Help me diagnose a car/house electrical problem

Factual Questions
1

Or, “Why was Piper wandering in his driveway with a miniature Christmas tree on Christmas night, at - 28 C?”

Our Honda CRV has been having trouble starting recently in the cold snap we’ve been experiencing. I’ve called CAA a couple of times for a boost, and they’ve suggested that it may not be the battery at fault, because it starts easily once boosted, and the battery isn’t even 3 years old. Suggestion from the most recent one was to put a trickle charger on over-night, before our roadtrip to relatives on Boxing Day tomorrow, and see if a long highway run charges it up.

Now, I’m not a car guy, but I’ve heard that before - that in cold weather, short drives around town aren’t enough to re-charge a battery, and a good highway trip is needed. Since the CAA guy was giving that advice against his financial interest (I would have bought a new battery there and then from him if he had suggested it was needed), that suggests to me that his advice is good. But why isn’t a drive around town enough?

But, you want to know about the miniature Christmas tree.

I went out tonight, after the Christmas feast, after seeing Piper Dad home to the senior centre and Piper Cub finally crashing after all the emotions of Christmas! presents! Grandad! Christmas tree!

I plugged in the block heater and put the trickle charger on. The charger has two indicator lights - one to indicate that there’s a circuit, and one to indicate power. The circuit light came on, so I’m confident I hooked the charger up properly (red clamp to positive post on the battery, then black clamp on the metal strap holding the battery in place).

But, the power indicator didn’t come on. Bugger! (And I’m getting cold. Did I mention that I’ve lost one glove, one mitt, and one pair of mitts over the past week, so I’m using a hybrid of a glove on the left hand, and a mitt on my right, and the mitt isn’t dextrous enough to do clamps and fidgety things, and damn, -28 C is cold, even with no wind.)

So, I go to the power outlet; it’s got a ground reset button, so I push it, then re-check the charger; still no power indication. I move the cord to another outlet; no power indicator. I go downstairs and check the breaker box; they’re all good.

How do I test the outlets? A-ha! The PiperCub has a little white Christmas tree, all of 18 inches tall, with lights! I unplug it, and take it outside. I plug it into the outlet. No lights. I unplug the cord going to the Honda, push the reset button on the outlet, and then plug in the Christmas tree.

Excelsior! the little Christmas tree lights up! So, it’s not the house wiring and the outlet that’s the problem; there’s power to the outlet.

Then I plug in the cord again and pop! out goes the Christmas tree. I unplug the cord, hit the rest button, and the tree lights up. I go to the Honda, unplug the trickle charger, leaving the block heater plugged into the cord, then go back and plug the cord in again. Out goes the Christmas tree lights.

A-ha again! is it the block heater, then? I unplug the block heater from the cord, plug in the trickle charger on the cord, then go back to the outlet and hit the reset button. The Christmas tree lights up! I go back to the Honda and check the trickle charger - and both the power indicator and the circuit indicator are lit up.

So, my conclusion is that there’s something wrong with the block heater - it’s drawing too much power or something, tripping the breaker in the outlet box.

What say you, O Doper car and electrical guys?

2

If the block heater was drawing too much current, you’d blow a fuse. I wonder if it has a very small short (like it’s starting to rust out) and the GFI is noticing the current leak.
Also, is that the only outlet on the breaker? If not, make sure the others aren’t also GFCI. I’ve found that when you wire a GFCI into another GFCI (which is generally incorrect) they have a habit of popping each other.

ETA, ‘short’ may be the wrong word. I mean short to the engine block.

3

good troubleshooting. the tree is a colorful and rewarding voltage tester.

where the cord of the heater goes into the plug especially or maybe into the heater could break and cause the breaker to trip. the block heaters take lots of hard use and do break.

seems you should sew a cord to your mitts and gloves and feed it through your sleeves.

4

I had to read that twice to figure out the the second instance of the word ‘cord’ had nothing to do with an electrical cord.

5

In brief, starting the car requires a lot of energy for a short time while charging the battery requires relatively little energy over a long time. Part of that is that the lifespan of batteries depends to some extent on how rapidly they’re charged. But you also don’t want to be driving around with the weight of a giant alternator in there because it is bad for mileage and isn’t really needed.

Driving around town is done for shorter periods at varying engine RPM, neither of which is particularly useful for charging batteries.

Having said that, if the battery can start the car fine one day and then you park the car for a couple days and it won’t crank the engine, you either have a bad battery or something draining power while the car is sitting. And the second will cause the first if it goes on long enough.

GFCI receptacles work by comparing tiny differences in the current passing through the hot and neutral wires of the outlet. If not identical, it assumes that there’s leakage to ground somewhere and trips.

