Hi everyone

I got all the parts and new wire to start the 'headlight relay upgrade'.
Where do you guys install the relays? (pictures if possible)

Sometimes my vette is driven in the rain (not by choice), and when it rains in Belgium, it pours. I don't think the relays like water?

 

Choose a place somewhere in the engine bay on the firewall that is high as possible to avoid splashes of water.....or choose a place in the engine bay near the top of the inner fender well.
Just make sure the under-side of the hood does not "smash" the relay when the hood is closed.
(I don't have pics...I haven't upgraded to relays yet)

 

I followed this.

 

This is where I put mine many years ago. Note that the connections point down. Water will run out this way, not fill up. Never a problem.

 

 

Same here.
On the fender well close to the alternator.

 

I used 3 relays as I like my regular low beams to be on a separate relay just in case something happens when all 4 high beam elements are on. Much more current load with the 4 high beams on than just low beams alone. It's just me being paranoid. LoL

 

I'm real sure a 30 amp relay will power all 4 high beams with no trouble whatsoever. plus a fair bit of extra wiring to add the additional relay. Paranoid, maybe.

 

YA but it wasn't that much more work.

 

Thank you all guys for the info!
Just one more question:
Where did you guys get power for the relays? Alternator?

 

I pulled it at the starter solenoid. (Battery positive cable.) through a fuse, up the firewall with the starter wiring, across the firewall, under the master cylinder and joined in with the headlight wiring running along the left inner fender.

 

I can understand why you would want a 3rd relay for the 4 element high beam side.
Sure a 30 amp relay will carry the load...
I know on a 1977 at the firewall bulkhead connector engine side there are 2 high beam Lt.GRN wires.
1 Lt.GRN wire is feeding left side 1 Lt.GRN wire feeding right side.
If you used the original wiring to the headlights one Lt.GRN wire feeding all 4 elements would have exceeded the amp rating for a #16 gauge wire.
Using the original wiring on a 2 relay install you will want to at least make sure you double wires out on pin 87 of the high relay so one Lt.GRN wire feeds left side, and 1 Lt.GRN wire feeds right side.
Here is a system I did for a buddy, he wanted duel element wired to inside lamps.
Used all original #16 gauge wiring, made a pigtail so relays could be bypassed back to original harness if needed.
Did not use that style fuse block shown in photo in his truck but did use fuse link.

 

If you wanna do your own relay set up-

Bosch 332019150 RockAuto has them for less $2- made in Portugal- not Chinah

https://www.rockauto.com/en/parts/bo...ing+relay,3380

It is a 5pin relay- but it has TWO output terminals-
Makes wiring soooo much easier.
I'm running 12GA- but have 80/100 and 100W High

I'd prefer to pull the power from the starter- a lot of the upgrades C3ers are adding fans- so doing a combo terminal block for the fans and headlights makes sense.

When you are uses fuses or circuit breakers for the headlights - The size is to protect the wire- it should blow/break before the wire melts- see the chart for what size fuse w/ gauge of wire-not problem going with a smaller amperage fuse but not vise versa.

My thoughts- $.02
Fusing will work if you have say high and low or left and right lights fused separately - that way when a fuse blows you still have some light -Do carry a few extras in the car makes AND sure the fuse is easily replaced in the dark.
I like LED fuses- light up when they are blown.

OEM uses a circuit breaker- which supposedly will reset when the current draw drops- like switching to low beam versus high. You do have the possibility of no lights - but you won't have to open the hood to fix.

So both ways have their pluses and minuses.

I'm running and electric headlight conversion- so where the actuator was- is a great place for the relay- easy to access AND right near the headlamps.







Here's a clean way to use three relays- each headlight has its own terminal- simplifies wiring

 

Has any body used this relay

GM Headlight Voltage Upgrade Kit | eBay

 

What if I took power from the alternator? Would that give me any problems?

 

I mount all my relays inside the RH fenders. I take power from the starter.
also, another Belgian corvette! Makes 3 people on here who are Belgian ( that I know of)