electrical gremlin glowplug/headlight/tach

[strada-caster]

This only happens on start up.

I turn the key to the on position to heat the glowplugs. If I decide to turn the headlights on during this initial heating cycle, I will get a buzzing sound, and my tachometer will jump to 750rpm(engine not on).

any ideas?

[Strada 92]

Your alternator is gone.
Go in a good electrical shop for a rebuild of your unit.
RPM is controlled by alternator.After the glow plug first shot,you start and the alternator give the signal for the afterglow shot.
You have a 50AMP. unit.Tell the shop to build you a 65AMP. just like they do for me.

[strada-caster]

sounds wierd...but more likely than 3 crossed wires. i'll have to give the alternator a bench test...
just one more thing to learn

[tonydca]

If the engine is not running, you're not (yet) using your alternator - sounds to me like your battery is not holding a charge.

If the 12V on your vehicle feeding the electronics gets too low (dying battery, glow plugs on, headlights on...) lots of weird stuff can happen.

Check your battery (and alternator too, can't hurt), fix 'er up, and I betcha this issue will vanish.

[strada-caster]

hmmm, I've checked the battery just recently and it was good, not too old either <3 years.

but, I have been playing with a light bar and 5 100w lights. I was connecting them straight to the battery (not for very long) just to see if they were all working. maybe this took enough juice from the battery, and then the next morning I started the truck and had this symptom. I can't recall my exact schedule, but this may be a possibility.

[thedjjack]

This only happens on start up.

I turn the key to the on position to heat the glowplugs. If I decide to turn the headlights on during this initial heating cycle, I will get a buzzing sound, and my tachometer will jump to 750rpm(engine not on).

any ideas?

"any ideas"

Don't put your headlights on when your starting. seems simple?

[strada-caster]

"any ideas"

Don't put your headlights on when your starting. seems simple?

thanks captain obvious, but I was just wondering if there is an underlying problem.

[strada-caster]

This only happens on start up.

I turn the key to the on position to heat the glowplugs. If I decide to turn the headlights on during this initial heating cycle, I will get a buzzing sound, and my tachometer will jump to 750rpm(engine not on).

any ideas?

so this problem sorta went away and I forgot about it. now it's back with a passion, but symptoms have changed.

I now know the buzzing noise is coming from the aftermarket 'low beam DRL module' installed. No, replacing it did not solve the problem.

The daytime running lights and high beams work perfectly fine other than the buzzing noise.

it buzzes when:
key is in acc, and i turn the headlights to on. car is off

it buzzes and the tach goes to 750 when:
key is in on position, and i turn the headlights on. car is off

when the car is on, everything works normally except when i turn the headlights on it buzzes. buzzing goes away if i flick to high beams.

if i remove the DRL module from the circuit, I have no lights at all.

[tonydca]

This only happens on start up.

I turn the key to the on position to heat the glowplugs. If I decide to turn the headlights on during this initial heating cycle, I will get a buzzing sound, and my tachometer will jump to 750rpm(engine not on).

any ideas?

so this problem sorta went away and I forgot about it. now it's back with a passion, but symptoms have changed.

I now know the buzzing noise is coming from the aftermarket 'low beam DRL module' installed. No, replacing it did not solve the problem.

The daytime running lights and high beams work perfectly fine other than the buzzing noise.

it buzzes when:
key is in acc, and i turn the headlights to on. car is off

it buzzes and the tach goes to 750 when:
key is in on position, and i turn the headlights on. car is off

when the car is on, everything works normally except when i turn the headlights on it buzzes. buzzing goes away if i flick to high beams.

if i remove the DRL module from the circuit, I have no lights at all.

If one of your light/accessory circuits has a little mechanical relay somewhere in the circuit (common thing), then this relay needs 12V or thereabouts to it to activate.

If your system voltage is low (from a poor battery charge) then turning on too much load on the circuit will drop the voltage low enough for the relay to click off.

With the relay off, whatever the relay was powering switched off, the load on the system drops, the voltage in the circuit now jumps up, enough to turn the relay back on,

But with the relay on, the load on the system goes up, voltage drops, and the relay kicks out..

And so on, and so on and so on, really quickly. Aka **Buzzzzzzz**

Check the voltage from your battery with the engine not running, then running. Recently-replaced battery or not, if it won't hold a charge, this kind of thing can happen.

FWIW, if said battery has been fully discharged in the recent past and left for any period of time, doing so is hard on the internals and chemistry of a lead-acid battery and can damage it. This is why some batteries are "deep-cycle" and some aren't.; the former are made to take such abuse.

[strada-caster]

makes sense..I'll take a look at the battery, see how that is holding up. and never did check out my alternator. maybe that is where my problem lies.

[92Nicopolis]

I would check bolth batts. its not uncommon to have a dead plate in one of them, i had a prob like this with my old 6.5 chev, the shop told me it was all in my head but i pulled the batts and checked and one was 1.2volts low but still good amps chanced that batt and all was good again

[strada-caster]

DRL unit on my truck is 44040 (grote). sent a question to the manufacturer and they said they are aware of the buzzing but only upon first install, not after a period of time like my situation.

[strada-caster]

Took the following readings today.

Battery
Truck off 12.34
Truck on 13.6

the module has 3 wires piggy-backed into the harness in the steering column.
yellow pink blue
key @ acc, lights off 10.61 10.81 .13
key @ on lights off 9.43 9.7 .12 makes sense, draw from glow plugs
key @ on lights on 5.6 10.9 5.3

truck on, lights off 11.87 12.17 .14
truck on, lights on 6.4 12.16 6.02
truck on, high beams 11.66 12.1 .32

[strada-caster]

Since the pink and yellow wire have voltage at all times. would I be able to just cross those 2 wires??? would that blow up fuses? cause more problems?

[strada-caster]

I ended up crossing those 2 wires....gives me high beams at all times no matter what setting i'm in. all the lights (tail signal interior) work as though they should until I flick the switch to highbeams, then the taillights turn off (wierd).

Does anybody know where my headlight relay (if there is one) found?? I found the signal relay and hazard relay just to the right of the pedals...argggg

don't forget I'm a strada, not a delica.