Hi All,

I posted this on the electrical part of the forum and got no answers (51 views) so I thought I would post here.

I've installed a GM TBI EFI on my vehicle and have been using the GM electronic module to trigger the standard coil. I've been have some tach problem (erratic and high) so I'm trying to solve that and kill some other problems. I've decided to replace the standard coil with the Standard DR35 discussed on this forum. I've bought one but there is no pinout on the 4 connections on the coil. I can probably figure out what is what but it would make me feel better if someone who has already done this would show me what the correct connections are (ie. +, - , Tach ). Since this coil normally has a single connector that plugs into it. I guess they figured you couldn't plug the thing in wrong and didn't bother marking the coil or provide any literature that shows the connections.

Thanks for the help.

Do you have an multimeter? If so you should be able to determine which contacts/pins are electrically common and which are connected to the coil windings. Now if I could only recall which terminal grounds the secondary winding we could also determine the polarity. Actually, the polarity should be the same as a standard coil which is marked and you do own.

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Joshua

There are four terminals, but they are paired, so there are really only two. As you look at the coil with the spark output tower upright and away from you, the two terminals on the left should be negative, and the two on the right should be positive.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

On a TBI coil......one is for tach (white) one is for 12v (red)......on the other side are 2 that connect to the module. The connection between the coil and module is a premade 2 wire harness(.recommended)

The tach and 12v are separate wires in a common connector....can be a spade connector

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Thanks

SlantSixDan that is exactly what I was looking for. You mean the coil is laid out like this.


````` Spark Lead
``````(------O -------)
````(.........................)
```(............................)
````(........................ )
`NEG (_--______++_) Pos

This is a top view.

I appreciate your help.

SlantSixDan -- Now I'm confused. I've continued to look around the web for information on the coil and found a picture on the Autozone website that show the connection to be exactly backward to what you sent me. I already have the coil mounted and the the vehicle runs fine. In fact, all coils will work either way, it just a matter or polarity. If the polarity is backward, the spark is jumping from the outside electrode to the center electrode. This is the opposite of what you want. Since the center electrode is much hotter than the bended electrode (body side) it's easier for the electrons to jump from the hot metal to the cold metal (since they are already excited by the higher temperature. It takes about 15% higher voltage to make the backward jump. This is fine as long as the system can supply the higher voltage, but at extreme conditions the voltage may not get high enough.
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I guess I'll just have to run the old pencil test to make sure the polarity is correct. If you haven't heard of this test - google pencil coil polarity - and you'll get several hits that explain how to conduct the test.
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I'll let you know what I discover. Thanks again.

Hey Thezz
I would like to see your results.
Frank

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