Hot Rod Forum banner

Ford relay ratings?

16K views 16 replies 5 participants last post by  oldred 
#1 ·
Anyone know the Amp rating on Ford fuel pump relays? How about the other similar relays such as the EEC power relay or the WOT cutout relay?
 
#2 ·
Doc here, :pimp:

That's something you will have to look up Vehicle specific, displacement specific, and application Specific....

Not all "Ford" relays are the same..they vary from application to application..

Most automotive relays range from 30 amp on up to heavy current handling relays..in increments of 10 amps..If you had to guestimate..go with a 40..unlike fuses, too big is better..

The other way to tell, is pull the relay, look on the bottom or side of the relay for a data plate that looks like this:
  • Coil: 12 VDC

  • Coil Draw: 1 amp.

  • Contact rating: 250 VAC/DC (Arc over or weld point)

  • Contact Current Max: 30 amp. (melt down point)


Or it may have one of hose Day~um cryptic Ford numbers like : CAE~0006724~8946234~268947`30 :sweat: , That you need an Enigma Machine , Code breakers at Heathrow, and the French underground sending coded messages to "Kinch" at stalag 13 , to relay to Hogan to Decipher :mad: ...to cross it over to an item we humans can deal with.. :thumbup:

Doc :pimp:
 
#4 ·
Doc here, :pimp:

You may want to Try this:

Get a Bosch relay, 40 amp...(Kragens has them for like $3.99 just bring yours in for matching)..

and compare the footprint against the footprint of the relay that came out..

If they match, go ahead and try it..It should work, as the Items you listed SHOULD not draw more than 40 amp..AND going larger on a relay won't compromise anything..

If the footprint doesn't match, try a bosch in Single pole, single throw,..Double throw, Double row, etc..(different contact arrangements and pin counts) until you find a match.

Standard Pin arrangements for a Bosch relay are:
  • Pin#85 = Coil + or - 12VDC, about 1 amp.

  • Pin#86 = Coil + or - 12VDC, about 1 amp.

  • Pin#30 = Center wiper CONTACT SET.

  • Pin#87 = Normally Open CONTACT SET.

  • Pin#87a = Normally Closed CONTACT SET.




You can OHM this out (while powering the coil) to verify this arrangement.



That should help.

Doc :pimp:
 
#6 · (Edited)
1987 Mustang LX 5.0

One is a fuel pump relay-E3TB-9345-A2A

The other is a EEC power relay-E3AF-12A646-B2A

Another nearly identical EEC power relay I have has almost the same number and fits the socket-E3(A?)12A646-B1A/7ED

Unknown application Ford relay-E4LB-13A025-A2A

I am assuming that is one part number for each but it is arranged in three numbers (hence the dashes) vertically on the case, for space reasons I assume.
 
#7 ·
oldred said:
1987 Mustang LX 5.0

One is a fuel pump relay-E3TB-9345-A2A

The other is a EEC power relay-E3AF-12A646-B2A

Another nearly identical EEC power relay I have has almost the same number and fits the socket-E3(A?)12A646-B1A/7ED

Unknown application Ford relay-E4LB-13A025-A2A

I am assuming that is one part number for each but it is arranged in three numbers (hence the dashes) vertically on the case, for space reasons I assume.
Red,

Sorry it took so long...Milk of Magnesia took a while to cut in this morning... :pain:

The FORD MPC has a master Relay I.D. Changeover but does not give the AMP ratings. If the relay is not actually marked regarding it's rating, you will have to go to a wiring diagram. Thought I could cheat but no.

The E4LB 13A024-A2A is a LINC headlamp dimmer relay.
 
#11 ·
Doc here, :pimp:

To find out what is required as to draw on any certain relay, go to the Device it supports ... read the data plate and see what the draw is..THEN note the gauge wire, compare that and the length of the run against a National AWG chart..

Do not use a relay LOWER in value than the device or wire gauge..

The SAME info may be present at the fuse panel, at the device fuse..

I'm betting for what you are needing, any 30 amp relays with a matching footprint will work just fine..

Only when you get up into cooling fans and the like do your relays go high current due to startup and spike conditions as well as wind resistance and rotor lock.

