Glow plug switch
Postmaster
Joined: Apr 2008
Posts: 4,802
Likes: 1
Bottom right corner of the dashboard, in a black-face panel, that's where your WTS/glowplugs light should be, along with two others IIRC. As to how to wire a switch - without knowing what condition your system is, I'd suggest the safest way would be to disconnect the thin wires from the glowplugs relay on the passenger-side inner fender, then identify which one is the trigger one and which one is the ground, then connect the ground one back on, and run a wire from the terminal where the trigger used to go to the switch inside the cab, then run a wire from the switch to a key-on location in your fuse panel. This is what we did with my buddy's '86 F250, only because we used slow-glow AC Delco plugs that require to be left on for quite some time we also upgraded the stock relay to a much heavier-duty GM unit designed for said slow-glow system.
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 16
From: Nutter Fort, WV
The only thing wrong in that picture is the wait to start wire is black with a pink stripe.
Small terminals are the ground and trigger wires.
Usually the ground wire is the one closest to the fender.
The trigger wire is usually closest to the engine.
If you draw power from a fuse that is only hot when the key is on, kids (large and small ones alike) can not turn the glow plugs on when the key is not on.
May save you from burnt out glow plugs or a dead battery.
Small terminals are the ground and trigger wires.
Usually the ground wire is the one closest to the fender.
The trigger wire is usually closest to the engine.
If you draw power from a fuse that is only hot when the key is on, kids (large and small ones alike) can not turn the glow plugs on when the key is not on.
May save you from burnt out glow plugs or a dead battery.
Junior User
Joined: Mar 2006
Posts: 62
Likes: 0
Beru plugs are the way to go. And if you bypass the controller you will want to install a push button switch. Glow plugs are only supposed to be on for about 12 to 15 seconds before you start the motor.
Trending Topics
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 16
From: Nutter Fort, WV
At 10 seconds glow time my engine starts just fine down to 0.
When it goes below zero, 10 seconds starts it and a second after glow of a few seconds keeps it running.
When it goes below zero, 10 seconds starts it and a second after glow of a few seconds keeps it running.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Postmaster
Joined: Apr 2008
Posts: 4,802
Likes: 1
The ones you're thinking of are the AC Delco glowplugs for a '79 Olds 350 diesel, they are a direct bolt-in for our engines. They also have spade connectors, so they will plug in the harness as well. However, you will not need those plugs if you go with the momentary-on switch and keep the duty cycle to 10 seconds or less, so just install that and a set of Beru plugs and call it good.
Postmaster
Joined: Mar 2008
Posts: 3,255
Likes: 0
From: Sweet Home, OR
That's what I did to my '86. Electric Golf Cart solenoid and 8 new Beru/Motorcraft glow plug and that hard starting B***H will start every time now.
I connected the glow plug wires off of the timer at the back of the motor together, passenger's side rear of timer moved over to driver's side front so they are directly connected.
Push button momentary switch with 3 amp in-line fuse wired to passengers side "small" post on timer. It's a "key on" power source.
Golf cart solenoid wired in to replace non-functioning factory one.
This motor WOULD NOT START unless it was 100 deg. or the block heater was plugged in. Like I said; now it fires up well.
One of these days I'll remove the timer completely as I don't like extraneous crap on my rigs for no reason. I wish every PO of every truck I've owned in the past felt that way. I've pulled enough junk, useless, burnt, leads-to-nowhere wire out of trucks and cars to last me a lifetime.
I connected the glow plug wires off of the timer at the back of the motor together, passenger's side rear of timer moved over to driver's side front so they are directly connected.
Push button momentary switch with 3 amp in-line fuse wired to passengers side "small" post on timer. It's a "key on" power source.
Golf cart solenoid wired in to replace non-functioning factory one.
This motor WOULD NOT START unless it was 100 deg. or the block heater was plugged in. Like I said; now it fires up well.
One of these days I'll remove the timer completely as I don't like extraneous crap on my rigs for no reason. I wish every PO of every truck I've owned in the past felt that way. I've pulled enough junk, useless, burnt, leads-to-nowhere wire out of trucks and cars to last me a lifetime.
Thread
Thread Starter
Forum
Replies
Last Post
Garrett Killgore
Pre-Power Stroke Diesel (7.3L IDI & 6.9L)
1
Dec 1, 2016 05:07 PM