Gas Heater Points Service

[hundel]

Can anyone help me with access to points on an Eberspracher heater from a '73 Thing that I'm trying to service. Fuel pump tests out okay but points test fails.

My understanding from available diagrams/videos is that the red fan can be pulled to gain access to the points behind them but that's the extent of my knowledge.

It wasn't immediately apprent (to me) how the fan blade apparatus can be pulled. It appears to have a threaded steel insert at the center.

Thanks all!
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57 Diamond Green Ragtop Beetle #1286935 Eng. #1389420
59 Fjord Blue Beetle #2117358 Eng. #2447594
73 VW Thing
90 Vanagon Westfalia Bordeaux 78k mi. and growing

[SilverThing]

There are two sets of points on the heater motor. One triggers the ignition every revolution and the other is geared down to trigger the fuel pump every 33rd revolution. This service manual, while not specific to the 181/Thing/Kübel/Safari/Trekker, does show the adjustment of the two sets of points decently: https://www.thesamba.com/vw/archives/manuals/bn4troubleshooting.php I could be remembering wrong, but I thought the ignition points are under the red plastic fan and the fuel pump points are under the metal combustion fan. I also could be remembering wrong, but I seem to recall that the red fan was press fit and the threaded brass in the center allows you to remove the fan by using a screw (I do not recall what size thread it is - I feel like we found a random one on my dad’s work bench that was the right thread). The combustion blower is held in place by an allen set screw.

My personal heater’s points wouldn’t trigger the pump so my dad and I built a circuit to trigger the pump after 32 ignition pulses. We used a 555 chip, if I am remembering correctly, which could be considered period correct as the 555 chip was introduced in 1972. This solution wasn’t developed “in period”, but was back when Radio Shack was still around and had electronic components you could buy (before they went all in on cellular phones). I should dig up the schematic and post it on the forums at some point.

At the time, I had thought the nylon 1/33 worm gear had melted or gotten worn down which was causing it to not trigger the points. I have since examined the gear more closely and while there is some asymmetric wear, it is not enough to cause the pump not to work. The issue is the electric motor’s bushings have worn causing the motor shaft to wobble, which on my heater meant the pump would no longer trigger (the wobble/wear disengaged the worm gear). Maybe someone more clever than I has figured it out, but it appears to me that the bushings can’t be replaced (the carbon brushes are also not serviceable).

I’ve been wanting to see if there is a motor company that I could work with to make a repro/replacement motor with replaceable bearings (and brushes), but I haven’t had much success when I have asked around.
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"I like how everyone likes talking about Zeke's Thing yet he's the only one that's ever seen it." - Katie
"I've seen pictures..." - Jeremy

[mondshine]

The points are inside the end caps of the motor housing itself.
Just in case you want to test again before you take it all apart, here is a link to a slow motion video showing both sets of points tested.

Link