OT: Question about auto electrical test device
 

A friend gifted me with a vintage Heathkit auto analyzer unit. It's in very nice shape and has all the test leads and accessories that came with it along with the instruction manual. My question is, can I use this tester for my 6 volt positive ground vehicles? I would appreciate some guidance from our more electrically gifted colleagues here on The Barn.

Re: OT: Question about auto electrical test device
 

The manual may give guidance on positive ground cars. Also 6V vs 12V. Hopefully there is a switch somewhere to change between 6V and !2V.

Re: OT: Question about auto electrical test device
 

Herb,
It does have capabilities to read and measure 6 volt values, but no mention in the manual about using on 6 volt POSITIVE ground. It can test a lot of things including condensers. I want to be sure about how to use it under those circumstances and not do something wrong and damage it.

Re: OT: Question about auto electrical test device
 

If you plan on using it on the Model A. Connect the red, positive lead to ground. Use the black negative lead to measure voltages. Off the car, using the resistance scales, it won't matter which lead connects to what.
Hope this helps.

Re: OT: Question about auto electrical test device
 

Yes, your info is very helpful. Thanks! My electrical knowledge and skills are not as proficient as I would like, but I know that there are nuances with certain electrical test equipment that can end with catastrophic results if connected wrong.

Re: OT: Question about auto electrical test device
 

Check your book, it may have an internal fuse to protect it.

Re: OT: Question about auto electrical test device
 

Every time I but a used instrument I hear "it works great, I just no longer have cars without the computerized system". And every time they are inoperable. Seems anything that tests automotive voltage ends up getting plugged into a wall outlet, and that ruins it. First thing to do it put it on voltage setting, and connect the red, and black lead to your modern car to see if the voltage test works. Should show between 12.8V to about 14.2 volts. If the voltage test doesn't operate walk away, even if the seller says "ten bucks".

Re: OT: Question about auto electrical test device
 

2X Herb in Concord, Ca.

Re: OT: Question about auto electrical test device
 

Back in the '30s and '40s and into the '50s Ford wasn't the only manufacturer to use positive ground, Chrysler Corporation, Hudson, Nash, Packard and probably others also used positive ground.
On the input connections, red goes to positive, black to negative, doesn't matter who made the vehicle.

Re: OT: Question about auto electrical test device
 

Some test tools have capacitors in their circuitry and like in a lot of other older electronic gear some capacitors fail from age. The point is that while some things look "mint" the insides might not work anymore.

Re: OT: Question about auto electrical test device
 

I appreciate the very helpful information from everyone. I'll do some preliminary testing to make sure the unit is in working order before I attempt to do any real-world testing on my cars. My best guess is this tester appears to be from the 1960's, but not exactly sure.