glow relay system diag (1 Viewer)

[daviesl]

so, my truck has been had to start for the last few weeks so I've been double glowing it. Yesterday it wouldn't start at all. I have a 3b with superglow. I know about the wilson switch mod but was wondering about how to test the glow relay, timer, and super glow relay to see if they're shot. When I turn the key the glow light comes on, the voltage on the dash just goes up to 12 and doesn't drop below. I checked the plugs and they have continuity. I checked for voltage on the bus when turning the key and no voltage, 0. I cleaned all the connections and put everything back, no change. I've read that the alt brushes when gone may cause similar readings, are there any other signs if it's the alt brushes? the pic shows the kind of attachments at the bus that I have.
I REMOVED THE PHOTO because it caused confusion

 

[daviesl]

12v

oh yeah, I have a 12v system, it cranks, just no voltage at bus. I hear a click from under left side of hood when I turn the key. the edic arm moves when I disconnect the oil pressure sensor with the key on power.

 

[Radd Cruisers]

It looks like you're missing the connection between the rear most glow plug and the power which is supplied by the bus that comes close to it below the letter W of the word Glow and in the lower part of your photo.

Other common faults:

- blown resistors in the glow circuit step down

- fused wires leading to and from the glow relays

- dirty connections between the bus bar sections

- broken insulators allowing the circuit to ground out


~John

 

[daviesl]

my bad

my bad, sorry about that, that was a photo pulled off mud of a similar system just to illustrate the type I have, mine does have the connection between the power and the bus, i never noticed that in the thread. So, I put a volt meter to the glow plug relay under the hood, the square one, first between the two thin wires and turned the key, got power, then I put the ohm meter between the thick wires coming out and got positive connection reading, meaning that relay works. I then put the volt meter between the thin wires going to the round relay beneath the hood, I got power then it started 'counting down' for about 40 seconds by .1 volt increments till it reached 0 voltage. Then I undid the nuts that hold the two thick wires on the round relay, moved away the thick wires, and put the ohm meter across the bolts, turned the key, and momentary connection, like a split second then no connection. I get no voltage at all between the first power post of the bus and neg when I turn the key. Shouldn't i get something as the glow relay is working? I can't see the wires between the glow relay and the bus being bad?

 

[daviesl]

john

thanks for your quick reply john, sorry about leading you off base there with that photo, I've been meaning to head up to duncan to check you guys out, was planning on this week but looks like I'll have to wait, maybe my cruiser is afraid of the dentist

 

[daviesl]

superglow relay or timer?

ok, so the glow plug relay works, I get power to the bus from it, but the superglow is the one that's not working properly. now, I hooked up the superglow relay, the round one under the hood, to the thin wires that activate the glow plug relay (with the thick wires disconnected) and the rely worked and stayed for the duration of the glow plug relay cycle, a minute or so. but it won't work on it's on circuit. the thin feed wires (- and +) that go to the superglow relay gives 12v for a second then decreases rapidly till it reaches zero volts, it's not enough to keep the relay activated. Is this a timer issue or a superglow relay issue? Is the timer supposed to provide 12.7 volts (battery voltage) for a cycle to keep the relay open? I will obviously have to put a manual switch on the superglow relay till I figure this out. More reading on the timer circuit obviously.
Can someone disconnect their superglow relay and put a volt meter across the neg and pos leads that feed it, turn the key and record + tell me what voltage they get and for how long? Please.
Thank you.

 

[Radd Cruisers]

The main glow relay will be set to time for only a few seconds - perhaps 5 or 6 s in the temps we're having right now. If you cycle the key more than once, the primary glow relay may not activate again as they timer prevents glow plug burn out by cutting power to this relay. The secondary glow relay will cycle, however, when the key is turned on more than once in quick succession.

Make sure you have the correct glow plugs in there. The ones for a 12V superglow (BJ60) are supposed to be 6V plugs. Glow test each glow plug by removing it and hooking it up to 12V source - they should glow towards or right at the tip and each glow plug should light in about the same number of seconds.

~John

 

[daviesl]

thanks, I will try testing the plugs. They are 6v. I am putting in a wilson switch tomorrow for the superglow relay.

 

[daviesl]

right on

ok, after doing the wilson swiich (using the positive black and red line that feeds the glow plug relay to also feed the superglow relay via a normally open switch) I still couldn't start it, then I realized that I'd also replaced the fuel filter while trouble shooting and hadn't bleed the lines properly. Did that and now it's working just fine. thanks for the suggestions John.