glow plug relay bypass
 

Hi,

I have a 1980 4 cylinder 240d
I am wiring a bypass to the original glow plug relay and adding a interior cabin button switch and solenoid.
In the large wiring harness that goes into the original glow plug relay, I have 6 wires:
Black with blue stripe
Brown with green stripe
solid green
black with a purple stripe
black with yellow stripe
black with a red stripe

I understand that 4 are for the glow plugs but what do the other wires go to?

Would I wire all 6 wires to the other end of the solenoid, opposite the 12 volts.

Thanks.

If you are going to put a separate switch in you don't need to know what those wires are because you it can be connected direct to the battery.

This is what I did on my Volvo Diesel. I used a Ford type starter solenoid/relay. At that time, I had no internet access and did not know about the Ford Diesel glow plug relays switch are smaller but function like the Ford starter solenoid does.

Notice that there is are 2 small terminals on the starter solenoid I used. An S and I. I used the S terminal to connect the switch to.

See the wiring diagram. The switch I used inside is spring loaded. When I release the switch, it turns everything off. One thing that is different about my actually setup is I did not put a fuse in the circuit but there is one on the drawing.

My 84 300D glow plug relay has an 80-amp fuse. If you want to put a fuse in the circuit, there is 80- and 90-amp fuse setups that people that put those huge powerful sound systems in their cars use.

I only showed wires going to 5 glow plugs. On my Volvo there is actually 6 of them.

In the pic with the real solenoid the 2 skinny wires are the switch wires.

First, sorry for the double post.

I connected the bypass relay kit up and just need to finish it up by connecting the wires from the large wire harness that goes into the old glow plug relay to the new solenoid.

I have a 4 cyl 240d and there are six wires.
4 total for the glow plugs, and two other wires. The other wires I think are brown with green stripe and solid green. I believe they go to engine temp sensor but I am not sure.

Do I connect all 6 wires to the opposite of the solenoid? Or just the wires that go to the glow plugs.
Thanks.

Just wires to GPs.

Thank you.

My Vovlo Diesel had one of those silver box type relays as the older Mercedes had. They were like $240 back around 1992 when mine failed. I have not had a bit of issue from the glow plugs on it after I did the modification.

Iirc, those wires connectto the starter wiring so the relay will remain engaged during cranking and stop after cranking.

I purchased a bypass relay kit and installed it last week.
It works brilliantly and is super easy to use.

The car no longer smokes at start up, is super easy starting and is running great.

I struggled with a failing relay for a while and wish I had done this a year ago.
The only thing I don't have is the illumination of the glow plug relay light on my dash.
I am ok with that, because I now manually push a button and can time how long I activate the glow plugs before starting the car.

...And the kit was 1/4 the price of a rebuilt relay.