Rwal Troubleshooting

[balaguru]

I have a 1988 C1500 that has until now been pretty badly neglected. Over the last few weeks I've fixed most of the major problems on the truck and now one of the last things to fix are the brakes.

 

What I've noticed is that the truck takes too much road distance to stop. After a little troubleshoot I've found the following: If I jack the rear wheels off the ground and let the car idle in drive, it's pretty hard to use the brakes to stop the wheels from turning. This is pretty consistent with what I feel on the street as it feels like I'm only using the front axle to brake. Until recently the insturment panel didn't even have a bulb installed for the brake warning lamp. I installed a bulb and pulled code 7 (shorted isolation valve circuit or faulty EBCM) from the controller by jumping pins A and H on the aldl. Using the info I found here: http://www.babcox.com/editorial/bf/bf50122.htm, I measured the resistance of the isolation valve to be 4 ohms which is within spec according to the link above. This link above suggests that this implies that the problem is the EBCM.

 

My question is: Is the information that I've gleaned from the link above accurate? I'd hate to buy a new controller only to find that this doesn't actually fix my problem.

[balaguru]

For anybody searching: I confirmed that the problem was with the computer by disconnecting the 4 pin connector and observed a return of rear brake power. Autozone sells a remanufactured unit for $75 after core exchange. Install was easy and now no more brake warning light and brakes work great.