Left charger on car with the key on for a couple of days. Big mistake. Found that the rotor, dust cover and cap were toast. Replace those items and still wont fire up. Any ideas. The electronic pick up wasnt melted but could be bad. Any ideas out there?

 

Need a little more info what model XJS V12 I6 ignition type, There are many different models Opus, HEI and Marelli for the V12 I don't know about the I6.

 

thanks for the reply. 87 V12 HEI with lucus distributor. Also, could the voltage booster be the culprit. Can it be tested as well as the pick up module in the distributor? Really appreciate the help.

 

the two coils checked out good.

 

The ignition amp GM module is probably shot. Just a guess.

 

You will need to check for melted wiring in the HT system and HEI module, if the rotor has melted there was significant current flowing in the system. It is also possible to fry the ECU if you leave the battery connected and then add the charger, depending on the type of charger. I always leave my XJS on trickle charge but remove the battery neg terminal before I connect the charger.

Can you measure the voltage (on the low voltage side of the coil)
a - across the coil + and - terminals
b - from the + terminal to earth
c - from - terminal to earth

and post back

 

thanks warrgon. Sorry but not sure what the HT system refers to. Explain? Will measure the voltages on coil and get back later today. thanks

 

"HT" = High Tension = the high voltage side of the ignition. Coil output, distributor cap and rotor, plug wires.....


Sometimes referred to as the "secondary" side of the the ignition system, with the "primary" side being your low voltage stuff: wiring to the coil, breaker points (remember those?), ignition modules, etc.

Cheers
DD

 

High Tension, DUH, Should have known that. Got into the habit of calling it High Voltage side. Thanks.

 

Warren, finally got the voltage measurements you asked for. With the key on and a hot new battery the readings are:

on the coil, positive post to the negative post = 0
positive post to ground = 12 volts
negative post to ground = 0
Hope this helps. Thanks a bunch.

 

This sounds like your ignition module maybe suspect. Can you connect the meter between Coil Negative and the positive battery terminal, the meter should read 0 Volts, crank the engine and the voltage should rise to about 2-3Volts.

If this is ok disconnect the wire at the coil Negative turn the ignition on and measure the voltage between the coil negative post and ground, you should have 12volts.

 

Ok. sounds like we are on to something. Since the battery is in the trunk, I will need to add a extension to the volt meter lead but will figure out something. Will let you know. Triple thanks Warren.

 

Use a set of jumper leads or a big thick cable.

 

Warren, cked the voltage from the neg on the coil to the pos. on the battery and got .03 volts ( probably 0 ). When cranking the engine the reading read about .5 volts. Hopes this help. Again, thanks.

 

This sounds like the ignition module is faulty. I don't have any experience with these but I do know it's a GM HEI unit.

Can someone suggest which GM unit will replace it...