Hello.

I have a problem with my heating system on my Fiat punto Elx.

Yesterday evening I accidently left my interior light on in my car for about an hour and a half. When i returned to my car I found that my heating system would not work, No cold air nor hot air would come through the vents. Also when i turned my lights on i noticed that backlights on the symbols on the heating controls no longer worked.

Could this be a fuse problem?

I'm not the most knowledgeable person when it comes to cars, so excuse me for my non technical terms.

Thank you in advance.

Troy.

Smiffyboi said:

Hello.

I have a problem with my heating system on my Fiat punto Elx.

Yesterday evening I accidently left my interior light on in my car for about an hour and a half. When i returned to my car I found that my heating system would not work, No cold air nor hot air would come through the vents. Also when i turned my lights on i noticed that backlights on the symbols on the heating controls no longer worked.

Could this be a fuse problem?

I'm not the most knowledgeable person when it comes to cars, so excuse me for my non technical terms.

Thank you in advance.

Troy.

Click to expand...

I might be wrong, and I'm sure someone on here will correct me if I am, but I am sure that the ECU restricts power to non essential electrical systems when the battery power is low.

You may need to charge/change your battery.

could be. best bet is to check the fuses to the bottom right of the steering wheel. just have a look see if any of the fuse filaments are broken and replace any that are. if that dont work then report back.

dori2o said:

I might be wrong, and I'm sure someone on here will correct me if I am, but I am sure that the ECU restricts power to non essential electrical systems when the battery power is low.

You may need to charge/change your battery.

Click to expand...

may not be the case if they can still turn on the lights, but to for clarification, does the car turn over and start ok?

dori2o said:

I might be wrong, and I'm sure someone on here will correct me if I am, but I am sure that the ECU restricts power to non essential electrical systems when the battery power is low.

You may need to charge/change your battery.

Click to expand...

Thank-You for your reply.

Is there any other electrical systems this could effect? As far as i could tell the only thing not working was the heater.

Troy

SamuraiDragon said:

may not be the case if they can still turn on the lights, but to for clarification, does the car turn over and start ok?

Click to expand...

The Car starts fine yes.

I will go check fuses etc now...will report back in 5 mins.

Troy

SamuraiDragon said:

could be. best bet is to check the fuses to the bottom right of the steering wheel. just have a look see if any of the fuse filaments are broken and replace any that are. if that dont work then report back.

Click to expand...

Fuse filaments look fine, as far as damage goes. To be honest when i open that up, I have no idea what is what. but yes as far as any damage goes it looks fine.

Troy

may seem like a silly question, but was the heater working before and are the vents open? i cant see having the light on for an hour and a half will do anything else to the heater. does the light still turn on? have u tried different settings on the heater?

SamuraiDragon said:

may seem like a silly question, but was the heater working before and are the vents open? i cant see having the light on for an hour and a half will do anything else to the heater. does the light still turn on? have u tried different settings on the heater?

Click to expand...

Heater was working fine before, Vents are open, The light still turns on yes, and i have tried every setting on the heater.

Troy

could just be the heater unit packing in. nothing else done recently to disturb anything? changing parts etc anywhere in the car? just to rule out fuses/relays, check under the hood for any blown fuses in the engine bay fuse box as well. short of that im unsure. maybe someone else has ideas.

I dont know where the heater motor fuse is, so pull every fuse look at its filament and replace until you find one that's blown. Replace that and see if the heater motor works. Fuse box is to the door side of steering column and another under bonnet near the battery.

Look at the fuse filament if its clean its ok Just like a light bulb, if its blown you will see the spattered metal and no filament.

It might be the heater resistor has failed or the heater motor has failed. If the OP is not familiar with cars an auto electrician will be able to fix it. The mobile guys are very reasonable.

WhiteSei said:

I dont know where the heater motor fuse is, so pull every fuse look at its filament and replace until you find one that's blown. Replace that and see if the heater motor works. Fuse box is to the door side of steering column and another under bonnet near the battery.

Look at the fuse filament if its clean its ok Just like a light bulb, if its blown you will see the spattered metal and no filament.

It might be the heater resistor has failed or the heater motor has failed. If the OP is not familiar with cars an auto electrician will be able to fix it. The mobile guys are very reasonable.

Click to expand...

sorry for delayed response. I checked all fuses and they are all fine. I have had no changes to my car its just stopped out of the blue.

I also measured the voltage on the battery. which came out at 12.76. does that sound correct?

Troy

should be around 14v whilst the engine is running. iirc, if it goes lower than 9v when starting the engine, thats a sign battery needs attention. if u can borrow a spare battery and see if it gets u anywhere.

Weak battery causes all sorts of issues but wont prevent heater motor from turning.

SamuraiDragon said:

should be around 14v whilst the engine is running. iirc, if it goes lower than 9v when starting the engine, thats a sign battery needs attention. if u can borrow a spare battery and see if it gets u anywhere.

Click to expand...

My colleague got the 12v reading when the engine was off.. Unfortuantly i don't have a spare battery.

Troy

It wont be the battery. You'll have to get under the dash and find the heater fan resistor. Most likely the culprit. There's a recent post with pictures on this subject.

WhiteSei said:

It wont be the battery. You'll have to get under the dash and find the heater fan resistor. Most likely the culprit. There's a recent post with pictures on this subject.

Click to expand...

Oh right ok, any chance you could forward me a link for that post? I can't seem to find it. Perhaps im going blind.

I Appreciate your help.

Troy

You will have to do a visual search though the last 2 weeks of posts. IIRC it was labelled as a heater or fan problem.

Fuses to check are F8 (30 amp) and F31 (7.5 amp). Check that relay R8 is clicking in when ignition is on (if you put ign on and then pull relay out you should hear it click and then click again when you reinsert it).

A common problem with the heater circuit is a poor earth connection. There's a three way connector attached to the motor unit, under the glove box. There's a thick black wire that's the earth, another thick wire and a thin one. Pull the connector apart and look to see whether it's been burning and/or melting. If you can't get it apart it may be melted together. Search for posts about this and you'll find pictures of what to look for.

red