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Heater stopped working


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Hey guys,

I got my 85 FrankinSoob GL, my heater recently went out. I was wondering what the most common problem is that could cause the heater to stop before I tear into it. For a while I had to play with the buttons turn them on and off until it would come on. But now no matter how much I mess with it, it does not work. The fan motor seems pretty simple to get to, but before I tear apart the dash, is there any I should check first? All the fuses are fine. I noticed the selector switch is vacuum based, so where is the vacuum actuator that runs it. Any control relays I could check? Lemme know what your experiences with this. 

Thanks,

Daniel

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From memory there are three vacuum actuators on the heater box. Two on one side and one on the other. 

Make sure the vacuum line is connected at the engine and it isn’t split. 

As for the fan issue, I’ll leave that one to someone else - I’ve got an L with the same issue but can’t work it out either. 

Cheers 

Bennie

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1 hour ago, DaveT said:

Are you not getting heat, or is the blower not spinning?

I'm not getting anything as of now. It used to work great, then I started to have to play with the buttons and turning the on and off to get it to work and the defrost selection stop working. Now it doesn't work at all.

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4 hours ago, el_freddo said:

From memory there are three vacuum actuators on the heater box. Two on one side and one on the other. 

Make sure the vacuum line is connected at the engine and it isn’t split. 

As for the fan issue, I’ll leave that one to someone else - I’ve got an L with the same issue but can’t work it out either. 

Cheers 

Bennie

Where are the actuators located? And what line connects to the engine. I have a swapped 2.2, but it has worked since I swapped the engine.

 

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The buttons work valves in a vacuum system that moves doors to rout the air to different vents.

Temperature slider moves a blend door, via cable, that directs 0-100% of the air through the heater core, which is always heated by engine coolant. 

 

The vacuum system is fed from a small tank, white plastic, or older ones might be a black ball shape, over on passenger side under the hood.  One small line goes in to the button assembly.  You should hear hisses and things move if you change button settings immediately after shutting off the engine.

I don't recall where the contact for the blower motor is, but also be aware that the lower speeds often stop working due to the resistors burning out.  They are on a thing down by the motor, in the air path, with 4 wires connector.

 

 

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You have no fan blower operation at all?

As well as not getting any hot air coming through?

What about some heat at least from natural air flow when driving at highway speeds?

If you have no fan blowing at all chase this problem first.

I had rainwater get in through rust holes below windscreen, that made its way via air cooling elbow duct aimed at fan motor brushes , corroding things up

Ended up deleting the fan air cooling of the brushes tube just in case more water got in. Replaced fan motor worked forever after

Those buttons on dash binnacle you press to change air flow blow direction - each one at the back does the vacuum valving switching and are well designed and made, I have never had a problem

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1 hour ago, ClassySoob said:

Where are the actuators located? And what line connects to the engine. I have a swapped 2.2, but it has worked since I swapped the engine.

On the RHD vehicles there’s two on the RHS and one on the LHS from memory. They sort of look like an accordion tube with a metal rod on the back end that pulls on the lever. 

On LHD vehicles these might be swapped around. 

Remove the kick panel above the driver’s feet and pull the glovebox out - this will allow maximum access to both sides of the heater box. From here you can work out where the bits are that you need to mess with. 

There will be a vacuum hose from the intake manifold to the vacuum canister that DaveT talks about. Check to make sure this is still connected at both ends and doesn’t have a split in it. 

As Steptoe said, I’ve not had a problem with the vacuum switch panel in my L series. 

The fan could be a series of things - fuse? Check first! Next would be the resistors in the air duct for the different speeds. But if these are the issue you’ll usually have off or full speed without one or all other settings. Or your fan is toast. Or there’s and issue with your fan switch. Or there’s another issue at play. 

All the best with it mate. 

Cheers 

Bennie

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