ak diesel driver
6.5 driver
too late
-
Welcome to The Truck Stop! We see you haven't REGISTERED yet.
Your truck knowledge is missing!
- Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
- We have tons of knowledge here for your diesel truck!
- Post your own topics and reply to existing threads to help others out!
- NO ADS! The site is fully functional and ad free!
Problems registering? Click here to contact us!
Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!
OPS relay install
- Thread starter Schwind
- Start date
buddy
Active Member
Your problem is perplexing. I would remove the relay protection diode and give it a try. By using the diode in parallel it bypasses the resistor. What I believe would be ideal is a resistor in series with a diode for that protection circuit.
jrsavoie
Recruit
Could somebody email me a copy of this? I tried blowing it up and it got fuzzy. I tried printing it and it came out the same size.
Probably doesn't have anything to do with not being able to see squat and being a computer illiterate besides.
Probably doesn't have anything to do with not being able to see squat and being a computer illiterate besides.
buddy
Active Member
The regular OPS mod has pics on the first page. That diagram was posted as an option to get the LP to run during Glow/WTS as well.
jrsavoie
Recruit
Does anybody sell a kit?
That way I don't have to call 20 places asking if they have relay's and then figure out if it's a relay that will work.
That way I don't have to call 20 places asking if they have relay's and then figure out if it's a relay that will work.
jrsavoie
Recruit
Sounds like a good option. In my old 89 I had a a toggle switch I would throw on before I hit the key and off after the oil pressure came up.
JMJNet
Recruit
As I posted in the other forum. Kennedy Diesel sells the kit. It is not cheap though. I have one that I bought from a fellow member a long time ago.
jrsavoie
Recruit
Thanks for the info. I haven't checked the Kennedy kit out yet. Been having enough trouble just checking the threads.
bobbiemartin
Author of The DB2 Conversion Guide
I have the Kennedy set up and it works great. It is a little pricey, but its completely plug & play. Its also nice in that it has a small button that energizes the pump. Makes it easy to prime the fuel manager after filter changes, etc.
Its mounted on the firewall, about in the middle. You do have to install a tee and a second oil pressure sensor and that is a bit of a pain. I remote mounted both of my OPS to the firewall with a hose to the block. When I remote mounted the OPS I also ran the stock wiring through a relay for a totally redundant system. I haven't yet finished the setup, but when its done I will have two pumps, each fed by their own circuit. That should eliminate any lift pump issues.
jrsavoie
Recruit
I'm just getting started installing the OPS/LP Mod. I'd say I have about $60 in it with relays, connectors and fuse holders.
I have 2 ea 20 amp fuses one between the battery and the relays and one on the way to the LP. I have a 5 amp fuse going to the glow plug controller.
Where exactly do you tie into the glow plug controller?
I have 2 ea 20 amp fuses one between the battery and the relays and one on the way to the LP. I have a 5 amp fuse going to the glow plug controller.
Where exactly do you tie into the glow plug controller?
jrsavoie
Recruit
Could I use a short grease gun flex to extend the OPS up? I have a 6 incher.
Will It have enough flow?
Will It have enough flow?
buddy
Active Member
You can use a grease hose to extend the OPS, I did it, although I used a 12" one. But it didnt ground the OPS and it didnt have the right fittings. I had to get 1/8" to 1/4" NPT fittings and then ground the OPS side of it. It was just better to get the OPS extenstion from PMDCable.com because it has the right fittings compressed on, and steel braiding through it ground the OPS side to the block side.
In the 95 did you already have a fuse that went to the LP? In the fuse center? In the 92-94, we have an LP fuse right next to the LP relay on the passenger side, but in 95 you went to the fuse center.
In the 95 did you already have a fuse that went to the LP? In the fuse center? In the 92-94, we have an LP fuse right next to the LP relay on the passenger side, but in 95 you went to the fuse center.
jrsavoie
Recruit
Which of the 3 little wires coming off the top of the glow plug controler has power while the glow plugs cycle?
Would this be a good place to get power for the relay?
Would this be a good place to get power for the relay?
buddy
Active Member
I'll have to check after work. Just pick power off the #7 glow plug wire if you like.
jrsavoie
Recruit
I thought there was an issue of using the glow plug wires being grounded after they are no longer on. Because they are like an electric stove and create heat by a dead short.
buddy
Active Member
If you are using two relays and the Glow plug controller power output to the glow plugs is just exciting a coil there is no issues. And the other way trying to use one relay the diode was supposed to protect from that being shorted to ground. Any 50V diode should have worked fine. Dont know what was blowing the fuses for Dazed, as he even said it worked fine until he started the truck. But he didnt wire it per the suggested method either, he tried to power the LP directly from the Glow Plug power and not by exciting a relay coil (although I cant explain what didnt work in that scenario either, unless the LP had some huge inrush current or negative voltage inversion of its own).
jrsavoie
Recruit
That last part was the part I missed. So I can come off the big post on the glow plug controller with no problem. One side is hot all the time and one side is only hot while the glow plugs are cycling? Correct?
