Truck lights dim when moving plow - Snow Plow Forum - Let's Talk Snow Discussion Forums

LinkBack Thread Tools Display Modes
Old 11-10-2005, 09:05 PM
Junior Member
Join Date: Oct 2005
Location: Iowa
Posts: 20
Truck lights dim when moving plow

I just got a new plow on my truck and noticed that when the truck lights are on and I move the plow in any direction all of the truck lights go dim. Is that normal? Headlights and dash lights. Also the alternator gage moves a lot while operating the plow.
Reply With Quote
Sponsored Links
Old 11-11-2005, 01:54 AM
Join Date: Nov 2003
Location: CNY
Posts: 163
That's normal.

Sometimes when plowing, I need to stop and let the battery recharge for a minute or so. Plowing in lo helps alot, as it keeps the revs up for charging.
Reply With Quote
Old 11-11-2005, 09:48 AM
Junior Member
Join Date: Oct 2005
Location: Iowa
Posts: 20
Truck lights dim when moving plow

Thanks for letting me know. I wasn't sure if something was wrong with it or what.
Reply With Quote
Old 11-11-2005, 10:53 AM
EZSnow's Avatar - Addict
Join Date: Nov 2003
Location: St. Paul, MN
Posts: 1,783
Moving the plow is a high current affair, so it may rob the available power from other accessories. On my last truck, I added dual optima yellow tops and some 0ga welding cable between the batts and to the plow solenoid. After that mod, it didn't dim the lights at all. It seemed to move the plow faster, too.

While dimming lights may not be indicative of a problem, you can probably improve the performance of the system. In my 350, the (aftermarket) voltmeter pulls from upper 13s to around 12 when the plow is running. I haven't noticed dimming lights yet. The diesel trucks run some pretty serious batteries.
2003 F350, 7.3, Erie Special #36
SnowEx Mini-Pro 575
1986 F150 302, 4spd, 35's
Reply With Quote
Old 11-11-2005, 11:09 AM
bud16415's Avatar
Senior Member
Join Date: Nov 2003
Location: Erie Pa
Posts: 909

Welcome to LTS
The pump running draws a lot of amps from the battery that the alternator alone couldn’t supply. In doing so it draws the voltage down for the few seconds the pump is running. The lower voltage dims the lights. The trouble is during these few seconds everything else sees the lower voltage also. with lower voltage comes higher current to do the same work.
Some questions would be how old is your battery? And is it the largest size that will easily fit. Largest also as in cranking amps also. is your alternator original? And did your truck come with a snow plow package? One of the things that provides is a higher amp alternator. Wire size (undersize) and poor grounds can also add to this as they increase resistance to the pump.
If you need more battery now is the time to find out before the snow flies. The colder weather will lower the usefulness of the battery and also thicken the fluid in the pump and make things work harder.

There have been a lot of other posts about up sizing batteries and alternators even ways to run two batteries to help with power consumption. Do a few searches and report back.
2000 2500GMC Classic, Modified Trail-Buster Dozer Blade,
BFG All Terrain A/T KO’s 235-85-16
Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -8. The time now is 11:05 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.1
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.