89-91 Parking Light Question

[Shawn]

Ditching my hacked harness for factory 89-91 headlight/parking light harness.

I spliced the new harness with my firewall harness and matched the colors correctly. Shouldn't the bulb on the left be on when parking lights are on? It only flashes with turns/hazards so bulb works. Its only single filament. I think I may need to move that wire to the parking light wire or is this normal? Markers on the fender light up with parking lights and flash with hazards.



schematic here:
https://ck5.com/forums/resources/89-91-blazer-jimmy-grille-swap.19/

 

[frankin5]

what year is yours Shawn. The 85 -88 light has a two element bulb like the tail light. 1 is the parking on low beam and the turn signal on the high beam. What you have will require you to move the low beam and a ground to the clear.

 

[Shawn]

what year is yours Shawn. The 85 -88 light has a two element bulb like the tail light. 1 is the parking on low beam and the turn signal on the high beam. What you have will require you to move the low beam and a ground to the clear.

I have an 87 quad headlight. I thought maybe I could move that small single filament bulb on the left to the parking light circuit so it just stays on with lights but won't flash. I can separate both sides of wires if I need to. Never mentioned it in that article.

 

[Shawn]

Also found this from someone else. Will need to look deeper into this and see if he is right. I will most likely be doing a relay on the heads so just need one signal for lows and one for high. Hopefully both stay on when highs are on.

quote-
Here is some information that anybody doing this swap in the future might appreciate. I find it's little details like this which seem to be missing anytime there is a write-up about a swap to an 89-91 nose:

My 85 4-light system had 4 wires on the driver side low-beam pigtail and 3 wires on the passenger side low-beam pigtail. Drivers had two tan, one green and one black. Passenger side had one tan, one green and one black (well actually two black but one was to the firewall grounds and all blacks go to ground anyway so it's a minor point). High beams have only two wires: green and black

My 90 4-light system had 3 wires on the driver low-beam: two tan and one black. Passenger side low-beam had 2 wires: tan and black. High beams were the same as the 85: one green and one black on each high beam pigtail.

What I found was it does make a difference which side the 90 low-beam pigtails are on. 3-wire on driver, 2-wire on passenger. Here's the wiring tip: do NOT connect the extra green wire that the 85 harness had on the low beams to anything on the low-beam 90 pigtails. Connect both tans on the driver side to both tans on the 90 pigtail. On the passenger side, connect the one tan to the one tan and the black to the black. Do not connect the extra green wire on the passenger side either. High beams wire up without issue. Once I did this, my lights worked correctly.

 

[6872xtc]

That little 194A bulb should only work with the park lights. The one on the fender is wired to the park and turn circuits. When the turn signal is on, it grounds through the park lights. So it flashes in sync. When the park lights are on, it grounds through the turn bulb. When both turn and park circuits are hot, the bulb goes out due to no ground path as it has both wires hot. This makes it flash opposite the front light.
The factory wiring avoids having the two lights in the front housing flash opposite of each other since they are side by side.
As far as the headlights, I made all 4 of mine come on with high beam and fed them power through relays to give maximum power. So my original wiring is only triggering the relays. So, I would have to check it out in person to help much. I believe that the '87 quad lights had a high beam element in the "low beam" headlights. So it changed elements for each function. The '90 doesn't have a dual filament in the low beam.

 

[Shawn]

Thanks! I need to do some 12v probing and wire tracing on the harness and see what's triggering what. I think I might wire up my headlight relays so they can both come on with high beams triggered. When I probed the heads they both come on as expected but I did not check if low beams go off with high beams on. Everything seems to work as expected matching color to color except for those 194a bulbs.

 

[Shawn]

Ok I'm an idiot. Both bulbs were bad. I assumed they were ok since the signal bulb was bleeding over with the hazards. They actually work with parking lights now after replacing bulbs. Splicing wire color to wire color works fine. My brights shut off the low beams so I will need to get a relay kit to prevent that.

 

[6872xtc]

Ok I'm an idiot. Both bulbs were bad. I assumed they were ok since the signal bulb was bleeding over with the hazards. They actually work with parking lights now after replacing bulbs. Splicing wire color to wire color works fine. My brights shut off the low beams so I will need to get a relay kit to prevent that.

Just love the reminders of being human sometimes... at least it was a small flub, right ?
I don't have any idea who makes the best headlight wiring kit for the money, but hopefully you can find decent wire and not have to re-loom it to have a nice look.

 

[Shawn]

Painless wiring makes a kit to keep all 4 lights on so I will look at that and others. A relay kit on most cars these days is a must to get the full 12v of battery as well.