Distributer body continuity

R

Ralden

Junior Member
I don’t show continuity between 2 of the 4 paths in the body.

The car is currently not running as I’m getting fuel, and spark cleaned up for a first start.

There are no visible cracks or defects in the body, and I would think that under working conditions the spark would travel to the plug, but I would like a more experienced opinion.
 
It is probably best to replace the distributor housing (body). Although it may run because the voltage coming from the coil may jump any gaps in the housing paths, it may not run at its best. The contacts are usually oxidized so it may be that the probes on whatever you used to check the conductivity did not break through to metal. In which case you may want to file a little bit of the contacts for good contact and try again. But try the original housing before buying another one.
 
I agree with NK. Make sure everything is clean and dry. Sometimes folks grease the slot in which the upper plate turns, and that can lead to gaps in continuity between the upper plate and the body. Also look closely at the wire going from the lower plate to the points, that sometimes gets broken internally. Finally, paint can be an insulator, so be sure your probe tips are contacting metal. Be sure you remove and test the condenser before testing, if the condenser is shorted internally then that will horse up the internal isolation you are looking for.

Which paths are you having problems with?
 
Rotor Gap 164kb.jpg
 
I have had the same problem visually the body looked perfect .Changed the body misfires cured .

John in autumnal Suffolk County England .Sunny Chandler AZ next week . My trailer misses me !!!
 
I obviously misunderstood - I thought you were talking about the metal distributor housing, not the plastic (Bakelite?) body.

As others have suggested, replace it and move on.
 
To me, the distributor cap is a two piece cap. The body is the cast iron housing. The lower cap has it's internal insulated high tension pathways and the upper cap has the brush and the high tension input terminal from the coil high tension lead. The rotor has a little gap that the high tension voltage has to jump a little bit between it and the lower cap pathways for the passage of spark so it's important now much gap there it between rotor and lower cap. If there is no continuity in the lower cap pathways then the cap is scrap and should be replaced.

On the distributor housing (or body), a person needs continuity between the block and the housing for good ground path of the breaker points. The wire that runs under the rotating breaker plate to the Electro-Lock terminal plate also has to have continuity for the distributor beaker ground path. The Electro-Lock assembly needs continuity when the switch is on and the wire from it to the coil needs continuity to complete the ignition circuit ground path.

If it's high tension pathways that the OP is questioning in his first post, then it gets involved with the principles of high tension voltage. A high tension pathway can function normally with gaps in it but too many gaps will make it more difficult for the voltage to jump those gaps. Normal gaps are the one between rotor and lower cap and the one at each spark plug. Any other gaps are not normal.
 
rotorwrench said:
To me, the distributor cap is a two piece cap. The body is the cast iron housing. The lower cap has it's internal insulated high tension pathways and the upper cap has the brush and the high tension input terminal from the coil high tension lead.
Click to expand...

Most Model A parts vendors call the upper cap the "Distributor Cap", The lower cap the "Distributor Body" and the cast iron body the "Distributor Housing".
 
Some of the custom dual coils set ups used on the later crab type V8 distributors had two caps. The rabbit ear set up from 1946 through 1948 has two stacked caps. The divers helmet distributors from 1932 through 41 had a right and a left cap. This is why I look at it this way. Ford had a long history of multi part distributor high tension caps with only a few exceptions.
 
rotorwrench said:
Some of the custom dual coils set ups used on the later crab type V8 distributors had two caps. The rabbit ear set up from 1946 through 1948 has two stacked caps. The divers helmet distributors from 1932 through 41 had a right and a left cap. This is why I look at it this way. Ford had a long history of multi part distributor high tension caps with only a few exceptions.
Click to expand...

Understood. Even my '81 F-250 has a two piece cap. But they call the top a "Distributor Cap and the Bottom a Distributor Cap Adaptor. But I thought we were discussing Model A's on this thread...
 
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Hello, if you are talking about a repro distributor Bakelite body , think there was on earlier Ford Barn post about issues with them . Check continuity on all of the contacts before installing, repro parts strike again! Also as mentioned in posts inside the metal body the wire connecting the lower to upper plate will work loose and cause intermittent problems, have seen that a few times.
 
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