My Tractor Forum banner
Cancel
Create thread New Forums

VOLTAGE STABILIZER TO PROTECT HEADLIGHTS MTD 990

Jump to Latest
1 - 19 of 19 Posts

philhaughn56

· Registered
Joined
·
36 Posts
Discussion starter · #1 ·
Has anyone installed a voltage stabilizer inline with their headlight circuit to protect their lights from a voltage spike from the regulator?
I've picked up two new to me 1976 MTD 990's and there wasn't a working light with any one of them. Given that the cost of a new light bulb can be $40+ having this security just makes sense to me.
Image
 
#2 ·
That appears to be a regulator. It take 10-36VAC input, and produces about 13.5-14.5V output (so it can charge the battery), with an unknown max current.

It will not "stabilize" the voltage in the sense you mean, that is just meaningless marketing babble the added to the description, to get into more search results.

Most likely, your tractor already has a regulator like this. And hooking this device up, between the existing regulator and your lights will only make your lights not work (as it depends on receiving AC input, while your existing regulator already puts out DC voltage).
 
#3 ·
dave_r said:
That appears to be a regulator. It take 10-36VAC input, and produces about 13.5-14.5V output
Click to expand...
Do you have a spec sheet on it to make that claim? To me it looks like it takes DC in. Mind you since it purports to buck or boost, it likely converts internally to AC and then back to DC.

I am not familiar with the MTD 990, but a lot of small tractors utilize a separate AC alternator for the lights.
 
#4 ·
Re-reading it, it looks like what I wrote was wrong, it is some kind of DC regulator, to produce a more stable 12V signal from a DC voltage source that can be anywhere between 10V and 36V.

But I still don't think something like this is needed as that kind of VR voltage spike that kills lights isn't something that commonly happens. Incandescent bulbs are pretty resistant to it, even well made LED's will be.
 
#5 ·
Replace the bulbs and see if they blow. My guess is that they all blew from natural old age years ago and the pevious owner(s) never bothered to replace them. Most people don't mow or do much else after dark on a lawn or garden tractor. I know that many members here do, but the average "Joe Home Owner" does not.
 
  • Like
Reactions: Alien5044 and MARK (LI)
Save
Reply Quote Like Like
#7 ·
philhaughn56 said:
Has anyone installed a voltage stabilizer inline with their headlight circuit to protect their lights from a voltage spike from the regulator?
I've picked up two new to me 1976 MTD 990's and there wasn't a working light with any one of them. Given that the cost of a new light bulb can be $40+ having this security just makes sense to me.
Click to expand...
Isn't it just an 1157 bulb...they cost 40 semolians, now? :oops:
 
#11 ·
So not a $40 bulb but rather the shipping is expensive. No local source?

Have you confirmed whether the lighting circuit is AC or DC? Is it wired to the battery to come on if the engine is not running? If so, do the lights flicker when cranking or does the ignition switch turn the lights off while cranking? If it is wired to the battery and controlled by a separate switch, it is best practice to have the lights turned off when cranking cuz the starter generates voltage spikes. Some folks don't realize that the starter can actually become a generator if/when the bendix does not retract fast enough.

Also, it could be the vibrations that are the cause of the bulbs failing.
 
#12 ·
Sealed beams are incandescent bulbs. Over time the filament gets brittle. Mounted in a tractor frame they are subject to a large amount of vibration, thus failures are most likely due to age and vibration not voltage spikes.

Just as Nouveau RN said, they fail, and no one replaces them.

This protective device sounds more like a solution in search of a problem. Just an opinion without the exact specs for it.
 
Save
Reply Quote Like Like
Discussion starter · #13 ·
dave_r said:
Re-reading it, it looks like what I wrote was wrong, it is some kind of DC regulator, to produce a more stable 12V signal from a DC voltage source that can be anywhere between 10V and 36V.

But I still don't think something like this is needed as that kind of VR voltage spike that kills lights isn't something that commonly happens. Incandescent bulbs are pretty resistant to it, even well made LED's will be.
Click to expand...
Why I went down this rabbit hole is due partly to my brother in-law who is a Case LG nut and he tells me that Case has a regulator/rectifier setup that would prevent spikes from damaging the electrical system. I also had a number of 567 chevy's growing up and they all ran this same delco charging setup that my MTD has and I had very little problems there. I may be thrown off track with the dead lights being as a result of not really needing to replace that of which you don't need however my use for my tractor is more for snowblowing in the dark so having light is sort of a big deal to me.
To make this even longer lets go to the snowmobile world where I have an 04 1M 900cc Arctic Cat with no dc voltage at all. I wanted to run a usb charged Garmin gps unit so I added a 12v ac to dc converter (the same unit you install on your walk behind snowblower to take the flicker out of an led conversion) and also added into the dash a usb connector with digital voltage readout. Every time I run that sled and glance at the voltage it's consistently showing a rock steady 12.5v. Pretty steady voltage in my mind. So what's the risk here you might ask? Well it boils down to:
A - there is very little risk
B - there is some risk that could potentially cost two light bulbs at $34 each.
How would I mitigate risk? Either install a fuse or go with the voltage stabilizer. I just now realized that for my piece of mind a fuse or relay is the way to go strickly based on cost. Chevy does have a circuit breaker built into the headlight switch so Chevy for the win in this case.
 
Discussion starter · #15 ·
Alien5044 said:
Sealed beams are incandescent bulbs. Over time the filament gets brittle. Mounted in a tractor frame they are subject to a large amount of vibration, thus failures are most likely due to age and vibration not voltage spikes.

Just as Nouveau RN said, they fail, and no one replaces them.

This protective device sounds more like a solution in search of a problem. Just an opinion without the exact specs for it.
Click to expand...
Vibration and age DUH!! Hadn't even crossed my mind. When I picked up my 990 last summer I saw she was pretty neglected and needed carb work, generator, regulator, lights and tires. Now that all of that has been dealt with do I even have a problem?? I think you may have talked me off the ledge here. Thanks
 
#16 ·
philhaughn56 said:
my use for my tractor is more for snowblowing in the dark so having light is sort of a big deal to me.
Click to expand...
Keep in mid that reducing the voltage to 12V from the 14ish charging voltage will mean dimmed lights. I would be looking at some sort of LED conversion instead. The other linked thread talked about substituting motorcycle headlamps so there might be an upgrade option that fits the bezel.
 
#17 ·
And that $30+ price is if you buy the lights in the worst possible way, one at a time via mail order.

Buying a batch of bulbs, or bundling them with some other purchase, if you have to get them via mail order, will bring the cost down a bunch... Even finding another retailer where the price for the bulb may be a bit higher, but with lower shipping charges.
 
#18 ·
Save
Reply Quote Like Like
#19 ·
Some of those tractors used a separate AC circuit for the headlights and a regulated DC circuit for battery recharging. If it uses AC the lights are dim at idle and get brighter at faster engine speeds, The problems comes if one lamp burns out.
You may want to check the voltage supplied to the bulbs. Also those bulbs work on AC or DC. If they are AC they can be rewired to regulated DC
 
1 - 19 of 19 Posts
About this Discussion
18 Replies
9 Participants
Last post:
Busted Tractor
My Tractor Forum
posts
4.4M
members
246K
Since
2005
A family friendly forum community dedicated to all Tractor owners and enthusiasts. Come join the discussion about specifications, modifications, troubleshooting, maintenance, and more!
Full Forum Listing
Explore Our Forums
John Deere Forum Craftsman/Sears Forum Backyard Round Table: L & G Tractor Related Topics Introductions Walk Behind Mowers