low voltage at start up - Is this Normal

[REdmon]

This has been going on for about a year in which the voltage reading at start up remains at 10V for about 30 seconds and then the voltage climbs up to 14.5V. I understand the grid voltage heaters turn on (drawing lots of amps and that is normal. However, in the past I don't recall the voltage dropping to a level where thee check engine light remained on. Since this is a 1999 Dodge 2500, does that sound like proper operation for the age of the truck (170K miles.)?

Thanks for any information you can share or if I should be looking at anything beside cleaning both battery connections, voltage drop test on cables to terminals, as well as the alternator and fuses,

Thank you for any help you can provide in this issue.

Ron

 

[JR]

Is it the check engine light or a check gauge light? How long does it stay on for? What is the ambient temperature when this is happening?
Either way, you may want to have your batteries load tested. Make sure they are disconnected from each other, if you dont have a load tester and take it to a parts house most are not aware you have to test the batteries individually.
It sounds like your alternator is doing its thing if voltage comes up to 14+ volts.

 

[REdmon]

Hmmmm, I am gonna have to go back out tomorrow and confirm which one. I did load test the batteries, but they were hooked together and the test came back "Fail" using a 100 amp load tester. Voltage on the batteries were 12.10V. The temperature was 60F. These were Intrastate batteries that were new in July 2015. I will separate the batteries and rerun the load test and report results.

Thanks JR. Ron

 

[BigPapa]

It’s your “Check GAUGES” light. Mine has done the same thing since I built the truck, I just figured it was from the conversion. The light doesn’t stay on in the warmer weather because the grid heaters don’t come on.

-Scott

 

[JR]

Hmmmm, I am gonna have to go back out tomorrow and confirm which one. I did load test the batteries, but they were hooked together and the test came back "Fail" using a 100 amp load tester. Voltage on the batteries were 12.10V. The temperature was 60F. These were Intrastate batteries that were new in July 2015. I will separate the batteries and rerun the load test and report results.

Thanks JR. Ron

Weak batteries will definitely contribute to the problem as they don't have enough reserve. I used to run Interstate batteries in everything I had but their quality has really dwindled from my experiences.

Scott I swear I remember Dodge releasing a tsb years ago to lower the set point for when the check gauge light came on. I looked and can't find it now.

 

[GAmes]

Operation of the grid heaters is covered in the factory service manual. The colder the wx, the longer the heaters stay activated. The initial low voltage until the grid heaters turn off sounds normal to me.

 

[JR]

At 60* the grid heaters shouldn't be enough of a factor to make a difference.

 

[BigPapa]

I just figured my situation was from putting the '95 12V in the '98.5 24V truck. I used all the 24V wiring and components on the 12V engine, ECM and all senors including the APPS, basically fooling the truck into thinking it has a 24V in it. This is the only "issue" I can't get rid of.

-Scott

 

[REdmon]

Thank you to everyone who replied. Although I had removed and cleaned the terminals of the batteries yesterday, I did neglect to pop the cell covers off and inspect. No excuse, I just have neglected inspecting the batteries (shameful I know). The cell fluid levels were all low. I topped them all off with distilled water and got the charger going. After 5 hours, I disconnected the charger (voltage checks 13.65V during charging and 12.65 after removing charger and rest period).

Disconnected the batteries and then ran load tests. 100 amp draw for 10 seconds on each separated battery came back with voltage readings in the green. Hooked the batteries back into the truck and turned the key to on. All console lights lit up normal and turned the key to start.

The truck fired up instantly and the "Check gauges" light was on for only 2 seconds. The grid heaters came on with without an issue for the batteries and the voltage gauge proceeded to rise from ~11-12V on up to 13.5V. Truck is operating as it did a year ago.

I was lucky my neglect of the batteries didn't require replacing them. Good lesson for me to regularly make my battery checks. The use of AGM batteries in my other vehicles made me forgetful, but I won't let this happen again.

Thanks guys, your input got me back on track.

Ron

 

[Joe Mc]

I've had great experience with the EverStart MAXX Batteries WallyMart sells. Brief bought my truck in 05/01 had original batteries that lasted till 06!!! Got the MAXX-27 (810 CCA) 3 year free replacement 2 year prorated. 11/12 had them tested both had full charge on read fail the other good - not bad 6 years. Replaced with same. 11/18 same deal one fail the other good and another 6 years. Replaced with same - so I should be good till 2024. Recent cost was $119 ea. I think the first set cost around $52 ea.