Dimming dashboard and dome lights - what could be the reason?

**AcidBurn** · January 27th, 2014 06:51 PM

Mga sir, ano po ba normally ang culprit pag ini-start mo yung auto ay nagdi-dim ang mga dash and dome lights? My enduro battery was just bought last July and my alternator was overhauled at pinalitan ng rectifier diode and ic regulator last Aug. Ang sabi nung gumawa ng alternator ko ay normal lang daw yun kahit na very obvious yung pag-dim ng mga lights?!? I dont think this is normal kasi yung isang auto namin pag ini-start ay steady lang ang mga ilaw. TIA

**12vdc** · January 27th, 2014 07:08 PM

Most of the times, dimming is normal. Starter motor plus starter solenoid eats a lot of your battery current making voltage drop.

I'd check the CCA of the battery, baka lower capacity yung napalit mo. You may want to check also the groundings, battery terminals, starter connections for loose/ corroded/ poor contacts. For me, as long as the vehicle starts in one click, that should not be a problem.

**AcidBurn** · January 27th, 2014 07:17 PM

Originally Posted by 12vdc

Most of the times, dimming is normal. Starter motor plus starter solenoid eats a lot of your battery current making voltage drop.

I'd check the CCA of the battery, baka lower capacity yung napalit mo. You may want to check also the groundings, battery terminals, starter connections for loose/ corroded/ poor contacts. For me, as long as the vehicle starts in one click, that should not be a problem.

Sir, yun nga po ang problema...hinde one click especially in morning, most of the time hard starting. By the way sir, starter is also new, bought a reduction starter just last month.

**Retz** · January 27th, 2014 07:28 PM

Originally Posted by AcidBurn

Mga sir, ano po ba normally ang culprit pag ini-start mo yung auto ay nagdi-dim ang mga dash and dome lights? My enduro battery was just bought last July and my alternator was overhauled at pinalitan ng rectifier diode and ic regulator last Aug. Ang sabi nung gumawa ng alternator ko ay normal lang daw yun kahit na very obvious yung pag-dim ng mga lights?!? I dont think this is normal kasi yung isang auto namin pag ini-start ay steady lang ang mga ilaw. TIA

Sign yan sir ng poor battery kaya nag dim ung dashboard light mo pag ni start mo. Have it check na lang baka defective na kahit wala pa 1 year or pwede rin ung alternator mo sir kasi sabi mo nag overhaul ka.

**12vdc** · January 27th, 2014 07:32 PM

Diesel or gas Engine? Being a good mechanic is like a phsician, you should know the background and history of the patient..

Before you replaced alternator, batteries, and starter what were the symptoms? Your mechanic did the elimination method hence all the items were replaced? I bet yours is the typical "poorly charging battery" due to bad alternator, not performing exciter diode/ regulator or poor grounding. I'd suggest hook a Voltmeter, start the motor, then see if its within 13.8V charging voltage.

**lowslowbenz** · January 27th, 2014 08:23 PM

Originally Posted by AcidBurn

... culprit pag ini-start mo yung auto ay nagdi-dim ang mga dash and dome lights?

My take.

Normal. Your starter is requiring a large volume of current from the battery during starting, especially on a cold engine. I suggest you turn off all lights before you start your car.

**miko101130** · January 27th, 2014 08:36 PM

kung diesel sasakyan mo TS at nag crank ka nang engine, sure yan, dim ang dashboard mo... pero once started eh wala nang dimming

kung gas engine ka at crank mo, the dimming would be very minimal...
diesel is much harder to start thus requires a lot more power from batteries as against sa gas engines.
your starter will pull amps in excess of 150 amps

what is not normal is kung nag dim ang dash mo kahit nag idle ka lang...
or if your dash dims on idles and then brightens when revved high...

assuming na sabi mo eh nag hahard start ka sa umaga, im also going to assume na diesel engine ka...
madami causes ng hard starting, glow plugs/ starter solenoid malfunction/etc etc....

if gusto mu mawala sa equation ang battery mo as a problem, ipa "load test mo" and have a specific gravity read out... ( usually can be done sa mga battery dealers.)

**lowslowbenz** · January 27th, 2014 08:43 PM

Originally Posted by miko101130

what is not normal is kung nag dim ang dash mo kahit nag idle ka lang...
or if your dash dims on idles and then brightens when revved high...

+1

This is not normal.

**AcidBurn** · January 27th, 2014 08:46 PM

Originally Posted by miko101130

kung diesel sasakyan mo TS at nag crank ka nang engine, sure yan, dim ang dashboard mo... pero once started eh wala nang dimming

kung gas engine ka at crank mo, the dimming would be very minimal...
diesel is much harder to start thus requires a lot more power from batteries as against sa gas engines.
your starter will pull amps in excess of 150 amps

what is not normal is kung nag dim ang dash mo kahit nag idle ka lang...
or if your dash dims on idles and then brightens when revved high...

assuming na sabi mo eh nag hahard start ka sa umaga, im also going to assume na diesel engine ka...
madami causes ng hard starting, glow plugs/ starter solenoid malfunction/etc etc....

if gusto mu mawala sa equation ang battery mo as a problem, ipa "load test mo" and have a specific gravity read out... ( usually can be done sa mga battery dealers.)

Sir, gasoline po..honda ang auto. Ang pag-dim po ay pag ini-start lang yung engine, pero once na umistart na (after several tries) ay back to normal ang mga lights. Normal lang po ba ito or there could be something's wrong with the car? Thanks

**lowslowbenz** · January 27th, 2014 08:56 PM

^

Normal.

Your hard starting issues maybe mechnical in nature. Maybe.

Again, do not turn on your lights BEFORE starting your engine. Imbes na mapunta halos lahat na kuryente ng battery sa starter, nakikihati pa yung mga ilaw mo. Kaya naman siguro hirap umistart ang kotse mo.