SUN 200 Engine tune up tester

Val

I have a SUN tune up tester and I have a question concerning its use. My car is a positive ground system. The leads on the tester that connect to the battery, would I connect them the same being red to ground and black to power?

railknight

How old is your SUN tune up tester? I have a SUN Electric "Automotive Test Procedure Manual" from 6-52.

Val

I believe it's a 1952 unit

Val

This is the unit

railknight

Wow! That's a nice old unit. I hope it all works. I have several individual SUN electric testers in nice condition from the late 1930s and early 1950s that are basically just display pieces in my garage. Anyway, this might help you regarding your concern for hooking up your test equipment. Under, "General Starting System Specifications," on page 107 it reads as follows: "IMPORTANT: All illustrations of starting motor and circuit tests show the leads connected for a NEGATIVE grounded system. Reverse the position of the red and black leads when testing a POSITIVE grounded system."

Val

Yes it does all work as I have seen it in use. A member of my local chapter had it and gave it to me. So if I understand you correctly, I hook it up as the car is meaning the red lead will go to the positive post on the battery which is ground and the black to the negative post which is power.

railknight

Yes, Val, for example, when I attach my 6-volt "Battery Tender" charger to my Hudson, I attach the black lead to the 6-volt battery negative post and the red lead to one of the bolts for the thermostat housing as my 1953 Hudson's positive grounded as it came from the factory. Also, the 1952 Hudson Mechanical Procedure Manual has many illustrations, especially in the chapter labeled "Electrical System," with the actual SUN diagnostic instruments showing how the cable lead clamps are attached to whatever electrical system you wish to test. In fact, a few of the illustrations should look mighty familiar to you as I believe they show the type of SUN instruments you have.

The SUN Electric testers I have are a dwell-tach-tester, battery-starter-tester and a coil tester (I also have one of their classic red plastic, pistol shaped, timing lights with its original box). These testers are all the individual type that are more horizontal shaped with the handle as well as hook to hang from the underside of the engine hood and then attach the various electric leads. The battery-starter-tester has a voltmeter which I tested against a modern one, and it still gives a good reading. But just a little warning here for anyone reading this as I read somewhere that these older SUN testers may not be as reliable or not reliable at all due to age and/or perhaps how they were stored in their lifetime being exposed to high heat, cold or both. That said, Val, it's great to know that your SUN equipment still functions today as it did back in the day.

It may interest you to know I grew up as a young kid of the 1960s not that far away from the SUN Electric factory that was located at Harlem and Avondale in Chicago. In fact, one of our neighbors worked there for a while. They were well known for making car racing tachometers at this time and I heard that one of her sons wanted one of these tachometers for his own car. They just grabbed one from their inventory and gave it to her. Oh, to get one of those vintage, racing "tachs" today for free!

Dan

Val

Thank you so much for the explanation. My 39 is positive ground so I will hook it as you say. I appreciate you very much. The timing light on this one is of the older style the flashlight shape. Never used on like that before.