- Joined
- Aug 16, 2017
- Messages
- 227
OK. Here's the skinny. F-21 is the actual B+ fuse, 5A for the PCM. On pin 55, you should see 12V. You must have ground on pins 3, 25 & 55. The PCM will definitely not like an open end to a 30A fuse. Fuse 26, a 30A fuse, supplies voltage, and passes allot of current to other items that are inputs to the PCM. If fuse 26 is blowing, pull all the lines from the output side of the PCM relay. Something there is shorted.
Now, I can tell you for a fact that those straps on the back of one or more heads, NEED to be connected. If you don't have those lines connected, or the grounds I mentioned above, the PCM will find its on ground, any you may not like the results. That tends to burn up PC foil on the PCM, unless the ground line, the ones above, are connected. The company I worked for added ground fuses for just this reason. It is much better to burn open a ground fuse, rather than replace burnt components, or fix burnt foil.
I hope I didn't put anyone to sleep. If you need more help, I can help you in the car, and we can go over it together. Used to do that as well.
Now, I can tell you for a fact that those straps on the back of one or more heads, NEED to be connected. If you don't have those lines connected, or the grounds I mentioned above, the PCM will find its on ground, any you may not like the results. That tends to burn up PC foil on the PCM, unless the ground line, the ones above, are connected. The company I worked for added ground fuses for just this reason. It is much better to burn open a ground fuse, rather than replace burnt components, or fix burnt foil.
I hope I didn't put anyone to sleep. If you need more help, I can help you in the car, and we can go over it together. Used to do that as well.