AC12G testing

[runaway!]

Got a set of 8 plus one of the AC12G glow plugs for the 5.7 GM diesels, tested them for quality.

Test Details

Ran each one on a charger set to 6 volts/6 amps for 10 minutes each, attempting to cook off any moisture that may cause swelling.

Then ran the survivors at 12V/6 Amps for a minimum of 45 seconds.

Results:

Each one that failed, did so on the 6 volt setting inside of 25 seconds. They cooked off with a .22 cal type bang and continued to operate.

The ones that passed the 6 volt setting also survived the 12V testing. Tested one of them out to 90 seconds with no failure.

I will be running one at 12V/6 amps to failure, will update when results are in.

It appears that if testing the units prior, the survivors will take a huge amount of abuse. The dead ones can be returned for replacement and retesting.

EDIT: Just checked the one for testing to failure, 10 minutes at 4.5 amps of draw (same at the start of the test) and no swelling or cooking off.

In total, 4 of the pack of 8 survived. The 9th failed immediately, so a survivor was used for failure testing.

2 or 3 trips to return the bad ones should result in a set of AC12G that will melt the wiring harness before they fail.

 

[jperecko]

That is pretty cool but I always thought that a charger would not put out enough amps to actually drive them to failure... Maybe still try testing them with a connection to a healthy battery and see if they still last.. If they are failing at 6 amps, they might not at full draw. (or is 6 amps full draw?)

 

[FordGuy100]

I'm more interested in the 12v setting, as thats what our trucks apply to the glow plug relay.

And do we know how much each glow plug draws in amps?

Sounds good though, how fast did they heat up, being 12v glow plugs?

And since these are 12volt plugs....will it work like a starter in that when the voltage drops, they draw a ton more amps (which would cause them to fail at 6volts)?

 

[runaway!]

Well, it is a 6 amp charger - and they never pulled more than 4.5 amps. But I'm no electrical expert.

Almost the entire tip was bright red during the test, so much that it started to melt the rubber on the charger's gator clips.

 

[runaway!]

I'm more interested in the 12v setting, as thats what our trucks apply to the glow plug relay.

And do we know how much each glow plug draws in amps?

Sounds good though, how fast did they heat up, being 12v glow plugs?

And since these are 12volt plugs....will it work like a starter in that when the voltage drops, they draw a ton more amps (which would cause them to fail at 6volts)?

The very tips started to glow inside 10 seconds, they were lit up like an x-mas tree inside 30 - then remained there even after some cooked off.

I'm seeing if I can get some manufacturer data on the intended draw. I observed a 54 watt draw at 12V/4.5A settings. So running all 8 is a 432 watt draw on the system. That's almost twice what a Cummins intake heater will draw.

I did the 6v setting to try to drive out moisture prior to the real test, doesn't appear to matter however.

 

[runaway!]

Just read they are to draw 70 watts each per manufacturer, however my charger may not be totally accurate. Plus I heard glow plugs rarely perform to the anticipated current draw. I think they build a level of safety into them, ironic considering the moisture will make them not just swell - but pop off like a firecracker.

EDIT: I took a closer look at current draws (I didn't pay a huge amount of attention during testing due to being concerned with being near a GP that decided to suicide)

Glows red inside of 5 seconds, current draw on ampmeter spiked and a 6 amp draw is 72 watts, pretty close to OEM specs on the 12G.

Full glow obtained inside 30 seconds, current draw tapered off between 4.5 and 5 amps. I imagine this will vary a little between plugs.

 

[FordGuy100]

So they are rated for taking roughly 6 amps a piece. I like the idea of hooking one up to the battery, to see what it does.

But...it does sound like they will perform good

 

[runaway!]

Checked the tolerance of the elements after heating

New is 4.8mm post burning had maximum tip size of at 4.94mm width once cool, was visibly larger during heating - but I would expect that consider the temps reached.

I can check one on a new battery, but I will have to rig something to measure the current...

Will be back with results in a little while...

 

[FordGuy100]

By the way...thank you for taking the time to run these experiments, we appreciate them

 

[runaway!]

No problem, I've enjoyed hacking into stuff like this. If it doesn't break my budget or get beyond my ability, I'll do it no problem.

Hooked one up to a brand new (literally new, 1 week old) battery on a full charge - Pulled a max of 7 amps then dropped down to 5-6ish and remained there.

I've heard these are self limiting GPs, so I imagine that is why the current drops as the temps rise.

 

[runaway!]

Anyone know who carries the Wellman 12s for the GM 5.7? If the quality is what everyone says they are, the price is comparable and a better option than returning the asploded ones...

I just can't find anyone who carries the 12s!

 

[Black dawg]

those amperage numbers sound real low, its been awhile since I put an amp clamp on an older style plug but it seems like they should be drawing about 15 amps at 12v

 

[runaway!]

180 Watts per plug? I don't mean to be rude but I seriously question that, 1440 watts on the whole system? I have space heaters in my garage that don't draw that much current but will heat a 150sq foot room in Wisconsin weather.

But then again, I'm no electrical expert either...

Hmmm... if you are talking the OEM style plugs from the 6.9 then yes, it is possible... Those are 6V plugs, which is 90 watts per plug or 720 watts / 60 amps on the whole system. Not sure what they actually get from the controller in terms of voltage though.

 

[david85]

I tested ONE wellman 088 (supposed dual coil) and it swelled up like an union in about 20 seconds. Swelling started right around the 9 second mark, but I tested on a large starter battery, not a charger.

Tried the wellman 080s too, the drop in replacement for the stock plugs in my truck. Well, lets just say they helped me rebuild my engine................

I read all the press releases about WAP glow plugs being all american and having great contracts in the US military, but take if from me, its F$$(_(& BULLS***!!!!!!

I will say to all of you out there who are thinking of replacing BERU plugs with something else....
TEST FIRST, before installing them. FAIL at least one to see how they fail. If the tip swells and breaks off, you are screwed. If the tip ruptures in small pinholes, then the plugs are still retrievable.

Heard good things about true dual coil plugs made by autolite, bosch and AC delco, but have been unable to locate them locally for testing.

 

[NCheek]

I have pics in my webshots of what a stock 1986 6.9 controller will do to the wellman plugs. Let's just say for the umpteenth time: Beru glow plugs are "CHEAP" INSURANCE!
















*If you want cheap though, don't buy them from O'reilly's, plan ahead and buy online to avoid $18 a plug because you need them now...