Is my alternator going bad?
#1
Registered User
Thread Starter
Join Date: Sep 2006
Location: Utah
Posts: 11
Likes: 0
Received 0 Likes
on
0 Posts
Is my alternator going bad?
I noticed this issue when I start my truck cold (I haven't really noticed if it does this warm). When at idle with heater and lights on, the heater seems to slow down speed up, almost like I am changing fan speeds and the lights keep going dim then bright then dim, etc. I noticed the amp gauge keeps fluctuating as well when it does this. Does this mean I need a new alternator? Thanks for the help.
#2
Registered User
Join Date: May 2005
Location: Edmonton,Alberta
Posts: 805
Likes: 0
Received 0 Likes
on
0 Posts
Nope your alternator is just fine. What is happening is the air intake grid heater is cycling, thus putting a load on your alternator and causing the lights to dim and gauge to drop. It's completely normal and every 1st gen does it. I believe the grid heater comes on when it is colder than 50*F(correct me if I'm wrong gurus ).
#3
Registered User
Thread Starter
Join Date: Sep 2006
Location: Utah
Posts: 11
Likes: 0
Received 0 Likes
on
0 Posts
Thanks for the quick reply. I am a bit relieved I don't have to replace the alternator as it has been in the 20's here lately and I don't feel like working on the truck.
#5
Those grids must suck a tremendous amount of power to produce what looks to me like about a 4-5 volt drop from a running 120 amp alternator. It's hard to tell with that excellent, easy-to-read OEM gauge. I leave everythging including the headlights turned off for the first mile or so down the road. I can get away with that around here because there's literally no traffic on the road when I leave for work at 0500. Probably won't hurt much, but not a good idea to unnecessarily subject stuff like stereo equipment to that voltage fluctuation.
#7
Registered User
Here is something I posted a few days ago on anothersite that might help out here.
Here is the cycle time for the heaters from the Dodge manual.-
PREHEAT, BEFORE START CYCLE
Above 59 degrees F does not activate
18 degrees F to 59 degrees F Cycles for 10 seconds
1 degree F to 18 degree F Cycles for 15 seconds
-15 degres F to 0 degrees F Cycles for 17.5 seconds
below -15 degrees F Cycles for 20 seconds
POST HEAT, ENGINE RUNNING CYCLE?
Above 59 degrees F No
18 degrees F to 59 degrees F Yes
1 degree F to 18 degrees F Yes
-15 degrees F to 0 degrees F Yes
Below -15 degrees F Yes
I cannot find how long the post heat cycles are.
__________________
Here is the cycle time for the heaters from the Dodge manual.-
PREHEAT, BEFORE START CYCLE
Above 59 degrees F does not activate
18 degrees F to 59 degrees F Cycles for 10 seconds
1 degree F to 18 degree F Cycles for 15 seconds
-15 degres F to 0 degrees F Cycles for 17.5 seconds
below -15 degrees F Cycles for 20 seconds
POST HEAT, ENGINE RUNNING CYCLE?
Above 59 degrees F No
18 degrees F to 59 degrees F Yes
1 degree F to 18 degrees F Yes
-15 degrees F to 0 degrees F Yes
Below -15 degrees F Yes
I cannot find how long the post heat cycles are.
__________________
Trending Topics
Thread
Thread Starter
Forum
Replies
Last Post
5.9Excursion
3rd Gen High Performance and Accessories (5.9L Only)
1
03-13-2008 07:08 AM