I am using 2 relays. Wired as per your diagram. Thanks
I am using 2 relays. Wired as per your diagram. Thanks
buddy
Active Member
Yes that is correct, one side is hot and other side is grounded until commanded on.
The three wires that go into the Glow Controller connector are an ignition source, a ground, and a PCM signal source which you dont want to use, because you dont want to draw more current from the PCM.
The three wires that go into the Glow Controller connector are an ignition source, a ground, and a PCM signal source which you dont want to use, because you dont want to draw more current from the PCM.
turbopower6
Member
Calarfication on OPS Relay Modification
This thread seems to be revolving around pre 1996 trucks.
I have a 1996 OBD II K2500 Suburban with the 6.5 and will be replacing the OPS as a maintenance item. Since the PCM controls the LP in addition to the OPS is there anything to be gained (i.e. reducing the amp load on the OPS) by adding the relay with the built in resistor?
If I do gain by making the modification your suggestion makes complete sense if I can find the relay I am looking for. Do we have access to GM or AC Delco part numbers for these relays so we can go to a new part if we cannot locate one in a yard? I plan to use the exact color wiring that is in the factory harness: Orange and gray, so as not to confuse anything. I will be using the weather pack connectors from Delphi to make it look like the factory set up especially under the truck at the lift pumps themselves.
I am going with a re-do of the fuel supply plumbing running a Walbro FRB 5 in parallel with the frame rail factory lift pump using the 1993 higher output pump. I want to be sure I am not over stressing the electric feed for two pumps. I understand the factory frame rail lift pump is running continously when the truck is running and has oil pressure.
The Walbro FRB-5 runs when needed and responds to demand based on flow pressure. This is what the engine management engineer from Walbro told me. The new FRC units that Leroy is stocking are a continious run setup. This is the difference between the two on a basic level.
Thanks for your insights!
Ted
This thread seems to be revolving around pre 1996 trucks.
I have a 1996 OBD II K2500 Suburban with the 6.5 and will be replacing the OPS as a maintenance item. Since the PCM controls the LP in addition to the OPS is there anything to be gained (i.e. reducing the amp load on the OPS) by adding the relay with the built in resistor?
If I do gain by making the modification your suggestion makes complete sense if I can find the relay I am looking for. Do we have access to GM or AC Delco part numbers for these relays so we can go to a new part if we cannot locate one in a yard? I plan to use the exact color wiring that is in the factory harness: Orange and gray, so as not to confuse anything. I will be using the weather pack connectors from Delphi to make it look like the factory set up especially under the truck at the lift pumps themselves.
I am going with a re-do of the fuel supply plumbing running a Walbro FRB 5 in parallel with the frame rail factory lift pump using the 1993 higher output pump. I want to be sure I am not over stressing the electric feed for two pumps. I understand the factory frame rail lift pump is running continously when the truck is running and has oil pressure.
The Walbro FRB-5 runs when needed and responds to demand based on flow pressure. This is what the engine management engineer from Walbro told me. The new FRC units that Leroy is stocking are a continious run setup. This is the difference between the two on a basic level.
Thanks for your insights!
Ted
buddy
Active Member
IMO its not necessary in OBDII trucks, because you have parallel power sources during operation, the LP relay and the OPS.
The FRB5 will keep running continuously during engine operation as well, because there is constant demand. The thing is that it constantly deadheads so it may bounce from on to off, on to off like 2 or 3 times in a second while at idle, but not at all under load. When you shut the truck off is when you might actually notice the FRB5 because it will go on for a second then off for like 2 then on then off and you actually hear it because there is no demand, but the OPS still has pressure so it gets power and its holding the pressure in the lines. The stock pump you will just hear a constant vibration from for about 10 straight seconds.
The FRB5 will keep running continuously during engine operation as well, because there is constant demand. The thing is that it constantly deadheads so it may bounce from on to off, on to off like 2 or 3 times in a second while at idle, but not at all under load. When you shut the truck off is when you might actually notice the FRB5 because it will go on for a second then off for like 2 then on then off and you actually hear it because there is no demand, but the OPS still has pressure so it gets power and its holding the pressure in the lines. The stock pump you will just hear a constant vibration from for about 10 straight seconds.