I want to install a 789 Delco Remy Headlight Relay on my 39. It has a fuse holder with a terminal at each end of the fuse holder. Two other terminals coming off the side of the relay. I have no clue how to wire this up. Anyone have a wiring diagram for this unit? I believe the part number would be 1116789.
I believe a wire goes from the battery to the fuse holder terminal. One side terminal goes to the dimmer switch and the other goes to the headlights. Looks like I'll need 2 of these headlight relays, one for low beam and one for high beam.
I installed the headlight relay on the low beam/dim side of the circuit. Now the low beam/dim headlights are brighter than the high beam lights. Need to pick up another headlight relay switch!!!!!
Can someone please tell me the part # for the original Delco Remy headlight relay for a 1950 half ton? There are a few on eBay. I’d like to install a couple so I can drive safely at night.
Chuck 1950 Chevy 1/2 ton (all original) 1951 Chevy 1/2 ton (future streetrod) 1941 Chevy coupe 1938 Chevy coupe streetrod
My memory says they never used a relay for the headlamps. The headlight switch has a self resetting circuit breaker built in. Relays are user installed if you want to use a better sealed beam that will draw more power. Or a European lamp with a H4 bulb.
The relay you want is a basic 4 or 5 pin relay usually sold for less than 6/8 bucks. The 5 pin is a normally open or closed unit. A 4 pin is normally open and that is what will work. Put one in each circuit. One for low, one for high. Inexpensive and available every where. Your local autoparts store will have them. Or look under the hood of most European cars at the wrecker, They all have them.
I buy them a dozen at a time on Ebay- - - - -about $4.00 apiece. They're also available with a 6 volt coil. Most of them come with the multi-pin plug and wires included in the price. I'm upgrading my motorcycle headlight system with a relay-operated halogen headlight today, and a set of passing lights soon, also through a relay. That eliminates multiple switches with a little resistance in every contact, and the voltage from the dimmer switch is only used to power the coils on the relays. Less voltage drop- - - - -brighter lights! I run a fused, heavy wire from the battery bus to a convenient mounting place close to the headlights to mount the relays, which minimizes voltage loss before it gets to the end item. Either 4 or 5 pin relays work- - - - -just clip off the wire to the "normally closed" contact. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Jerry, please tell me what to look for on eBay. Do I simply search for “head light relay 6 volt” ? Is there a certain brand or model or shape I should buy? You have the experience I don’t have. Thanks.
Chuck 1950 Chevy 1/2 ton (all original) 1951 Chevy 1/2 ton (future streetrod) 1941 Chevy coupe 1938 Chevy coupe streetrod
There are dozens of similar auctions under the same heading, both 6 and 12 volt, with amperage capacities up to 60 or more. The basic 30 amp relay works for everything except possibly powering the pull-in winding on a GM starter solenoid.
OOPS! I missed the 6 volt part!
Here's a link: https://www.ebay.com/itm/TE-CONNECTIVITY-P-B-RELAY-1432873-1-SPDT-1-Form-C-6VDC-Coil-Chassis-Mount/232295092418?epid=1207671334&hash=item3615ddd0c2:g:AQ0AAOSwB-1Y5uAS:sc:USPSFirstClass!38453!US!-1
It doesn't come with a connector. Drop me a PM and I'll send you a couple of them. Here's a lin k to connectors that fit both 6 and 12 volt Bosch-type relays:
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Jerry, you amaze me! Is there anything you don’t know about cars?!? I am a self taught, amateur shade tree mechanic who learned basic automotive skills out of both interest and necessity. Mom and dad were good enough to buy me a car in high school, but it was up to me to keep it running. With mom and dad raising three kids, it took both of them working to make ends meet. There just wasn’t a lot of extra money, so anything I could do on the car myself was money saved. The one part of a car I never learned to work on was the electrical system, mostly out of fear. It was always this mysterious system that had too many bugaboos in it for me to figure it out, so I left it alone. Even today, about the most I can do is change a headlight or a battery. You helped me last fall tackle the job of upgrading the small gauge battery cables in my 6 volt truck to bigger ones. Thanks for helping me with these relays. I’m tired of not being able to see more than 15 feet in front of me when I drive at night!
Chuck 1950 Chevy 1/2 ton (all original) 1951 Chevy 1/2 ton (future streetrod) 1941 Chevy coupe 1938 Chevy coupe streetrod
I had the great good fortune to grow up around one of the best independent auto shops in Nashville Tennessee in the 1950's, the place where the car dealers in town sent the problem jobs their own mechanics couldn't fix. In the process, I got to hang out with a bunch of oldtimers who had worked on cars from the 1920's on up. They might have been a little rough around the edges and barely able to read and write, but they were willing to share their knowledge with a smart-donkey kid who could be downright annoying at times. Now it's my turn to be the old geezer with something to share! Spending a lot of years as an Air Force electronics technician and later as an industrial maintenance guy and a pipefitter and machinist sort of helped round out my degree from the school of hard knocks! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
If I were to install a two Bosch relay system on my '58 to solve the cut-out of headlights after 20 seconds on high beam: do I splice into the small lighter gauge wires that lead to the headlight bulbs from the "high-voltage" side of each relay that several sites recommend 12 ga wire? I ask, since I cannot find wire ends that will fit over the tabs on each headlight. If I could find the correct ends, I have no issue running the 12 gauge wire. Does anyone have a source for this size of wire end?
