Manual Glow Plog Switch

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SURVEYOR CRUISER

SURVEYOR CRUISER

10 Year 15 Year
Joined
Oct 23, 2006
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19
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So I have had my 85 Bj70 12 volt for several years and finally tore it apart to do some work. It had a manual glow plug switch so you could heat as long as desired. When i pulled the dash which is a pain, if found two wire going from the switch to the factory glow plug relay and a third wire which may have come disconnected from who knows where? I am guessing a 12 volt source I hope. Does anyone have this set up or suggestions. Putting it back together very soon.
Thanks
 
i went out this morning and checked the timer/primary relay with test light and voltmeter for proper operation. the voltage dropped aafter about 3 seconds , so i bypassed the relay by using 2 jumper wires from the battery to the primary relay i glowed the plugs about 20 seconds and it fired right away , now i am headed out to princess auto to get my switch and wires , thanks guys .
 
Here is some more info. The two wires from the switch go to the glow plug timer relay which under the dash on the passenger side and connect to the orange-black and red-black wires whcih go to the glow plug time relay. On my switch I have a third wire and am unsure where it goes if anywhere. Help would be appreciated. Also what do you mean by a "wilson switch"
thanks
 
i will asume the third wire was wired to the " glow light" on your dash , i have omited that and just watch my voltage , i bypassed my timer completley but left the option to re use it when and if i find another properly working timer by un pluging the harness and using splicing conectors , the red black wire sends current to the solenoid the yellow black or orange black wire is accesorie power that completes the circuit for the wilson switch , the 3rd wire likley sends power to the dash glow light .

by the way i was able to wire up in about ten minutes thanks to the excellent posts here , in contrast it took me an hour to go out and buy the switch and find my tools .

thanks to every one on this excellent web site . kevin .

https://forum.ih8mud.com/showthread.php?t=38416
 
I think the timers after 20 years are just scrap. No point saving them. The wilson switch that Greg_B describes is fully functional. It just takes two wire out of the timer harness and bypasses them thru a swith.

One note about the switch. Only use a push botton one that cannot be left on. Or you will forget it and damage could occur. They may get hot enough will driving to melt( I am guessing) and drop the tips into the engine.

Especially if you did not bother with a light.

I like the light and the push button. No rocker switches.

The push button one is like a starter switch on a tractor.
 
the best way to describe the switch to the parts guys at napa is to tell them you want a " momentary on " switch . go for the heavy duty switch mine was about 17 $ but i got it at crappy tire . oh and it worked like it was suposed to this morning least amount of smoke ive ever seen , fired right up after holding about 10 seconds .
 
Thank you so much for the info. One final question, the third wire, which I guess goes to the light on the dash, does this plug directly into the light on the back of the dash, or remotely elsewhere.
As per my switch it is a toggle which returns to the off position after being flipped on.

Question on Glow plugs: In the thread which Greg_B linked in it talks of two different types of glow plugs. I still have the sensor hooked up at the thermostat housing.

So is my preheat timer fully bypassed in that this set up is manual?
I did not install it and have not had to ever mess with it.

Thanks for the help guys:beer:
 
i'm not really sure whats going on, but on a lighted momentary switch you should have power in, power out and ground for the light to work. the light should not be in series with the rest of the sytem. the power going out from the switch should run to one of the smaller terminals on the relay. the other small terminal usually marked with a ground or minus symbol would go to ground. this part of the relay is an electromagnet the pulls the contacts in.
the larger terminals of the relay will have larger amperage wire depending on whats being used, one wire in and one wire out, because this is just a contact it shouldnt matter which side is which. the other large terminal will go to the load. i am not sure about any factory options or existing wiring but i hope this helps.
 
if the momentary switch only has to terminals and 3 wires off of it, one on the load side (not battery side) will go to the light and then from the light to ground. what that will do is: when the switch is pressed it will send power to the relay and to the light indicating the plugs are warming.
 
Not sure how long you may want to keep the power on the glowplugs. I have heard if you leave them on for too long you just shorten their life before they burn open which makes sense.

I like the idea on the 3B superglow system. It maintains 8.5 volts to the glowplugs for a while and then drops this to 4.5 volts for a while and then off.
 
So after months apart I am finally putting my 70 back together.
Everyone here has been of much help. As per my switch with two wires running from the switch to the two wires pulled off of my "timer, Pre-heater" as the label says ( this is under my dash behind the glove box). My light wiring has not been touched! The light worked when the glow plugs were switched on. I am thinking that this third wire must be a ground as the other two are most likely hot?
I am pretty sure that most toggle swithces or buttons have to have a ground to operate? Input is most appreciate as I dont want to fry anything. Thanks for the help:beer:
 
hi,
your switch could be like mine, a three-way toggle! i use mine on the superglow on my 85bj60. one side is for full power and the other is for half power. the middle is spring returned to off. :cheers:
hth,
 
Superglow????

So in response to the last post. I am guessing I must have the "superglow" set up where it tricks the preheater into switching the glow plugs on when the switch is on. For this set up is power required at the switch? Or is ground required at the switch. The two wires at the pre heat timer are already connected and the third wire hangs off of my switch is disconnected. My light has never been messed with Please help!!!
 
SURVEYOR CRUISER said:
So in response to the last post. I am guessing I must have the "superglow" set up where it tricks the preheater into switching the glow plugs on when the switch is on. For this set up is power required at the switch? Or is ground required at the switch. The two wires at the pre heat timer are already connected and the third wire hangs off of my switch is disconnected. My light has never been messed with Please help!!!
Click to expand...


you have the superglow system in your 85bj70. all you need is a switch to power-up your glowplug relays one at a time. that is why i have a three-way switch. in your case, nobody knows but my guess is you have a two-way switch like everyone else. i seem to be the only one with the choice of using the two relays. there is nothing wrong using only the primary relay. the switch doesn't need to be grounded. the extra wire is probably for the glowlight like someone else mentioned. do not ground it! i've tried using my light too but it never worked for me. my preheater timer is completely disconnected and i'm using the plug end of it only to tap my switch into it. one of the connection on the plug gives you 12v ignition power and finding the other for the relay is all you need to connect the momentarily switch. hope i'm explaining this clearly if not pm me.
hth,
 
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