While this isn’t exactly rocket science (there are packaged circuits to do this which the manufacturers use), there’s a reason that cheap GFCI receptacles are under $10 at the home center while a good brand (QO, etc.) GFCI circuit breaker is over $65 just down the aisle. Aside from making fewer of the breakers, they’re also much better quality because people do not want to traipse down to the basement every couple of days to reset the thing.

Unfortunately, outdoor GFCI receptacles tend to be even more “nervous” than the rest - they’re in uncontrolled temperature / humidity areas and it is quite common to use long extension cords with them.

6

Yes - my voltage tester lit up like a Christmas tree!

7

Does idling the engine do as much to charge the battery as driving down the freeway? What about driving at say 25 MPH? I always assumed higher RPM would charge the battery faster, but it’s probably not that simple.

8

Slight jijack: I have also been having problems with my Honda (Civic) block heater since we changed the outdoors power receptacle to a GFCI. The outlet trips immediately when I plug in the block heater. I went to the Honda dealer, they said the block heater works fine.

My car parking is about 35 feet from the outlet, so I have a pretty long cord. But last summer I used that same cord, with another cord at the end of it, to power a demolition saw at the other end of the yard (maybe 150 feet away), and it didn’t trip the GFCI outlet in question. I also tried a circular saw, etc.; only the block heater trips it.

So I will be interested in whatever solution Northern Piper finds. (Would it help if I purchased a tiny Christmas tree?)

9

The block heater is just a short loop of a resistive heating coil (like the burners on an electric range) which replaces one of the engine block’s core plugs. If the case/sheath is compromised, it can cause coolant to seep in and act as a current leak, tripping the GFCI. Replacement heaters aren’t expensive, but usually require a partial or full coolant drain/fill.

10

I agree with everything Terry posted and second having a quality GFCI breaker in use with a engine heater.
And, the cord to your heater is very susceptible to degrading. Before replacing a block/engine heater consider replacing the cord witch are available from most auto parts stores. And while at it, purchase a good cold weather extension cord with a lighted end. I believe just pluging into a cheap cord will cause sparking and can be the cause of GFCI trips. And a synthetic engin oil helps also.

11

Really? How so?

12

This is good advice.

Sounds like you have a little “leakage " current.” Only block heaters I have used have been on stationary engines, so not sure of the cords used. Assume the heater has a short pigtail with a plug that is plugged into an extension cord to the wall.

The problem can any one of the componets. Cord, heater, plugs. or at the GFIC outlet. I would start by unplugging the lheater from the cord and just plugging the cord in. And go from there.

As to the battery. When an engine is running at an idle the voltage from the regulator may be a little below full voltage. At higher RPMs the regulator will control the voltage to maintian the voltage at or just below full voltage. And the battery will have a slow charge. In cold weather a battery will not preform as well as warm weather. And on first start the engine will be colder even with a block heater. So a restart after running for a time is easier.

13

Try cleaning and drying the plug of the pigtail attached to the heater. There may be enough road salt accumulated on it to cause a short to the ground wire.

14

Could just be nuisance tripping because of the heating coil in the block heater.

15

Check this video out it will save me a lot of finger picking. :o
Viscosity in winter(cold winter).
I took a Fluid, Lubrication Technicians training course through “Fluid Life” and worked in Hard Rock Mining for over 34 years. I am interviewed on this History Channel series,
Extreme Engineerin;

and made it into the October 2002 National Geographic Magazine(picture) I am the one wearing the hat.

16

Can’t you just tell us what synthetic motor oil has to do with the GFCI tripping?

17

Well the OP is struggling with getting his car running in cold weather. His battery is being taxed because of this.

I added the synthetic oil suggestion as this would help overall with his starting issues by not over taxing his storage battery.
I drive a 1999 Dodge 4X4 with 300K and it isn’t cold enough yet to plug in at night because i use full synthetic engine oil, and i for the past 33+ years respond for emergency calls at all hours and when the engine starts its in gear and rolling.
I would not be able to do that without synthetics!
It was -10F the last couple nights and my cord will have to come out soon. :wink:
And i will turn my ignition on short pause off and back on, pause before cranking as this gives a little richer prime, IMHO and i get a faster start because of this.

18

given the first link in your previous post, I sure hope you’re not just here to shill for Amsoil.

19

Well, even with the trickle charger on all night, it didn’t start again this morning, so called CAA for the third time in three days and they put in a new battery. I’ll take it in to Honda asap to have the block heater fixed.

Thanks for the comments, all. On reflection, my extension cord is pretty old, so it may be contributing to the problem - will get a new one as well.

20

No I do not,
I do sell oil as a part time worker at an Auto Parts Store and we don’t stock Amsoil, the video just worked for the explanation i wanted to post.