Do I need a ballast resistor or not - Crane XR700 install

[Happy Face]

I'm about to install a Crane XR700. I also will be putting in a new Bosche RED coil.

the Red coil says on its label that it has 1.8 ohms of resistance.

The instructions that come with the Crane unit are unclear to me as to whether I need to bypass, or use the existing ballast resistor, or get some other model ballast resistor. There is already one on the car (its in its original OEM setup). I take it that the ballast resistor is that ceramic box located on the sheet metal, right next to the existing coil.

thanks

[BillWilliams]

designed for the red coil, took me awhile to get it.

I called Crane's tech support line and they gave me the resistance required for the XR700. I forgot what they told me, suffering from CRS

[Happy Face]

Bill

Since you had a successful install, did you actually drill a hole in your old distributor cap per the Crane instructions, and use a timing light to spot the rotor? They suggest that you drill a large hole, use the timing light to make sure the rotor is timed correctly, and then go and by a new distributor cap to replace the one you drilled a hole in.

Is this really necessary?

[BillWilliams]

I was thinking about two days ago, since I suffer from CRS, I do not know.

I can't remember doing that, I believe the guys on the tech line told me I did not have to do that. I remember doing something like rotating the rotor until I saw a spark from a grounded plug and went from there.

Sorry I am no help, maybe Matthew Cervi can jump in. He is a smart guy and just installed a Crane.

[PSloan]

See if you can contact brian mcdonald he has one on his car.

[MatthewCervi]

Wish I was smart enough to burp the cooling system...but that's another story.

I just installed a XR700 and did not phase the rotor (i.e., drilling the hole in the cap to align), all I did was tweak the optical unit back and forth while watching the LED on the Crane unit and then tightened everything down.

Also, I recall the instructions for the XR700 saying it needed 1.8 ohms resistance from the coil. I got the Crane coil and it measured 1.8 ohms and the instructions explicitly said you don't need to add an external resistor with that setup. If the red coil is 1.8 ohms also (and I'd measure to confirm) then I think you'll be fine.

[Guest Anonymous]

If you need 1.8 ohms resistance, why can't you go to radio shack and buy a 1.8ohm resistor of some type and place it inline, rather than spend $40 for the part from BMW??

[polloelastico]

I have that installed with a red coil and did not use a resistor, works great.

[polloelastico]

If you need 1.8 ohms resistance, why can't you go to radio shack and buy a 1.8ohm resistor of some type and place it inline, rather than spend $40 for the part from BMW??

And if you want to use the resistor, go to a napa, they have them for about 10 bucks.

[jpcapoc]

I installed an XR700, and I did not need to drill a hole in the distributor cap. Here's what I did. Before installing, I got the engine to approximate TDC on #1, and noted the position of the rotor in relation to the little notch in the distributor body. After installing everything, you can then rotate the distributor body until the light on the module body comes on. The directions tell you how to do this. When the light comes on, you know you're firing at approximately TDC. Advance it a couple of degrees prior to attempting to start the car and it should fire right up. Then you can time it the normal way using a timing light against the little ball in the window.

I'm using the original ballast resistor, which is the ceramic thing near the coil, I have a red coil, but I don't think it's a Bosch! If I remember correctly (I too suffer from CRS), the instructions said something about the module overheating, with or without the resistor? but I don't remember. Since mine did not get hot, I left well enough alone.