During the last couple of weeks I have had the SES light come on and go off on my 1995 6.5 1500. It has only done this in the late afternoon on return home from work when outside temps were 95+. It seems to come on more often around 60 mph and will often go off when you decelerate.

I have checked all critical stuff like oil, trans fluid, coolant, etc. No warnings from dash gauges, everything looks OK.

The most recent modification I have done was to remove the cat. I've had a flowmaster on this truck for several years now with no problems.

Any thoughts???

Have you checked the code yet, if you have an obd 1 its simple to pull them. I believe its covered under the FAQ.

A vehicle that I just test drove today did the exact same thing, But I have no idea what may of caused it. I did not buy the truck because of that light. It was a 1500 4x4 6.5td. Sorry I cant help more:(

No. Guess I can get it checked at local autozone, since GM charges $60.00 to run diagnostic. Thanks.

If it is the truck in your sig then try this link, it tells you how to pull the codes out. just make sure you have the style diag plug that is pictured. I know my truck did that when I first got it and it ended up being the pmd, but it did it again a few weeks ago and it was the wastegate actuator solonoid. So who knows just get a code and go from there thats all you can doa at this point is to figure out what it says is wrong and then figure out what is actually wrong.
http://www.kennedydiesel.com/readcodes.html

Take a close look at your battery cables and connections. I had the exact same symptoms and found stripped threads on one of the side battery terminals. Seems to have solved the mystery SES and some smoking. The certified gorillas at Chevy dealer are not only expensive, there incompetent.

My truck has been doing the same thing, I have checked for codes and found nothing. If anyone can solve this problem it would be great!! Mine started a while back and only did it on long trips. Now it does it shortly after leaving the drive way. Also when my light comes on it kicks my cruise control off!?!?

If the light came on, there is a code in memory.

Ok so how do I get a code out of the memory? Cause if I do what is on the Kennedy web site then nothing comes up... Do I have to go to GM for that?

[quote=mitch1000;675768]Take a close look at your battery cables and connections. I had the exact same symptoms and found stripped threads on one of the side battery terminals.

Mitch1000: When you say "same exact symtoms" do you mean SES coming on in afternoon vs morning and maybe more often at higher speeds??? I have removed passenger side battery several times doing some mods to the air box. Terminal may be stripped.

Thanks, I'll check that.

My matching symptom was that it occured around 60 mph and would go away with speed decrease. One thing I noticed was it seemed to occur during slight uphill grades on the highway. When the problem got realy bad, there seemed to be a loss of sensitivity in the throttle pedal. I used to be able to cruise at 45 mph with the slightest touch of the pedal. Finally, I had serious voltage drop as I traveled, sometimes with abrupt changes. So, I started cleaning cables and found the stripped lug. Now my light pedal is back, so far no more SES, and cleared up a slight smoking problem. My guess is that the stripped threads caused a high resistance connection and the electronics supply terminal was undervoltage, which could easily cause mysterious symptoms.

Check out diagnostic check list (link in signature line) By the time you've gotten to the bottom of the list, you may have your issue solved. If not, post your results.

Checked out battery cables (as per Mitch1000) and passenger side definitely needed some attention. Cleaned that up and drove, no SES light yet. Checked codes as recommended with jumper. Got codes 32 (EGR Circuit) and 33 (EGR Control pressure/Baro sensor circuit high). Cleared codes by depressing gas and brake pedal and get code 12 (which I understand is normal). Recranked, checked codes and only getting code 12 now. Time will tell if it was the battery cables. If not, anyone familiar with possible problems related codes 32 & 33??? Truck is 1995, 6.5 1500 (in signature).

Hooky,

I have fought code 32 and 33 MANY times before installing an F prom. The best thing to do is CLOSELY check the vacuum lines from the vacuum pump all the way back to the 2 solenoids on the drivers side valve cover. Then check from there to the EGR valve, and to the firewall mounted BARO sensor. The other thing to check is the wiring to these solenoids as it gets old and the wires break inside. Lee (0Lee) hit on a sure fire way to see if the wire is broken. If you start your truck and gently wiggle the wires to the solenoids and the motor stumbles, you know you have the broken wire thing.

I have heard of people buying the EGR wire harness, but I am hard headed and just rebuilt mine myself. I got the 32 and 33 codes to go away and they stayed gone until the day I went with the 1995 "F" prom that ignores the EGR system :ro)

[quote=nvmtnlion;677384]Hooky,

I have fought code 32 and 33 MANY times before installing an F prom.

You left me here! What is "an F prom"?

You left me here! What is "an F prom
An F prom is a chip from an F engine(heavy duty).

My work truck ('94 6.5 C3500) did the same thing and would blow black smoke. Checked codes (jumper A to B on the ALDL), it was a waste gate inefficianty code. Diaged. to the air filter being clogged. Want to know what clogged the air filter?????

A snake skin:eek: and no, I haven't found the snake yet. When I do:snipersmi

My codes were 32 and 33 also. So far no SES since fixing bat terminal, but then again, I haven't driven any substantial distance, just around town. Hauled 1615LB of stone this weekend though and no problems.

Keeping my fingers crossed that it was the terminal!!!! Cleared codes and have checked three times since and still just code 12. Thanks for your help