug them in at the end of shift and let them set all night under power, 10 hours working hauling stone and 14 hours waiting for next days work on the cord!

I think the only time I plugged both heater in at the same time was if we needed to start one up during winter shut down to bring it in for some repairs. Seems like they could never think far enough ahead to let us do it overnight! So it was plug two block heaters in and drag out a pair of battery chargers usually threw knee deep snow and then go out every hour or so to see if they would fire up! Then bring it and park in shop with box up and hope when the ice melted and came out of the box no one was near by! Made sure tool box was not in the way!

I checked ohms, there's no continuity so I will need to order a new element and rubber boot. There are three wires. Looks kind of hard to get at and I'm not sure how it all comes out. A schematic would be helpful. It has a fairly heavy cord going to it. It's not you hardware store special.

 

[kshansen]

First off did you check for the ohms at the heater and not just on the contacts under the chrome "Cat" spring loaded door? You need to test right at the heater where the white and black wires are connected. Those are the "HOT" wires from the plug in the chrome receptacle. The green wire is the ground not sure if it is connected to the heater or a ground point on the engine block.

If you do test as above and still get no reading a couple things you need to do. First you need to drain the coolant from the engine. Second I would wait to remove the old on till you have the new one in hand. Looking at the first picture I'm not sure what that chrome threaded thing coming out of the brass fitting is. It could be a set screw to lock the heater in the correct position many block heaters have to be installed in a correct orientation to avoid hitting something inside the block.

It could be that you need to hold the hex part the blue plastic the screw terminals are molded into and use a second wrench to turn the brass part the plug or set screw is in to avoid damaging it.

I tried looking for information on SIS and it would help to have a full serial number as the heaters I was seeing do not look like the one you pictured.

 

[Dougie G]

First off did you check for the ohms at the heater and not just on the contacts under the chrome "Cat" spring loaded door? You need to test right at the heater where the white and black wires are connected. Those are the "HOT" wires from the plug in the chrome receptacle. The green wire is the ground not sure if it is connected to the heater or a ground point on the engine block.

If you do test as above and still get no reading a couple things you need to do. First you need to drain the coolant from the engine. Second I would wait to remove the old on till you have the new one in hand. Looking at the first picture I'm not sure what that chrome threaded thing coming out of the brass fitting is. It could be a set screw to lock the heater in the correct position many block heaters have to be installed in a correct orientation to avoid hitting something inside the block.

It could be that you need to hold the hex part the blue plastic the screw terminals are molded into and use a second wrench to turn the brass part the plug or set screw is in to avoid damaging it.

I tried looking for information on SIS and it would help to have a full serial number as the heaters I was seeing do not look like the one you pictured.

I tested the continuity at the element it self, numerous times, and got no continuity, so I guess the element is fried. I also tested the ground and it seems to be grounded. I also switched my multi-meter to ac and plugged my electrical cord in and tested the black and white wires and got 125 amps at the heater. I am not sure how it comes apart yet. I will not take it apart until I have a new one in hand and know how it comes apart. I will have to price it out at the CAT dealer.