Glow plug relay kills battery dead

[Highbeam]

So I've had the unfortunate experience of getting all ready to run the tractor, sometimes after trailering it for 50 miles, and turning the key only to hear nothing. No clicks buzzes or lights. I have a 3 year old Optima style AGM battery and when I checked the voltage with my meter I got 0.20 or very dead. So I jump start the tractor with my truck or even a Honda car one time and everything works great, the battery recharges and the voltmeter reads 14 or so when running after I get back to the truck. The next day it will either start perfectly or it will be deader than heck.

The battery holds a charge when disconnected, the alternator charges just fine, and everything works fine when the tracor is running. I must have a short somewhere. So with the key out of the tractor and a fresh charge on the battery, I removed the ground cable from the battery and touched it back to get a satisfyingly large spark. Ah hah! I have a parasite, a leak, a short.

I've been having some glow plug issues over the winter where sometimes I get no GP action and the only thing other than a short that would suck so much juice is the GP system so I traced the GP wire from the head and it is a black wire with red stripe. I found the relay on the firewall with a black wire and red stripe and unplugged the relay. No more sparky at the battery terminal!

For peace of mind I think I'll do a little more testing on the tractor side of the relay plug to make sure that the GP timer is working right. The dash GP indicator always worked like normal. The GP relay plug was not corroded but was muddy inside which is odd since it is so far away from mud.

So is this a typical problem? The relay is easy to remove and replace, can't be too expensive. Does anyone have any other ideas or do you think I found it? On my Ford truck, the GP circuit draws 200 amps so I'm sure the GP system could drain a battery in short time on our tractors.

Oh and the Kioti starts up just fine without the GPs when it is 68 degrees out.

 

[Gittyup]

Should be easy to verify if the relay is working properly. Assuming it's a "normally open" relay, there should be an open circuit measured with an ohm meter across the switching terminals when there is no control voltage on the coil. Then check the voltage on the control coil. There should be none with the key out. If there is voltage, then the GP relay would be closed as expected, measuring a short across the output terminals. In summary:

No control voltage, contacts open: problem likely someplace else

No control voltage, contacts shorted: bad relay

Control voltage when not expected, contacts shorted: timer, switch, or other relay that controls the GP coil voltage is the culprit.

Control voltage as expected, contacts shorted: problem is elsewhere.

Control voltage there, contacts open: shouldn't be the case with a "NO" relay. Indicative of a burned out coil.

You should be able to use jumpers straight from the battery to control that relay to see if it opens/closes as expected. The control coil should also measure low resistance (for all relays).

It strikes me that these relays could benefit from some surge protection, like diodes or at least a capacitor across the coil. High current surges and no suppression is what usually causes relays to fail prematurely. Sometimes you can buy relays with surge protection built in. Some relays might also have as separate Enable control line. But, I suspect that these do not.

 

[J_J]

I believe that the contacts inside the relay are pitted and are sticking. You can put an ammeter in-line with the GP wire and see if it is drawing current. You can take a volt meter and see if you have voltage at the GP. in the off position. If so, the contacts are sticking together.

 

[RavensRoost]

Highbeam, I also use Optima Redtops in various vehicles and equipment and like them. However, I discovered they do not like to be discharged dead more than once or twice anymore than other-style batteries do. I have a current drain in my 79 CJ-5 somewhere that I could never catch/find so I installed a battery switch in line then replaced the Redtop. May or may not be solution for you.

When you are confident you have fixed the root cause, may want to replace the Optima and/or perhaps transfer it to a less critical piece of equipment.

RavensRoost

 

[Highbeam]

Thanks for the responses. I have the relay out and on the bench. It is small and dainty, and doesn't seem up to the demands of the GP job.

I don't want to disconnect the battery every time because if the GPs are truly being constantly turned on then I would expect them to burn out or fail prematurely. Also, the load on the alternator would be excessive. The tractor is about the least critical piece of equipment I have and since I will always have my truck around I can always jump start it if needed. I had a 1974 CJ5 just after high school, loved that 304.

