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Headlight Relay Harness

‘89Jimmy

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I purchased the headlight relay harness for my 89 Jimmy, but it appears to use different plugs. Also worth noting… I’m planning a grill swap to the earlier 85 to 87 style.

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From other pics you've posted, you have the quad 150mm headlights (the more common configuration for 89-91). That uses 4 smaller 2-pin connectors. If you are going to the earlier front end, that kit you have may work for that.
 
I thought I had included a 3rd photo that supports exactly what you said. Got it this time! Seems the older version is a H4 bulb style connector, which is what the new relay harness is. How hard would it be to convert the truck over? Has anyone here tried that?

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I believe you can get the front headlight/parking/turn signal harness unbolted and unplugged from the firewall junction box and replace it with a harness (junkyard) to match the grill/core support you have planned. I took that route with my ‘82 to update to the 85-87 style grill.
 
I converted an LMC relay harness from the 89-91 quad light style, that uses plugs that don’t match the OEM bulbs but their own 150mm composite housings. Which is a not so sneaky way of getting you to buy 4 housings for stupid money through LMC. I called BS on that nonsense and modified the harness to work with the two bulb setup from the cheaper Cheyanne grill that used the h4 sockets.

Picked up a couple of h4 pigtails and wired them in, though when going from two bulbs per side to one per side you will be adding both high and low circuits to the h4 socket.


Pretty straight forward. In hindsight I should have just bought the correct relay harness for a two bulb system and it would have been plug and play. But since I already had the harness and did not want give LMC any more money than necessary I modified what I had.

If the earlier setup you plan on running is a 4 light system it’s just a matter of changing the plugs out. For the two light system you do the same thing I did.
 

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