BobOkie

So I got home earlier this week and was moving truck when things went crazy. Truck runs great but shortly after start up radio goes off, dash cluster goes dead, engine light and ABS light come on (even with - cluster dead - no rpm, speed, fuel, oil or battery signals). Codes 1694, 1693, 1687, ECU 1691, 1698, 0230. Engine runs like nothing is wrong moving truck into backyard to repair. (City has ordinance about vehicles in front have to be running).

I did a quick look at cables and connections. Everything looked ok.

So what to do. I pulled the oldest battery about 5 years old. Took it to parts store to have it checked. Battery tested good but as I am walking away guy asks other guy why battery tester is so hot. They did not give me a good feeling. Back to house. pull 2nd battery. Take both to another store for test. Result - old battery dead. Replace both because they tell you that is best and for an extra $180 I wanted to make sure that isn't the issue. Was told that a couple of years ago when I installed the newer battery but did not want to spend the money.

Got home, install two new batteries. Truck starts up and everything works like it should. Clear codes. Still have 1693 and 0230. I believe that is from the lift pump being wired without ECM. Mechanic did that because lift pump was only pulling about 10 psi - now 18-20 psi at idle.

Long story short - electrical gremlins are a pain but start with the basics and work upwards to more difficult and expensive. Also, double check stuff. As I heard once a good carpenter measures twice and cuts once.

Hope this can help someone.

2002 Dodge 2500 6 speed Cummins, 155k, FASS lift pump, fuel pressure gauge.