Fuel Pump Relay

[86MaximusPrime]

How can i tell if my fuel pump relay is bad...and where can i get a new one if that is the case?

Thanks.

86 Vmax

 

[MaxMidnight]

The easiest way to check is by substituting it with a known OK relay.

If that isn't available, then set your meter to 20V and connect the + ve to the blue/ black wire (keep this connected) and the black wire. Start the motor, you should see battery voltage which is output to the pump. If you get the correct reading check the wiring between relay & pump.
If no reading, the do the same check between the red/ white wire & black to check input voltage to the relay. If no voltage present check the red/white wire for damage.
If OK check the black (earth) wire for integrity.

If all OK then you will need to check the reserve switch circuit, the # 1 cylinder coil circuit and fuel level sensor.


If you suspect the pump take the pipe that feeds the carbs off and see what comes out when you turn the ignition on and turn the motor over.
Without wishing to state the obvious, you will need to be careful as you are potentially spraying fuel around - extending the pipe to discharge into a small necked container would be prudent.
If you are getting a good flow then it isn't the pump that is the issue.

If it doesn't run then disconnect the pump and check the windings resistance which should be between 1 & 10 ohms. You could also connect the pump to a battery which will eliminate non running due to problems elsewhere.

 

[86MaximusPrime]

THat is some really good advice, i will work on that today..the first thing im going to do is test the pump as far as getting fuel to the carbs then i will test the relay...now when you say check so and so wires...where exactly is this?

 

[MaxMidnight]

Methinks a wiring diagram would be of help?

 

[wildweasel_pt]

Here ya go... Now go work it out... :biglaugh:

 

[86MaximusPrime]

Here ya go... Now go work it out... :biglaugh:

haha thanks a bunch! a friend is comin over to give me a hand as well.

 

[Miles Long]

Re: Fuel Pump Relay-wiring diagram

Here ya go... Now go work it out... :biglaugh:

.....or go to the forum home page, click on the "Morley's Love Muscle" (I think that's what it's called) banner, go to the "how to" section, then "v-max wiring".
Here you will find (thanks to Sean),wiring diagrams for all years of the max. You will want the 85-89 diagram. All in living colour, very easy to follow!
Good luck!

 

[wildweasel_pt]

Re: Fuel Pump Relay-wiring diagram

.....or go to the forum home page, click on the "Morley's Love Muscle" (I think that's what it's called) banner, go to the "how to" section, then "v-max wiring".
Here you will find (thanks to Sean),wiring diagrams for all years of the max. You will want the 85-89 diagram. All in living colour, very easy to follow!
Good luck!

 

[wildweasel_pt]

He he... couldn't resist... :rofl_200::clapping:

 

[Miles Long]

He he... couldn't resist... :rofl_200::clapping:

You be one WILD son o' bitch, Mr. Weasel.........:biglaugh:

 

[wildweasel_pt]

You be one WILD son o' bitch, Mr. Weasel.........:biglaugh:

fftopic: :th_peace:

 

[one2dmax]

That is some funny shit!


Sean

 

[davesax36]

So I'm pretty sure my fuel pump relay is what's blowing my ignition fuse. I get power to all the wires except blue and black (which I'm pretty sure are the ones that run the pump). I can hear the pump click one time before the fuse blows. Not the usual pump working click, just that electrical "I'm gonna mess with your mind and make you think I'm working, but I'm secretly building up enough resistance to blow the last fuse you've got" click.

Sean's sending me an electrical test kit with some good parts in it, but is there something else I can try to make sure I don't just keep blowing fuses? The relay isn't cracked or anything, just dirty from sitting. All the other harness parts seem to be wrapped well and not worn or pulled in any funky ways either.