blue coil, ballast resistor, and crane 700

[fjord-tii]

FWIW, IIRC doesn't the Crane instruction manual say something about hot coil and/or electronics box? I have a complete xr700 unit I can sell you at a huge discount as part of my garage clean-out, PM if interested. 

[Bad Dad]

Ran a new, thicker green wire from fuse #12 to the coil. Grounded the Crane box directly to engine block to secure a better ground. Coil still overheated and I get the same resistance and voltage readings. 
 

Note that I have no wire leading from starter solenoid to the coil, just the green wire going from #12 directly. 
 

I have noticed that my spark plug wires are very hot to the touch as well, so there’s something there. But other than that I feel I’ve tried every option. The Crane box does not get hot, so I’m pretty sure it’s the Coil which is scolding. As aforementioned, new coil did not solve anything. 

[Bad Dad]

4 hours ago, fjord-tii said:

FWIW, IIRC doesn't the Crane instruction manual say something about hot coil and/or electronics box? I have a complete xr700 unit I can sell you at a huge discount as part of my garage clean-out, PM if interested. 

It’s a rather vague manual, stating the need of a resistor, and to add one to the Crane unit if it runs hot. Not the issue with mine. It’s the coil overheating. 
 

 

[Bad Dad]

Over the weekend I was able to install a Hot-Spark unit in place of the Crane system. Feels like a new car. It ran great all weekend, with much better power in the upper end. I just finished a spirited 40 minute drive, half of it on the highway in 75mph, and when parked I was able to rest my hand on the coil comfortably—no more scolding heat. 

“While in there” I will replace all the relays, new plug wires and a silver Beru coil. In general all the electric work felt needed, but I can safely say that the culprit was the Crane unit. If anyone has a similar system and overheating coil, I would look there first. 
 

Thanks for all the guidance here, could not have sorted this without. 

[2002iii]

9 minutes ago, Bad Dad said:

Over the weekend I was able to install a Hot-Spark unit in place of the Crane system. Feels like a new car. It ran great all weekend, with much better power in the upper end. I just finished a spirited 40 minute drive, half of it on the highway in 75mph, and when parked I was able to rest my hand on the coil comfortably—no more scolding heat. 

“While in there” I will replace all the relays, new plug wires and a silver Beru coil. In general all the electric work felt needed, but I can safely say that the culprit was the Crane unit. If anyone has a similar system and overheating coil, I would look there first. 
 

Thanks for all the guidance here, could not have sorted this without. 

More junk for the neighbors pool!

[JohnS]

31 minutes ago, Bad Dad said:

 

 

I love the color of your car 👍

[Bad Dad]

Agree! Close to “Fjord” with no metallic. Have to credit that choice to the previous owner, the car was originally “Sahara”. Looking for steel wheels and some appropriate louvers for the rear window, and the car is pretty much done. 

[HBChris]

That is great news.  The Bosch red or silver coil needs 1.8 ohms of resistance or it can overheat, I found out the hard way.  I know AutohausAZ had the red 1.8 ohm ballast.

[Bad Dad]

For some reason the car had the blue 3ohm coil, and a resistor fitted. The green ignition wire had also seen better days, so I replaced that with a fresh 12 gauge. While I didn’t measure resistance on it, it looked like the “hidden” type. 

After all this my voltmeter also measures 14 now, up from mid 12 before. 

 

[Stevenc22]

Its not the hidden type. The hidden type are burnt yellow in color.

[Bad Dad]

Thanks for confirming that, Steven. You were right from day one about the Crane. And indeed the Hot Spark seems a great substitute. Until I can justify a 123 distributor, this seems a good system. 

[Chico Mann]

On 8/19/2024 at 10:01 AM, Bad Dad said:

Agree! Close to “Fjord” with no metallic. Have to credit that choice to the previous owner, the car was originally “Sahara”. Looking for steel wheels and some appropriate louvers for the rear window, and the car is pretty much done. 

I have some 13" steel wheels with hub caps I might be selling soon if your interested.

[Bad Dad]

Thanks @Chico Mann! I have been told that I need 14" to clear some Volvo brakes up front, so I am going with the E30 steelies and having them powder coated.

[Chico Mann]

💪