Hi everyone I am about to buy my first CTD and have a few question about it. First the truck is a 1993 350 CTD w/163k and the only upgrades are bigger injectors and 6 Goodyear MTR's with 4" stacks. It is in good shape at a good price. There are a few problems with it. First the valve covers are leaking just a little. I do not think it will be too hard to replace it myself. What worrys me the most is that the battery has a hard time charging. It has a new alternator and new battery. The old alternator was tested and was bad so it was replaced. Now after all that was done the owner says it still will not charge. When I drove it I had no problems with it. The service engine light was on but there were no problems going down the road. I had a friend look at it and he thinks it might be the computer. The new alternator was never tested. I am not sure what it is. If it is the ECM how much would it be to replace? Any sugestions? Thank you!

 

Valve Cover Gaskets go... it happens. The old ones stretch and 'overexpand' under heat once they get to a certain age... Shouldn't take any more that an hour to change them really

 

The gaskets don't scare me. That fix is way with in my range of ability. Electral stuff scares me. i spent a few hours reading through this forum and do you think the charging problem is the Crankshaft sensor? How can I test for that? I realy like this truck but fixing it a lot scares me. I am going to college right now and only have my tools when I am back home, ( Money is a big issue too).

 

My 92 W350 quit chargeing. After checking things out i figured it was the CPU, a mechanic friend said he had a source for rebuilt CPU's (for about $250.00) so i had him get one. I installed it, and it STILL wouldn't charge!

I gave up and took it to a Dodge dealer. They told me it was the CPU, and and guaranteed a NEW one would fix the problem. I told them to put one in, and it did fix the problem. I was lucky to get my $$ back for the rebuilt one, but i never did get my core back that i had traded in for the rebuilt!

The cost was about $700.00 for the new one!! OUCH!!

At that time i was thinking of getting rid of my pu so that's the reason i went with the new CPU, but NEVER again. Next time i'll just add a voltage regulator or go to a GM one wire alt...

Robert

 

It's very likely that the crank sensor is the problem. If not, put an external regulator on it.

 

How can I check to see if the Crank sensor is bad? Should I just replace it anyway ( cheap part?) Also I heard a few guys put on a chevy external regulator. How would I do that? Thank you eveyone for the advive on my truck. This saved me big time money!

 

For the external regulator you actually just get a dodge part. Just for like a mid 70's truck. Chevy mostly used internal regulators since the mid 70's. You can also add an internal regulator and make the existing alternator a one wire alternator. Do a search or pm 59ford, he just went through an experiance similar to yours.

 

sorr to keep shooting this dead horse but I found a external regulator. Super cheap and easy to instal, but what I can't find is an Crankshaft position sensor. Should I just run down to NAPA and see if they have one or try to find a cheaper one on the net?

 

I don't know if I would just go and replace the crank shaft sensor, there's really not much to them. I think I would verify that it is bad before you do replace it, or make sure it is hooked up and that the connection is good, and that the gap is correct. If the gap is too great it may not operate correctly.

 

Here's how the 92 truck charging system works in a nutshell, 93 should be almost the same. The SBEC (ECM) has to send an 8 volt signal to the crankshaft sensor when the ignition is in the run position. Then the SBEC watches to see a signal back from the crank sensor showing at least 300 RPM if I remember right. The SBEC then energizes the relay on the drivers fender that controls the alternator field. The SBEC also watches the alternators output voltage and turns this relay off or on as needed through it's failure prone internal voltage regulator. The voltage regulator problem in Mopar SBEC's is extremely common in all of thier vehicles. The SBEC also has control of an additional wire controlling the alternator as well.

Dodge trucks use flash diagnostics just like GM OBD I systems. If your service engine light is on, your SBEC has detected a fault in on of it's monitored data parameters. To access the self diagnostic mode of the Dodge SBEC follow this proceedure exactly. With the key inserted in the ignition switch cycle the ignition from off to the run position three times and be quick about it, on the third cycle leave the key on. Observe the CHECK ENGINE indicator on the instrument cluster, the code will be diplayed as a series of flashes representing digits. Each code is a two digit number, Example three flashes, a pause, and two flashes indicates 32. I believe each code will repeat three times, also more than one may be present. NOW, the code doesn't mean jack (Computer codes don't tell mechanics how to fix the vehicle as told in urban legend) until you verify what is actually causing the fault, and you need to have some sort of manual with a wiring diagram to chase the problem as there are year to year variations and model wiring variations in the dodge service manual.

If you can get flash codes posted I'll try to post a reply as to what they mean. If the crank sensor fails the alternator will not charge. If you can't get codes try again or do so right after the light is on. If you still don't have codes the SBEC may very well be at fault as it doesn't recognize the que to go into diagnostic mode. If you get to this point take the truck to someone with a good scanner that displays live data to verify your suspicion as throwing a computer at it isn't always a sure fix.

Yes, NAPA sells a replacement crank sensor, but they have it mis-cataloged as a vehicle speed sensor, their price is better than the local Dodge dealer.