I believe that J_J has the answer. The relay is just gummed up and sometimes sticks on and sometimes sticks off. Sometimes it might work fine. I verified that with the GP relay installed, I was getting a huge draw on the battery. With the GP relay removed, I had no battery draw. I feel confident that the problem is in the GP system and the relay seems the most likely cause.

I can always use alligator clips and try to test the relay on the bench. I might do that. I read 64 ohms between the control circuit inputs which I expected since that load is from the coil. The relay terminals are labeled with numbers but I didn't write them down.

 

[SPYDERLK]

I believe that J_J has the answer. The relay is just gummed up and sometimes sticks on and sometimes sticks off. Sometimes it might work fine. I verified that with the GP relay installed, I was getting a huge draw on the battery. With the GP relay removed, I had no battery draw. I feel confident that the problem is in the GP system and the relay seems the most likely cause.

The relay on my Mahindra did that. I wont trust another one - its a battery killer. I substituted a manual N/O switch.
larry

 

[Highbeam]

To be fair, this one lasted 810 hours without a lick of trouble. If these relays were known to be junk then I would investigate one of the higher amp, and heavier duty automotive style GP relays. Those things are the size of a light bulb and rated for large continuous amperage loads.

If I don't hear any "Kioti Specfic" horror stories about these things then I'll just buy a replacement from Kioti. Sometimes a particular manufacturer specs out an improper part but that doesn't sound to be the issue here.

 

[Gittyup]

Sticking contacts are classic signs that the relay would benefit greatly from a surge protection capacitor or a couple of diodes. The capacitor install is almost full proof. Simply place it accross the coil contacts. A cap. rated for about 24V or above would work. Value isn't so important. This will keep arc-generated gunk from building up on the contacts and the relay will last many times longer. Cheap and easy add on available at radio shack.

Relay function is pretty easy to verify. But, it could be something else, like a stuck timer or switch. Did you verify that you had no voltage on the control coil, but were still drawing current (had a voltage) at the relay output?

 

[SPYDERLK]

Sticking contacts are classic signs that the relay would benefit greatly from a surge protection capacitor or a couple of diodes. The capacitor install is almost full proof. Simply place it accross the coil contacts. A cap. rated for about 24V or above would work. Value isn't so important. This will keep arc-generated gunk from building up on the contacts and the relay will last many times longer. Cheap and easy add on available at radio shack.

Relay function is pretty easy to verify. But, it could be something else, like a stuck timer or switch. Did you verify that you had no voltage on the control coil, but were still drawing current (had a voltage) at the relay output?

Good idea, but be sure to put it across the relay contacts and not the coil. The arcing is across the contacts rather than the "pull in" coil.
larry

 

[Highbeam]

This is one of those relays that by plugging it in, the contacts are all concealed. Not posts on top like on a starter relay. I was able to verify that the control voltage was not present with tractor off by probing the relay connector on the tractor side. When I tested the relay itself on the bench after removal the contacts acted normal meaning the load contacts were not connected and the control contacts had 64 ohms of resistance across them. If I get a chance I can apply 12 volts to the control lead and move the coil back and forth which should make a nice click.

If this was a monthly or even semiannual problem then I would look into fixing it with a capacitor or with a stouter relay but once in 4 years is probably not a big enough deal. I like to stick with OEM as much as possible.

If replacing the cheap relay doesn't fix the GP issue then I will need to dig deeper, possibly into the timer control. The relay is super easy to swap out.

 

[RavensRoost]

Highbeam, if you do decide to modify, one way is to use the existing OEM GP relay to pull in a big one e.g. one for a Ford PS. This way the OEM relay is only carrying the inrush current of the big relay. You can easily go back to OEM set up if need be and the GP relays for PSs are available at most autoparts stores. I did this on my Lister-Petter diesel genny after frying the OEM relay, so modified it at same time I replaced the OEM relay.

