I have an 84 and want to upgrade my headlight motors to later model. I have bought 89 headlight assemblies that are complete with wiring harnesses, housing and all. But I don't have the modules or relays these harnesses plug into. What do I need to get? Can I get the modules from a salvage yard off a different car? Any help would be much appreciated.

 

salvage yard would be cheapest, some of the venders sell kits.

 

Are there any how-to write-ups on this? I need a little more specific information on what wires from the 84 hook up to the relays of the later model and such. I ran a search on the forum and could find nothing on it. I found a module that looks like my plugs from the later model motors will hook up to. If this is the part I need, then I would like to know what wires my 84 do I use to hook everything up.

 

The later year lights dont have the relays. I dont have experience with the 84, I think mid america has a tech writeup for this, theres several posts about this , do a search for "headlight upgrade". there's three pages. a few have the wire diagram.

 

pontiac firebirds 88-02, and circa 1990 pontiac sunbirds WITH flip headlites, all used the same headlite motor control module as late c4's...the ponchos have a metal bracket lightly crimped around the module, ez remove...problem of age related failure of these modules is common...cheaper/more dependable/easier, imho, is to mimic mid-year vette manual headlite motor control using a new $5 DPDT toggle switch and a pair of auto circuit breakers from raddyshack.

 

any chance you'ld have a wire diagram for this?

 

Is there a module for each side or just one module that both headlights plug into?

 

one module for both, you locate it in the same spot as the old relays after you remove them. grab the two wire plugs for the light assemblies and about 8-10 inches of pigtail thats attached to them. when you hook up the new lites, the harness thats on your car already will work, you just wont use one of the wires. the same at the module/relay plugs. they may be colored different , but they do the same thing. there should be enough wires that match, that when you hook those up the others will make sence. hope this helps. I bought the wiring upgrade kit that one of the venders sells, it included plugs w/pigtails that I just spliced in. they didnt match on some of the colors and the wire diagram they sent didnt match either my car or the kit but as I said , theres enough wires that match , that the ones left will be obvious. the relay/module is critical, there are wire diagrams on this site in other posts, and a few of the venders have them on their tech section. I just looked at midamericas, search for 'headlight upgrade' on their site.

 

I was confused because when I look at the module, it looks like the two plug-ins are different. I have not held one in my hands, they just look like one plug would be bigger than the other and I was expecting them to be the same size. Maybe they are, I am not sure.

 

I guess the two wire plug from each headlight motor would plug into the module. Would that be correct?

 

the module plugs are different sizes, you need to get doner plugs , one of the module plugs goes to your cars power side and they replace the relays plugs, looking at pictures of the module wont do you any good, look at the wire diagram or find a doner car and label all the wires. a real good way to do it is to buy the kit from midamerica, it will have all the plugs a new module, and the diagram will keep you from frying your new lites. its bout 200 bucks but theyve done all the work and you get a new module

 

I'm sorry but that make no sense to me. I have the later model assemblies with the wiring plugs so why would the modules be different than than the plugs that I have? The modules I have been looking at say they fit 88-96 so why would the plugs be different?

 

look at the wire diagram

 

Is there anyone out there that has done this before have any more information on upgrading the headlights to a later model c4?

 

too simple to bother with a schematic...12v+(fused) and ground wires to DPDT (momentary, of curse) switch gives 'flip-flop' power/ground output to the headlite motors...each motor should have an automotive (auto reset) circuit breaker to shut off power when headlite is at full up/down travel (motor at LRA draws more current than running)...trash ALL the relays and 'black' boxes.

this is the same design as most power windows/seats/mirrors/etc use (could can those parts from 'j-y supply' but probly cost more there 'used' than raddyshack 'new')

btw, the vette/poncho headlite module 4-pin connector is 'output' to the headlite motors, a power and a ground wire for each lite motor....the 5-pin connector is 'inputs' from the headlite (dashboard) switch and 'fused' power and earth (two 'fused' power feeds, one 'go up' signal wire, one 'go down signal wire, one ground wire)...note that the vette/p headlite module does NOT limit current flow, only shuts down power when no 'ripple' is sensed at motor, hence external 'fuse' must protect the module/wiring/motor.

b4 u ask; the 'early' three-wire motors and be modded and used with the 'late' headlite module OR the raddyshack switch, by simply tying two of the three wires together, creating a 'two-wire' motor (C.R.S. due to 'senior status', not sure which two wires, check the SM schematic)...thus 'modded', the early 'relays nest' can not be used...'late' two-wire motors can not be modded for early 'relay nest' installs.

 

this is excellent, wish I'd seen this before i did mine. Printing and saving for future use, many thanks, respectfully, bob

 

your horsehoe that holds the assemblies is different also from the later year horseshoe's. just 'looked' at mid americas tech instructions again. you can 'look' at the pictures of the parts they have on the picture and see what you need. it will probably make more sense cause they are in relation to each other....in other words, where they're suposed to go.

 

YES! I finally found that thread for the tech. That is what I need. Thanks OldAlaskaman I do appreciate it and also thanks to redrose for your information as well.

Danny

 

excellent