6.2 electrics help

[AdamY]

Hi - after a bit of help in identifying three electric units on a 6.2 Chevy G20.

Van has not run for some time and some of the wiring is not good. Anyway - having problems in getting it back to life and be good to know what these units do!

Two Bosch relays and a third white unit?

Unfortunately electrics are not my strong point - so any help much appreciated.

Thanks

[bmoeller]

The white unit is a circuit breaker (with one terminal missing). Looks like something added, perhaps for extra lights or some other electrical feature.

[DmaxMaverick]

That setup is not OEM, so you'll have to chase the wires to find out what their (intended) purpose was. It could be anything, really.

[AdamY]

many thanks for replies - certainly does not seem anything too important to worry about at this stage.

I will have to get to the bottom of the wiring one day though......

[Dvldog8793]

Howdy
All of the pictured items appear to be add-ons and not factory. For the relays, you can trace the power wire back to whatever it is powering to find out what it does. Most likely something that was added, like lights or aftermarket stereo ect...These relays can be wired a couple different ways so without looking at it, hard to say what wire would be doing what.
Basics-
one wire will be power source(battery or fuse panel and should be fused), one wire will be chassis grnd(earth) this is the wire that goes to the mounting stud
One wire will be a signal wire that opens or closes the relay(might be a switch or the ignition or a sensor)
One wire will be the accessory that is powered by the relay

The white box appears to be a thermal breaker(???) It also appear to have one terminal broken off so I would say it is doing nothing...

A couple of things could be creating a starting issue for you:

--If this vehicle has ever had an alarm system or a remote start installed, and these relays/breaker are part of that.

--If the glow plug system was modified in some way and they are part the modification.

Once running, these engines need minimal electrics to function...only one wire to the pump I think.

Hope this helps....
Good luck!

[Dvldog8793]

Howdy again...
FYI-
The relays are grounded(earthed) to the mounting bracket. It also appears that some other items are grounded to that as well...these would be the other wires that are hooked up to the mounting screws of the relays. If that bracket is not securely mounted to the vehicle electrical ground system then you will have problems with whatever those other wires are hooked to.

Also it looks like your battery cables might need some attention. before you start doing any electrical trouble shooting I would address the battery cables and battery connections. Make sure all the grounding cables and grounding straps to the body are in good condition and that mounting points are clean.

[AdamY]

Many thanks - actually got her running again last night!

Not quite sure what I did - guessing found a bad earth. But really good to have it running again - been 8 years since on the road and probably 3 years since it last ran.

Moved it to my home and really pleased how nice it was to drive again. So much more character than my Ford (european) pick-up truck!

Now onto restoring / improving......