BTW, I have relatives in Chehalis, Tenino, Bucoda, and Napavine, almost in your 'hood.

RavensRoost

 

[Highgear]

I was a big fan of red top Optima batteries at one time ( not any more ). I had one that was 3-years old and failed to start my car. Charged it up with my best charger and it would work fine for a day or two. So I took it to the best battery place in Detroit and they charged it on a special charger made for Optima batteries , they also did a load test and said it was fine . Two days later my car would not start . Replaced it with one from another car and all was fine ! So to save a lot of headache git rid of the Optima !!!!!

 

[tommu56]

Don't forget if your battery is low the current through the relay will be higher.

I'd charge battery leave neg terminal off put a dc amp meter between neg post and terminal and see if you have current flow with the key off.
It could be the key switch bad and keeping relay on when its key is off. or some other low current interment load youl have to hunt for.

tom

 

[Highbeam]

As an update. The tractor has been working great with multiple starts over the last few days running the log splitter. I haven't replaced the GP relay yet, been busy working and racing the bike.

My normal DC ampmeter is fused at 10 amps which is fine for a parasite load but not fine for the GP load. So I use the redneck parasite detection system, which is touching the negative lead to the battery and looking for a spark. After the GP relay was disconnected I had no sparks.

I like the AGM (optima, napa orbital, etc.) so much that I put them in my last pickup and now in the wife's GMC. They don't leak, corrode, stink, or anything. The one in my tractor has now survived years of rough use and being discharged completely a few times without giving up. I plan to keep them, can't put a water acid battery back in or it will leak all over like the last one did. That was sure a mess.

 

[Eagleview]

Just a couple of snippets , if a battery gets that flat , it must be recharged with a battery charger , the alternator will not recharge it again to full .

If you use the Redneck method of finding a drain , don't do it after the engine has been running . Hydrogen gas WILL be present and the striking of that spark WILL blow the top off of the battery (and possibly your head) .

 

[Coyote machine]

I have to second what Iron Horse said about blowing off your face or worse doing things the 'Redneck' way. Also- what about just inspecting the relay's contacts and cleaning them if corroded? And then spraying them with some contact cleaner to keep it from happening for a while longer- maybe another 4 years?
Or replace the relay and keep the old one as a fair spare in case the new one smokes out early....

 

[Highbeam]

The relay didn't look to be easy to disassemble. It's pretty dinky like the size of a quarter on each face. The external contacts are clean.

I know there is a proper process for hooking up jumper cables but I always get sparks near the batteries. Hooking up RV batteries too. Haven't blown up yet! Oh and I use the charger to recharge the AGM battery from dead. At first it was overheating the charger but that was because the GP relay was still hooked up and the battery charger was being asked to fire the GP circuit. Once the GP relay was removed, the charger was left on overnight in the "auto" cycle where it tapers the charge rate as the battery fills.

 

[Patches]

The relay didn't look to be easy to disassemble. It's pretty dinky like the size of a quarter on each face. The external contacts are clean.

I know there is a proper process for hooking up jumper cables but I always get sparks near the batteries. Hooking up RV batteries too. Haven't blown up yet! Oh and I use the charger to recharge the AGM battery from dead. At first it was overheating the charger but that was because the GP relay was still hooked up and the battery charger was being asked to fire the GP circuit. Once the GP relay was removed, the charger was left on overnight in the "auto" cycle where it tapers the charge rate as the battery fills.

The correct way to connect "jumpers" is connect the positive cable first and then connect the ground cable somewhere other than the negative battery terminal: a good clean grounded suface of the engine or chassis

 

[J_J]

Highbeam ,

Does your tractor have an automatic circuit for applying GP voltage? I believe that for some reason, that at one time the relay contacts started arcing, and pitting began. The relay needs to be replaced, and perhaps a capacitor put across the contacts to help alleviate the arcing. Some electronics guy may know the capacitor value that you need.
On my Kubota, I hold the key to the left for about 20 seconds, and then turn the key to the right to start.