1977 S frunck relays confirmation

[7783911]

I have 2 black and one red relay that I need to install
I believe RED is fuel pump
2 Blacks?

from back to front are 6 positions for relays

position 1 (nearest WS) should be RED for fuel Pump?
# 2 NOT IN USE
#3 Electric Windows (not in use)
# 4 Horn? - Black
# 5 Fog Lights? - Black
# 6 A/C

Is that correct? Whats the difference between RED and Black relays?

Thanks

Bob

[Ryce Stallings]

My parts guy says red and black are the same. He says the red was added to make it easy to find the fuel pump but who knows.

[HaroldMHedge]

The relays are not the same the red ones have a diode in them to prevent a backwards voltage spike when the coil field collapses.

[tmadden2]

Originally Posted by HaroldMHedge

The relays are not the same the red ones have a diode in them to prevent a backwards voltage spike when the coil field collapses.

The diode is why you can make them all red if you wanted to. That won't hurt anything. But going the other way and making them all black is not recommended.

[spuggy]

Yes, the red relays have a diode to minimise arcing/spikes.

But the stealer didn't have any in stock when I stopped by, so I ran the car 50,000 miles on CIS with a black relay on the fuel pump. The spare I bought in 2008 is still in the glove box (found it the other day).

[spuggy]

Originally Posted by 7783911

Is that correct?

Relay positions you posted look right to me; I forgot to pull the horn relay when I took the wheel off the other day - that is definitely #4...