Positive to Negative Ground Issue

[Ray Smith]

Guys (and girls), I need some assistance with identifying whether or not my vehicle is negative or positive ground. I purchased this BJ7 form a broker in a non-running state. I have just completed an engine rebuild, and am getting ready to srart the engine. The BJ7 came with an electronic distributor installed when I purchased it. I have read that if the polarity is incorrect that it will destroy the electronic ignition, so it is imperitave that I know the proper polarity prior to starting. Any suggestions?

Also, I have purchased a gear-reduction starter. Does this starter install the same way as the original starter? It appears that the driving gear on the gear-reduction starter pushes out to engage the ring gear, whereas, the original starter pulls inward to engage. Am I missing something?

Thanks for your input.

Ray

 

[Michael Oritt]

Ray--

If the wire from the positive post of your battery goes to the shut-off switch then the car is positive ground and vica-versa. And though it's reasonable to assume that the PO purchased and installed the correct distributor or kit, unless you're feeling lucky you might want to identify the conversion before turning on the key (your chances are 50-50 or better that it's correct!).

The reduction starters work as you describe--they are clockable to make them fit, though not all are the same. Some slight modification to your footwell's sheet-metal
(crow-bar, etc.) may be necessary. All of the ones I have seen have built-in solenoids so consider removing your present one.

 

[Geo Hahn]

Ray -- since you had to ask I'm guessing that maybe the battery wasn't installed when you got the car. In that case I think you need to find out which polarity your electronic ignition system is expecting. Lacking any polarity marks on the unit a query to the manufacturer may be needed.

Once you know what it wants you can easily install the battery, polarize the generator, etc. to that polarity.

Yes, the gear-reduction starters usually have an internal solenoid but some folks whose old solenoid was the push-button type like to wire the ignition to the old solenoid and then from the old solenoid to the new starter to retain the handy under-bonnet starter button.

 

[Michael Oritt]

If it is not installed you might be able to tell by the size of the terminal connecting lugs which way the battery was last wired. However, it's still the smart bet to ascertain the ignition system's polarity prior to attempting start-up.

 

[Dave Russell]

[ QUOTE ]
It appears that the driving gear on the gear-reduction starter pushes out to engage the ring gear, whereas, the original starter pulls inward to engage. Am I missing something?
Ray

[/ QUOTE ]
You are correct, not missing anything. They seem to work fine even though the gear engagement is from the opposite direction. With the original, the ring gear teeth may have been beveled to ease engagement, but the now square engagement surfaces work just fine with the new starter.
D

 

[tahoe healey]

Check behind the tach. If it has been converted to neg ground they would have had to alter the dizzy wires (the loop of wire). It would have two splices on it if converted and none if still positive ground.

 

[Ray Smith]

Thanks for the input. I feel confident that I am on the correct path to firing the Big Guy.

Ray