Electric Element in Heater

[mohammad]

Attachment 13656
Relay box(tested all 3 elements with ammeter) working

How does one test the elements? do you just remove the relay and run an ammeter across the terminals?

[Fummins]

That should work.
To clarify previous posts. 14-15 have 3 fuses under the hood and 17 and up have 2.
They aren't different because they were delivered to a different town.

[mohammad]

I can tell when the heater kicks in. Its most noticeable when you're stopped and idling. If you turn the heat off, your idle will go to the normal ~800ish. If you turn the heater fan on, even to the first setting, it kicks the idle up to about 1200 rpm.

I have the manual heating controls, poverty edition. I feel like last winter id get heat a little faster and I would also have the higher idle. now a days I idle at approx 800rpm immediately after starting. Whats the easiest way to tell if the system is working? I was going to try and bypass the relay to measure current. But my amazon special multimeter is fused for 10 amp max. I guess the easiest thing would be to see if power goes to the relay solenoid when the car meets the set conditions.

Before i go on a time wasting adventure. is it universally agreed on the forum that the rpm's go up to approx 1200 when the PTC heater engages?


Fixed itself today. I now get the 1200 rpm high idle but it doesn’t seem to increase/decrease by turning heat on/off. Also for a 600w heater I would expect instant warm air. Takes me about a minute to get warm air.

[mohammad]

I would imagine so.

25A * 3 = 75A. That is a lot of amps.

75A * 13.1V = 982W

982 W = 1.3 hp

Alternators are around 50% efficient, so those heaters on full blast suck up around 2.6 horsepower. That is significant. Cruising at 50 mph probably only takes 10hp.

Isnt this an impossible amount of power to draw from an 85 amp alternator? how can one device draw 75 amps?

[Fummins]

The ptc heater looks pretty chunky. I just pulled one out of a heater box for the first time.

[Mark]

The ptc heater looks pretty chunky. I just pulled one out of a heater box for the first time.

That is more substantial than I would have guessed, too. Thanks for sharing!

[Fummins]

That is more substantial than I would have guessed, too. Thanks for sharing!

Yeah, I had no idea.
I don't know what year this one is from, I'm guessing a 2015. I found a similar Mirage heater listed on ebay from a 2019 that showed 600W instead of 850W.

[foama]

My 1.0L stripped-not-so-naked does not have the PTC heater. The PTC element can be tested with a simple multimeter/Ohm-meter for continuity. Since it is a PTC (Postive Temperature Coefficient) it has a low electrical resistance when cold, and a much higher when hot.

The electric current for any electrical heater has to come from somewhere. The alternator is driven by the engine, and that uses lots of fuel. The efficiency of an alternator is rather low, meaning you must put in a lot of power to get a smaller amount of electric power out. Any electric heater will have a definitely noticeable impact on mpg.

[7milesout]

Any electric heater will have a definitely noticeable impact on mpg.

Is there a quick reach location I can grab a connector and disconnect it? I'd rather have the mpg, it doesn't get THAT cold down here.

However, it was about 52°F last night and the wife and I stopped by a gas station. She wouldn't stand outside to pump her gas, and said she was FREEZING. Hey, great white Canadian guys ... 52°F is freeeeezing, the wife said so.

I don't let her pump her gas if it is just her and I, but we were returning a rental car after picking her Matrix up from being repaired. Had to fill up the rental car before returning it, and her Matrix was (as usual) running on fumes. So we filled them both up.

Lots of complaints on the Matrix repair, it was not great. But since it is 13 years old, and 130k+ miles, I'll just put up with it I guess. Nothing major. A few small things. I'll just address them myself, and not use that place again.

[Fummins]

Is there a quick reach location I can grab a connector and disconnect it? I'd rather have the mpg, it doesn't get THAT cold down here.

However, it was about 52°F last night and the wife and I stopped by a gas station. She wouldn't stand outside to pump her gas, and said she was FREEZING. Hey, great white Canadian guys ... 52°F is freeeeezing, the wife said so.

I don't let her pump her gas if it is just her and I, but we were returning a rental car after picking her Matrix up from being repaired. Had to fill up the rental car before returning it, and her Matrix was (as usual) running on fumes. So we filled them both up.

Lots of complaints on the Matrix repair, it was not great. But since it is 13 years old, and 130k+ miles, I'll just put up with it I guess. Nothing major. A few small things. I'll just address them myself, and not use that place again.

I don't recall how easy/hard it would be to reach the connectors for that heater. It's probably easier to remove the fuse(s) or relays.
There are 2-3 fuses and relays(depending on the year) under the hood ahead of the battery that control the ptc heater. I haven't tried removing them. I don't know when they do and don't work. I do know that I have seen my headlights dim when stopped and while driving similar to when the grid heater would kick in on a dodge diesel when it's cold and still not up to temp.

I don't know the conditions that have to be met in order for the ptc heater to work.

No comment on the 52F being cold.