Look at this pic......what is it and what is my truck missing.......

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shinkle

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I'm still learning about these old trucks.....It looks like mine is missing some sort of relay on the left bracket near the passenger firewall.

Also what should the red wire hanging loose be connected to?

1987 R10 5.7l TBI

Thanks all.

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RoryH19

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I'm still learning about these old trucks.....It looks like mine is missing some sort of relay on the left bracket near the passenger firewall.

Also what should the red wire hanging loose be connected to?

1987 R10 5.7l TBI

Thanks all.

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It's for the fuel injection, my 87 has the same only one.
 

gmbellew

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fuel pump relay
 

akchevrolet

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does that plug go to anything ive been wondering the same thing for mine haha
 

shinkle

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fuel pump relay

Am I missing a fuel pump relay? Wondering if it has anything to do with my passenger side tank not working.
 

bucket

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Most trucks don't have a second relay there. I don't remember off hand what would go there, if equipped.

The red wire is just a diagnostic hookup. Applying 12v there will energize the fuel pump.
 

jetmech

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The other bracket is for an identical relay that serves as a kickdown for TH-400 transmission. I have only seen this type of kickdown on computer controlled (TBI) trucks.
 

Craig 85

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I pulled this photo from a members 88-89 454 Suburban a few years back. It could be for the TH-400 or the factory aux fan relay. I added the aux fan to my K30, but in '85 this is the correct location.

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akchevrolet

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I also have 2 relays there on my 87 hmmmm
 

gmbellew

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I have 1 relay there on my 90 350tbi suburban. it is the fuel pump relay.
 

Jawzjeep

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91 sub with 700r4. Just agreeing. Only 1 relay. (Picture).

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My camaro I just sold had the same bracket that would hold two relays. They look like the same relays connection style and everything. On the Camaro there was two relays. One was for the fuel pump and the other was for the electric fans.
 

AuroraGirl

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If the vehicle was something like a big gm sedan, most likely a large rwd one in the dwindling days of the 80s, I could see a car maybe utilizing one of the relay spots for a WOT cutoff relay since that feature was becoming more common but this isn’t a very high likelihood, just an idea. The lockdown ajd fan experienced by others here make sense. I’d be curious if diesel trucks or cars of the time had the same bracket and if so what they held
 

Octane

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Most trucks don't have a second relay there. I don't remember off hand what would go there, if equipped.

The red wire is just a diagnostic hookup. Applying 12v there will energize the fuel pump.
I checked for a bad pump on my 90 chevy by turning the key on and putting a piece of hose into filler neck with other end put to my ear,I could hear pump running but I sure got a funny look from a passerby.lol
 

Raider L

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@Jawzjeep,

I see a little wire hanging from your relay to. What's it for? Is it like @bucket said, it's a test hookup? And TH400 in a TBI setup is for a kickdown relay?? That's weird.
 

Jawzjeep

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@Jawzjeep,

I see a little wire hanging from your relay to. What's it for? Is it like @bucket said, it's a test hookup? And TH400 in a TBI setup is for a kickdown relay?? That's weird.

I can't speak for the kick down relay. Somebody else will have to. I just snapped a pic of the bracket since it only had 1 relay on mine.

I dont know what the wire is for. If bucket said its a test hookup it probably is. Ive never tried it.
 

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