Headlight circuits use higher current relays as well.


Doc :pimp:
 
#14 · (Edited)
I went to NapaOnLine.com and entered those Ford engineering numbers into the [Non-Napa Part Number] field and pressed [Go] ...
These are the results.



# E3TB 9345 A2A -- Fuel Pump Relay
Napa Echlin Part Number: AR-240

Attributes:
Features & Benefits:N.O. Terminals 3-4 @ 35 Amps; N.C. Terminals 3-5 @ 20 Amps; Coil Terminals 1-2
# of Terminals:5

----------------------------------



# E3AF-12A646-B2A -- EEC Power Relay
NAPA Echlin Part Number: AR-242

Attributes:
Features & Benefits:N.O. Terminals 3-4 @ 25 Amps; N.C. Terminals 3-5 @ 15 Amps; Coil Terminals 1-2
# of Terminals:5

----------------------------------

Just for fun ... I also went to www.Motorcraft.com (Ford's own) and tried to c/ref them there ... and no go!

I used to sell a ton of both of these relays, and used to know the Motorcraft numbers off the top of my head ... but that's gone now. :embarrass

These relays are used for a multitude of different applications and functions.
For example, 87-91 F-Series pickups used one of each side-by-side under the hood for fuel pump/EEC purposes as well.

Edit / Add-on:
Regarding the suffix on those Ford engineering numbers (-A1A, -A2A ... etc)
The DIGIT (1,2) an usually be ignored. It usually indicates a minor revision or a supplier change. In other words ... E3TB-9345-AA is the same as "E3TB-9345-A1A and A2A".
 
#15 ·
Thanks, I have added all this to my reference book :) I had noticed that suffix difference on two apparently otherwise identical fuel pump relays and I was curious about what could be different. What brought all this up is that I switched to a Bosch external fuel pump from the Mustang in-tank pump I had been using. I have not yet checked the current draw on this new pump but the thing is huge compared to the Ford in-tank pump and I was afraid the stock relay would not be heavy enough. The question about a relay for an auxiliary fuse panel is for another project and the fuel pump was my big concern here. I was told by someone local that the EEC power relay was rated higher than the fuel pump relay but I was a bit skeptical that was the case and apparently it is the other way around.
Thanks again everyone.
 
#16 ·
oldred said:
The question about a relay for an auxiliary fuse panel is for another project and the fuel pump was my big concern here. I was told by someone local that the EEC power relay was rated higher than the fuel pump relay but I was a bit skeptical that was the case and apparently it is the other way around.
Thanks again everyone.
Doc here, :pimp:

For ANY AUX type fuse panel, you really want a continues Duty SOLENOID..not a relay..

Where the contacts are rated in 100's of amps not in amps..

There ar several good type Marine or Electric Forklift type solenoids around to serve this purpose in Continuous operation...a Ford type solenoid WILL NOT work..it will overheat and fail.


Also , on ANY relay, PROVIDED, it has the same pin count/operation, (NC, NO, CW) but the pins won't fit a stock type relay socket, you can build a "Gender Bender " to a Bosch Standard relay (That you can get anywhere for $4.00), simply by using the provided Relay SOCKET, (for the Bosch) and after confirming the pin operations on both, using a Bandsaw OR Sawzall, carefully cut and REMOVE the plastic cover off the relay, (Stock relay) about 1 ~ 1/4 inches UP from the base of the relay, and just IN enough to separate the PLASTIC..Don't cut the relay.

To be sure of Function follow the contact and coil wires out by sight, make a note , such as : Pin 1 = Coil (Ford) Pin 85 = Coil (Bosch) , Pin 3 = Center wiper (Ford Relay) Pin 30 = Center wiper (Bosch) .. and so on..

Then remove the mechanical relay from the bottom of the relay socket (unsolder) and using the proper gauge wire, and your notes, wire the two "sockets" together..The Bottom (Male pins) will mate to a Ford Harness, the top (Female socket) will accept any Bosch standard relay.

You can cover it in LARGE heat shrink tube, Or fancy it up and epoxy it between the sockets in a jig so it looks just like a relay ..or just tape the center up..(the easy way..)

Doc :pimp:
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top