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1st Gen Ram Tech'93 & older Rams: This section is for TECHNICAL discussions only, that involve 1993 Rams and older. For any non-tech discussions, please direct your attention to the "General discussion/NON-tech" sub sections.
I decided to change the ECU back to the one that came in the truck that I replaced the capacitors in.
what is the specs of the large capacitor? i got a computer i think i need to replace the capacitor in but i don't remember seeing any specs on it and i am pretty sure it is bad. already replaced the switching transistor which got me spark but guessing the bad cap is what caused the old switching transistor to fail.
Well that wasn't the problem apparently. It also took AAA 4 hours to get a towtruck to you in Burbank CA. Cranks over, no spark. I checked with a meter and the ignition coil is not getting power with key on or cranking. Anyone with ideas please let me know where to look. Thanks
what is the specs of the large capacitor? i got a computer i think i need to replace the capacitor in but i don't remember seeing any specs on it and i am pretty sure it is bad. already replaced the switching transistor which got me spark but guessing the bad cap is what caused the old switching transistor to fail.
The large capacitor I used is Panasonic FM series 25v 470 uf low impedance. x1
the smaller ones are Panasonic FR series 25v 220uf ultra low ESR x2
Cranks over, no spark. I checked with a meter and the ignition coil is not getting power with key on or cranking. Anyone with ideas please let me know where to look. Thanks
how are you testing for power? have you also checked for power at the asd relay? i would also maybe suggest trying to bypass the asd relay for testing purposes.
Does the 1993 still use a ballast resistor? I know OBD II doesn't. That ballast resistor was prone to failure and back in the day I always carried a spare wrapped in a towel in my tool box.
No ballast resistor.
As fas as the ASD, the relay works and gets power with key on for 2 seconds on pin 87, then shuts off .The fuel pump relay has power and works also.
I can hear the fuel pump and I checked the pressure at the rail again and it had 34 psi at key on.
Is there a possibility that the ignition switch could be a problem? As I said this truck is mostly original as far as the wiring and mechanical parts. The fuse box looks good and no sign of burnt wires or burnt fusible links.
if it was a bad ignition switch you should be able to bypass the asd relay and get it to fire up when you have this issue happen. i would almost wonder if you had a fusible link going bad. it is fine when cool but craps out as it has power flowing through it and warms up.
could also install a couple test lights in the cab connected to the asd relay and see which of the 3 is cutting out.
Last edited by crazzywolfie; Oct 5, 2023 at 03:24 PM.
