as the title asks , all they all the same ? after some elect. repairs i started to wonder . i noticed different #'s on the ones on my car . they all have the same elect. diagram on top . i then checked my parts CD and found G.M. has different part #'s for them depending on use . does anyone know ??? just a curious old man . thank's & good luck .

 

All relays are not the same. Some are high current relays and some a low current relays. Probably some other differences in them too like a resistor or diode inside them. A relay that controls the cooling fan or starter would most likely be different than the one that controls the vats system or rear defogger. You should always replace a relay for one thats rated the same or has the same part#. Thats why relays have different part#'s. If you use the wrong relay, you can burn up the relay or damage the system it controls.

 

thanks , that's what i figured . but , not really sure . thought i had a bad one for my a/c blower motor . thanks & good luck .

 

All of them in your engine bay on the 91 interchange freely

 

On an 89 5.7 TPI are the dual cooling fan relays the same.

 

From left to to right what are these 3 relays?

 

ive got same question lol ....so bump!

 

Arrangement means absolutely nothing. Check the wires and get back to us

Some years have the fuel, MAF, burnoff near the booster and the fans near the pass headlight. Others have fuel, fans, AC near the booster and nothing near the pass head light. Some years move the AC relay to the HVAC box

 

From left to right from the previous picture.

Square Relay (Fuel Pump Relay I think)

Tan/White
Black/White
Green/White
Red
Large Orange

Oval Relay (Don`t Know)

Orange
Black/White
Red
Tan/White
Dark Blue

Oval Relay ( Don`t Know)

Orange
Orange
Black
Dark Blue

On my car it has 2 relays behind pass headlight I`m pretty sure those are for the twin cooling fans. Are those relays the same part number? Mine are. Is that correct?
There also a single relay in front of the heater box/fan..

 

Fuel, MAF, burnoff respectively

http://www.austinthirdgen.org/mkport...ine_wiring.gif

MAF and burnoff relays have a built in resistor and are not interchangeable with the rest of your relays (fit fine, function is not)

Fuel, fans, AC, blower fan relays all interchange as long as the body is the same

 

Need help to properly ID my relays.. Here is my story...
Bought an 89 T/A that came from factory with a 5.7 auto the car had the TPI set up gone. Found a wrecked 90 Iroc on craigslist that I drove home with rebuilt 5.7 and trans that also had the TPI from factory. Transplanted the engine and trans in the mist of trouble shooting the start up on the 89 T/A with now the 90 Iroc engine and trans (changed out the knock sensor on the 90 engine to an 89 knock sensor as they are different the 90 iroc came with the map set up while the 89 comes with the mass set up)I swap out my relays thinking they were all the same. On my 89 the relays next to the brake booster the fuel is square while the other 2 relays Map power and the burn off are oval shape.
Here is what I have swap around a few times and I don`t know which is which any more.
My 89 T/A has a total of 5 oval relays under the hood. 2 behind the pass side headlight 1 near the heater box and the other 2 next to the brake booster.
I know for a fact that the two behind the passenger headlight which are oval are the factory ones which i have not mess with. There part numbers are
8280-14089936.

I have 5 oval relays that i have swap around and I need to properly id.
2 that came from the 90 Iroc engine harness and 3 from the 89 T/A (2 near the brake booster and 1 near the heater box).

8280-14089936
9256-14089936
9263-14103304
8277-14103304
1 with no part number at all ..

As you can see that the first 4 numbers change on both of these set and theres obviously a reason why GM did this.
I have checked the major on line parts suppliers such as Advance,AutoZone and RockAuto but they just have the basic 8 digits with out the first 4 digits.

 

take some to figuring witch is witch for mine, any good websites to check or purchase them all? I'm working out bugs on my iroc and posted my first thread the today, safe driving everyone

 

it is best to call your local chevy dealer, and ask for the GM part numbers of the relays. that way you can be sure to get the correct ones from your favorite parts store. problem solved.