Just cut the 3-prong connectors off the headlight harness and splice two of the wires into the output terminals from the relays. The third wire is a ground. A couple of inches of small wire spliced to the 12 gauge won't make much difference. A plain old insulated flat blade female terminal will slide right onto the headlight male blade terminal if you don't want to mess with doing any splicing. In the past two weeks I've wired both my motorcycles for high output halogen bulb headlights, using Bosch relays and 12 gauge wire. They really light up the night! I've also got 55 watt LED side lights on both bikes. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Here's a wiring schematic for a standard Bosch relay. You'd need one relay for high beams and one for low beams.
The source for the control wiring can come off the dimmer switch to terminal 85 of the relay.
I've done this on my SuperDuty to eliminate the voltage drop from the battery, up thru the multifunction switch, and back to the lights. Ford uses wires that are really too skinny for the load and you wind up with the power heating up the wiring instead of lighting up the road.
Last edited by klhansen; 08/25/20186:33 AM. Reason: fixed oops on terminal number.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
On just about any new circuit or rewiring job, I use one wire gauge larger than what's recommended for the accessory. Material cost is a one-time expense- - - -voltage drop is forever! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I really want to run the 12 gauge all the way from the relays to the headlights. The tabs on my headlights (GE H5006) are 5/16 (7.93mm) wide. I looked at and called every place around town today to find quick connects to fit the bulbs, with no success. Plenty of .250" wide terminals and smaller size. No place had the .25" that were for 12 gauge, but found they can be ordered from Advance Auto. I am looking at taking Dremel tool and grinding down (gently! Not wild about grinding down the spades!) each male spade or buying some over priced .3125 wide terminals from Newark or Del City..... These would be non-insulated terminals. The good part is that these will fit the 12 gauge wire and I can get heat shrink that will fit over the terminals and the wire. I am open for suggestions to find the terminals with the .3125 width.
Just solder the wires to the headlight bulb prongs, or grind them a little. Shrink tubing over the connectors is a good idea, no matter how you choose to attach the wires. I think I'd strip the 12 gauge back about an inch, make 3 or 4 wraps around the light terminal, and get out the old soldering iron- - - -MUCH better, lower resistance connections than any kind of spade terminal will give you! Just remember to slide a piece of shrink tubing up on the wire before you start soldering! Using real rosin core 60%-40% tin/lead solder is a good idea, also. That lead-free stuff sucks like a Dyson vacuum cleaner! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I was the original poster. I installed a 1116789 headlight relay to my 6V headlights, dim side. Now my dims are brighter than the bright lights. Need to find another 1116789 relay for the brights.
The Bosch-type relays are available with 6 volt coils for about $5.00 apiece. Unless you're building a show car with OEM parts, paying those kinds of prices is foolish!
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Forgive my stupid questions: - are they wired-in "before" or "after" the Headlamp Terminal Blocks on each inner fender? - one relay or two or three/four relays for front lights on an A-D truck? - one relay for headlamps and one front parking lamps; and/or, one (each) for both sides? - do people use them for 6v rear lamp/lamps?
I'll try cleaning grounding screws/bolt-points, and maybe then try grounding wires; but, after that . . . .
I wired one terminal of the relay directly to the 6v battery and another terminal to the wire going to the headlights, dim circuit. When I turn on the headlights using the headlight switch the original circuit becomes live down to the dimmer switch. From the dimmer switch the wire goes to the relay switch, activating it and letting the 6v coming directly from the battery to go directly to the dim side of the headlights. Now, I need to install another one from the bright side of the dimmer switch to the headlights.
It takes two relays to get high and low beam. Rick has it right- - - -run a heavy wire from a good battery voltage source like the starter cable terminal to somewhere on the core support near the headlights, and wire it to both relays- - - -terminal #30. Wire terminal #87 of one relay to both high beam filaments of the headlights. Wire the high beam output of the dimmer switch to terminal #85. Wire terminal #86 to a good ground.
Low beams- - - -connect terminal #30 of another relay to the heavy wire from the starter cable. Wire terminal #87 to both low beam headlight connectors. Wire the low beam wire from the dimmer switch to terminal #85. Ground terminal #86. Now all you need to finish the job is a heavy wire connected to the ground terminal of both headlights to a good ground such as the frame or the body, or even back to the grounded battery cable. Use at least #12 wire for all the power and ground connections for the sealed beams. Smaller wire can be used from the dimmer switch to the relays, since the dimmer and the headlight switch will only be carrying a couple of amps of current to energize the relays. All the heavy current is carried by the big wires to and from the relay contacts. The same terminal numbers are used on both 6 and 12 volt relays.
The park and tail light circuits from the light switch will remain unchanged. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
The only difference when I did it on my Superduty was I installed a fuse between the hot terminal I used as a source to both the high and low relays. I wired the control wiring to the original headlight plug, soldering the wires to the filament holder wires of an burnt out bulb and plugged that into the headlight plug. If I ever wanted to, I could go back to the stock wiring (but why???) simply by unplugging the relay harnesses and reconnecting the headlight plugs back to the bulbs. I also soldered a diode into another old bulb and plugged that into the unused socket so that in high beam, the low beam relay was also activated (both filaments on at once).
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
