88 R30 wiring diagram??

[bablazer73]

anybody have access to a complete wiring diagram for these trucks? 88 R30. Loaded!!
Dealing with some harness butchery!
My truck has 2 relays on the fire wall, 1 is for the fuel pump. No idea what the other is for. Both harnesses are burnt up, and someone bypassed the fuel pump relate get the truck running.
Rockin KW came through with another engine harness, but it doesn’t have the other 3 wire harness. Trying to find out what that was for.

 

[frankin5]

It is for the 400 -4l80 trans

 

[bablazer73]

It is for the 400 -4l80 trans

Th400? No lock up.

 

[dyeager535]

anybody have access to a complete wiring diagram for these trucks? 88 R30. Loaded!!
Dealing with some harness butchery!
My truck has 2 relays on the fire wall, 1 is for the fuel pump. No idea what the other is for. Both harnesses are burnt up, and someone bypassed the fuel pump relate get the truck running.
Rockin KW came through with another engine harness, but it doesn’t have the other 3 wire harness. Trying to find out what that was for.

View attachment 304436

View attachment 304437

View attachment 304438

View attachment 304439

Link in my signature probably has it.

Just noticed signature doesnt display on my phone, if not for you as well, http://67-72chevytrucks.com/vboard/showpost.php?p=5621043&postcount=1

 

[bablazer73]

Link in my signature probably has it.

Just noticed signature doesnt display on my phone, if not for you as well, http://67-72chevytrucks.com/vboard/showpost.php?p=5621043&postcount=1

Thanks. I’ll look at it when I can open on a real computer.

 

[1-ton]

The other relay is just an extra fuel pump relay in case one goes bad (nothing plugs into it). A lot of Silverado model trucks came this way as an added luxury along with the 2-relay bracket and the under hood retractable light. Those wires are more than butchered...they are fried from a serious short somewhere in the system. I am surprised the ECM is not fried too.

 

[Abusfullofnuns]

I assumed there had been some sort of underhood fire.

 

[frankin5]

relay for Canadian Daytime running Lights per 91 Electrical factory manual.

 

[1-ton]

relay for Canadian Daytime running Lights per 91 Electrical factory manual.

My 1991 Silverado V3500 3+3 came with one of those dual relay set-ups. I did not know it was equipped with Canadian day-time running lights.

 

[bablazer73]

The other relay is just an extra fuel pump relay in case one goes bad (nothing plugs into it). A lot of Silverado model trucks came this way as an added luxury along with the 2-relay bracket and the under hood retractable light. Those wires are more than butchered...they are fried from a serious short somewhere in the system. I am surprised the ECM is not fried too.

As it turns out, the 2nd Relay is listed as a Kickdown Relay for the TH400.

 

[bablazer73]

I assumed there had been some sort of underhood fire.

No fire, but it kept popping the fuse for the fuel pump. I noticed that it had electrical tape (non factory) wrapped and it was melted. I opened it and found that mess! I just bought the truck, and am still sorting out many little issues. This being one!

 

[1-ton]

As it turns out, the 2nd Relay is listed as a Kickdown Relay for the TH400.

I am pretty sure that relay is for the cigarette lighter.