RicardoM

OK. So far we have established that a new factory A/C unit exists on Felicia GLX after 1998. As this is not documented anywhere, I guess that only a Czech / Slovak citizen can shed some light. @Papez ? In this Czech forum topic they talk about two types of A/C but sadly with no photos and with no usable info.

I am not familiar with that kind of A/C housing unit. No documentation that I have shows that is a Felicia factory setup for A/C. Are you the first owner of the car? On the other hand, only one cabin filter was fitted on Felicia. The carbon foam type (like on a gas cooker hood) OR the plastic one with gills. Two cabin filters are only on Felicia with carburetor. They are a combination of Favorit and Felicia.

Does your car has air conditioning? If yes, the A/C fan/blower is identical with the one in his car? Show us a photo of the engine bay of your car. I really insist on that. Because the original A/C unit for Felicia doesn't look like that.

It is just a matter of removing 9 or 16 metallic clips. Be very careful. They have the bad habit of flying and disappear.

The manufacturer clearly specifies the specific type/model of car for their filters. Furthermore, they have an installation manual for each filter. You can't put it wrong if you know what you're doing. K1048 is only for Skoda Favorit and Skoda Felicia on carburetor. K1100 is for the rest of Skoda Felicia.

@IneedAManual From all your answers, my intuition tells me it is better to let your old pop repair the car. As for the user manual, if you read my previous reply (or maybe decided to ignore it?) it is useless in terms of repairing the car. The Serviceplan too.

Haynes manual is about what they THINK they understood from the Skoda Felicia FACTORY manual.

The only problem with the air intake filter for the ventilation and heating system is to use the correct filter for the right car OR to understand how to fit it. Wait a minute, you are not the one that complained about not being able to fit the filter. What has the filter in the first post anything to do with you?

There are people that looked for that manual in English for a couple of years. Some had to sell a kidney to get it Now joking aside, the most fortunate of us have the manual only in paper format. The bad news is that you don't have the description of fuses in Felicia Owner's manual. The manual is more useful for somebody who needs to know the basics of OPERATING and MAINTAINING the car. It's not a repair manual. I gather you are Swedish. How old are you? What issues has your car?

I was with you up to the point you said "...and may be able to induce a voltage spike across the antenna." In order to produce a meaningful effect (a current), the voltage induced in the "receiving wire" has to be part of a closed circuit. The antenna is an open circuit. No current flows through the antenna wire. Moreover, the antenna is followed by a circuit (filter) that is tuned to allow ONLY very high frequencies (in the MHz range) to pass. The spike doesn't count as a very high frequency. It is one event. Not to mention that car alarms work with hopping frequency remotes to protect the car from thieves that could "record" the signal for unlocking the car. Furthermore, there are many decoupling capacitors on the power supply inside the alarm. They should do just that. Shield the circuits from any spike transferred directly through the alarm from the car electric circuit. What happened in your case was that some capacitors are old (20 years!) and they have lost the capacity to filter the power line as good as before. I can guarantee that if you re-cap the alarm, it will work flawlessly another 20 years. Therefore, I'd say that unless the inner circuits of the alarm are directly exposed to a very powerful, variable and high frequency magnetic flux, nothing will "trigger a specific part of the circuit" in a parasitic way by means of induction.

@Raychev05 car is L&K. How many Felicias had engines with Power Steering AND Air Conditioning from factory?

You missed the important part. Yoss referred to 1.6 engines, you talked about 1.3 engines. As for the age of the topics, you are free to post on 10 years old ones if you like. Knock yourself out.

Is it a special engine in limited series just for L&K Felicia??

As an electronics engineer I am not sure about the physics behind your assumption. I know you love your car and you maintain it very well, but let's not misinform the forum fellow members.

Some 990 days ago, Papez said (once) the interval is approximately 10,000 miles which is more or less 15,000 km.

@Raychev05 Are you sure you have a Felicia engine and not a Fabia one?

Never had any issue with original NGK spark plugs.

Some 630 days ago, Yoss referred to the VW engine (AEE) mounted on his Felicia 1.6...

Laserline 989SK alarm has a very convenient keyed switch to cut the power to it. No need to mess with any fuse.

Ok haha.

It is not clear if you're talking about the coolant temperature sensor (pushed in the thermostat housing and sealed with an o-ring) or about the radiator fan thermo-switch (screwed in the lower part of the radiator).

Most probably that has to do with writing chat-style in one single long sentence, no punctuation, no capital letters at the beginning of a sentence, etc Now really... you call that a clear answer? All I've asked was a simple thing. turn the damn alarm off and leave it off. By "off" I mean no power source to it. Or even better disconnect the connector from the alarm. As a conclusion, although you had your doubts (not sure what they were based on) that it wasn't the alarm having issues in relation to sending parasitic lock commands to central locking unit, it was exactly like I suggested (Papez too indirectly). I have explained why that happened, why it could happen again, and how to solve the issue.

I didn't say to turn the alarm off and on. Even so, turning the alarm off and on equals to a reset. Why would you doubt it wasn't that the problem? I would not enter into details (for now) about the alarms but as a comparison, haven't you ever seen a computer that "hanged" in an uncertain state and you had to push the reset button? You didn't tell us what happens if you turn the alarm off and LEAVE IT OFF. If the issue disappears then you know for sure it's the alarm that acts up. That would need to open it and have a visual inspection. Most probably you'll have to replace some electrolytic capacitors that got old.

Most probably.

This video should give you an idea.