Does anyone have any info about the pins on a 1998.5 OBD port and where the wires go. I.E. Where the chassis and signal ground go. Im trying to diagnose a faulty smarty cable or faulty obd/truck wiring. I have a 2002 ecu and a rebuilt 1998.5 ECU. I purchased a flash file from smarty to flash the 2002 to my 1998.5. IThe smarty would connect to the ECU while it was connected to the 2002 donor truck. IT wont on my truck. It wont connect to the 1998.5 or 2002 ecu while on my truck. I can hook my scan tool up to my truck and it will connect to both and read codes on both? SOOOOO I think something might be wrong with my obd port.

So how do I diagnose if it it the pin or the wire or my pcm c3 hconnector?

18 minutes ago, jlbayes said:

Both, it is a generic diagnostic.

 

You are still measuring high resistance in that circuit. 1 on a low scale of a boat load of different dmm's signifies the circuit is open. It is pin 36 or 38. That diagram is fuzzy af. Pin 38, confirmed on my OEM diagram here at work. 

 

It still does not change the fact you have high resistance between the pcm and the obd connector. 

 

pin 7 to pin 38 is 00.4 on 200 ohm setting. So the connection issue is between the pin 14 on obd port and pin 27or is it 29) on c3 connector

Pin 14 to pin 27/29 reads no ohms or voltage.

On the chart it shows 29 sci recieve on pcm for diesel. so pin 14 to pin 29 has a short or broken wire somewhere along the path?

Okay on the driver side of the firewall there is 3 connectors. All 3 appear to merge the main harness to the pcm. Is this correct? If this is what connects the pcm to the obd port which connector of the 3 would have the c3 pin 29 wire connected to it? I could probe there and tst for current If no current then I will try to get a new wiring harness from the donor truck to replace.

I have a white with purple stripe in the number 14 pin on my DLC/OBD port? It says it is supposed to be white and pin. Under the hood I located a white and pink wire.

Pcm connector C3 is the one closest to the right fender when looking at the pcm.

 

Look at the diagram.....pin 14 and pin 29 are connected. Pin 7 and 27.

so do i follow the steps you provided still? using the pins you provided that are connected?

4 hours ago, jlbayes said:

Pcm connector C3 is the one closest to the right fender when looking at the pcm.

 

Look at the diagram.....pin 14 and pin 29 are connected. Pin 7 and 27.

 

Okay 14 to 29 reads 00.3 on 200 ohm setting and 7 to 27 reads 00.3 on 200 ohm setting. I will double check to confirm readings. Double checked readings and it is confirmed 00.3 on both reads. Checked voltage with key off and they both read 0 volts. So my readings before were inaccurate as I was using the wrong pins on c3 connector...My c3 connector has pins labeled by numbers but the form/stamp/mold put the numbers slightly off center so I was reading pin 30 and pin 28 instead of 29 and 27.

Pin 7 to 38 reads 00.4 on 200 ohm setting aswell.

Anyone have any ideas? 

Well my truck left me stranded at college for a few minutes and upon inspection it turned out to be my driver side positive cable was loose. There was a small puddle if you will below the cable end and it was aluminum i believe from the better post. So now im trying t o figure out a good way to replace that battery cable end with a new one. maybe that is my problem? one can only hope!

10 minutes ago, Waydin_Stewart said:

There was a small puddle if you will below the cable end and it was aluminum

 

Nope, that's a puddle of melted lead terminal from loose connections. You want to get military terminal like I've got pictured below and replace any and all lead that have corrosion in the copper. Once you get all new cables from a welding shop just either solder on new lugs or crimp them on. So you should have what's below.

 

I have one of those terminals and the cables dont look to be very coroded inside the insulation. The terminal itself is wore out form being taken on and off so many times. I have my airdog and quadzilla terminals hooked to that battery terminals so I will have to add those on there too. Nowhere around here sells those lugs they only sell ring terminals for like $3 a pop

On 11/1/2017 at 9:24 AM, Mopar1973Man said:

 

Nope, that's a puddle of melted lead terminal from loose connections. You want to get military terminal like I've got pictured below and replace any and all lead that have corrosion in the copper. Once you get all new cables from a welding shop just either solder on new lugs or crimp them on. So you should have what's below.

 

 

I just ordered one identical to yours just now. What size is the main power wire on that terminal? I found a crimp connector that fits the small wire going into the fuse box.

is it 2/0? 

Not mine... Mine are still factory terminals.  

 

I've never had to clean mine or remove them but to change batteries back at 2012... So it will be roughly 2022 when I remove my terminals from the battery again.

 

Secret... Keep your terminals damp with engine oil they will never rot.

2 hours ago, Mopar1973Man said:

Not mine... Mine are still factory terminals.  

 

I've never had to clean mine or remove them but to change batteries back at 2012... So it will be roughly 2022 when I remove my terminals from the battery again.

 

Secret... Keep your terminals damp with engine oil they will never rot.

so that picture you just sent me isnt your terminal? sell either way i ordered one like it earlier. I just need to know how big the power cable going to the starter is to order one of those lugs for it. i read online it is 2/0?

I think that what it is. Being I've still got my factory cable in good condition I've never had to replace the cables. Sorry I don't know the size right off hand.

I just replaced all of mine with the military style connectors and 2/0 welding cable. That is bigger that stock but how much I dont know. Bought everything on line for less than $100 except the terminals. It is cheaper that way though you will end up with some extra ring terminals. Not a bad thing to have laying around the shop though. Just Google welding or battery cables and you will find what you need.

 

One day I will be as good as @Mopar1973Man and never wear anything out but I will have to buy another truck and start over. But one way or the other I will beat him back from the MOON. Ahh ha haaaaa!!!!

Edited November 3, 20177 yr by dripley

So the positive lead going down to the starter isn't 2/0 gauge wire? It's is just 0 gauge or maybe 2 gauge? I just don't want to buy a cable lug too big or too small.

Definitely not 2/0. Mine is now. Bought all 2/0 to make the install simple for me. Measure the cable and deduct for the insulation. In other word make an educated guess.

You can make your own lugs any size you like by using copper tubing / copper pipe. If smaller gauge I insert a 1/4 inch drive ratchet extension in one end of 1/4 or 3/8ths inch tubing and flatten the other end of the tubing in a vice. Drill hole any stud  size in flattened end. Advantage is I can make a nice beefy lug and wire crimp that really holds the copper wire. I also know that I have good copper that way and not something don't know about.

 

Larger needed lugs I go to half inch copper pipe with half inch extension or whatever steel round stock fits in the end when flattening in the vice.

 

I get the copper pipe from my plumber who leaves the waste laying around on my jobs.

Edited November 3, 20177 yr by JAG1

My starter cable ended up being 2/0 and everything else was 4 and 1/0 gauge. I replaced all the terminals except the passenger negative which is still a good tight clean connection. I clean all the terminals, dielectric grease on posts and terminals inside and out, alternator went out 3 days ago and after oreileys machine testing good and it leaving me stranded once again they warrantied it and bam my gauge reads 14 now instead of 12 like it did for a year. I haven’t tested the smarty since replacing the alternator and terminals. I will test it today and see if i still have a wiring issue or my batteries were just too dead to let the smarty work.

Still no luck on tracking down the problem. Anyone have any idea where to start? at the ecm, pcm, obs port, a fuse? 

I figured out the problem. It was the iod fise. My obd port need some to be replaced now from poking me or so many times with my voltmeter. The abs function on the smarty doesn’t work but I’m sure it’s a fuse or a wire. Thanks for everyone who tried to help. The smarty adds so much down low responsiveness. But it is pretty Smokey now.