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> relay board
lonnie152
post Apr 28 2008, 04:37 PM
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problematic relay board - can not get power for fuel pump from side of board to the other. did search and note some have stripped and rebuilt them. so does anyone:
1. have an inexpensive rebuilt option;
2. know of a service or shop that does this;
3. have a fix to simply wire around problem?

thanks in advance for any help.
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hcdmueller
post Apr 28 2008, 04:45 PM
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Mine still works but the bottom black sealing material is dry and coming off. It is only a matter of time before something goes wrong with mine. I look forward to an answer to these questions.
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dr914@autoatlanta.com
post Apr 28 2008, 04:52 PM
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Sean here redoes them and can answer any questions you may have 770 427 2844 ext 27
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swl
post Apr 28 2008, 05:30 PM
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have you done any trouble shooting yet? A bit of poking around with a voltmeter can often time locate the problem. Probabilities are pretty good that it is not the PCB. The relays or the fuse/fuse holder are the common culprits. If you need some help I'd be happy to step you through it.
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type47
post Apr 28 2008, 07:16 PM
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get a picture of the current paths in the relay board (look on pelican electrical diagrams or workshop manual) and do continuity checks between terminals. i had a fuel pump delevery issue and determined it was not the relay board but the pump (it could have been that the pump was OK but the board bad)
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Chris Pincetich
post Apr 28 2008, 11:09 PM
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The Haynes Manual has lots of good relay board diagrams covering all 914 years. Repairs can be made on the underside with new soldiered wire, but be careful getting all that gunk off the back. Some racers wire the fuel pump seperately, some cars use the extra switch as an anti-theft mechanism. Jumping it is OK for diagnostics, but make sure the fix is roadworthy. I ended up having a bad voltage regulator from rust and the rest was good after all contacts were cleaned and sanded rust-free. Good luck (IMG:style_emoticons/default/beerchug.gif)
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Tom
post Apr 28 2008, 11:16 PM
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Found a problem on mine when I had the engine out for cleaning and sealing. The fuse holder on the relay board is rivited to the underside where the trace goes to the next point. The rivet was loose and made contact some of the time. It may even pass an ohmmeter test, and still can break down when asked to pass current. I wire brushed as well as I could, then soldered the fuse holder to the rivet. Been 2 years and no further problem yet.
Tom
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lonnie152
post Apr 29 2008, 10:25 AM
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very much appreciate all the responses. and so i have/will:
1. left a message for sean;
2. bought replacement relays;
3. ask anyone here for detail on wiring around board.
many thanks.
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swl
post Apr 29 2008, 12:51 PM
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CSOB hint #1. If your headlight motors are working you have a source of two known good relays. They are the same as the ones on the relay board. You can just swap them in for the fuel pump and master power relays and know if you need to buy new ones.

CSOB hint #2. Old relays sometime can be brought back to life through terminal cleaning. Perhaps this is a RCSOB hint (IMG:style_emoticons/default/smile.gif)

Probably one of the first things you should check is the fuse block. Remove power from your coil (to avoid the chance of frying your points while troubleshooting). Key on. With Volts selected on your multimeter measure from ground to each side of the fuse - it should be whatever your battery voltage is on both sides of the fuse.
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JeffBowlsby
post Apr 29 2008, 02:49 PM
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Maybe this helps?


Attached File(s)
Attached File  zRareDoc30.pdf ( 7.32k ) Number of downloads: 488
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lonnie152
post Apr 29 2008, 02:51 PM
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thanks for suggestions.

to be precise the black wire that seems to run the pump comes in one side of relay box but exits the other end with no power. we can jump it at the relay to get it to work. but in short that is the problem. so can we just by pass the box ??
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ericread
post Apr 29 2008, 03:05 PM
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QUOTE(Jeff Bowlsby @ Apr 29 2008, 01:49 PM) *

Maybe this helps?


Damn Jeff... You keep coming up with the nost incredible documentation!!! THANKS!
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anderssj
post Apr 29 2008, 03:36 PM
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Maybe this can help tooAttached File  914_electric_73_relay_board_12_pin_connector.doc ( 240k ) Number of downloads: 145
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anderssj
post Apr 29 2008, 03:44 PM
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and this



Attached File(s)
Attached File  914_electric_73_relay_board_14_pin_connector.doc ( 239.5k ) Number of downloads: 106
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swl
post Apr 29 2008, 06:08 PM
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um what engine are we talking about here? DJet or LJet?
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lonnie152
post Apr 30 2008, 10:17 AM
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QUOTE(swl @ Apr 29 2008, 05:08 PM) *

um what engine are we talking about here? DJet or LJet?


i assume since it is a 1974 2.0 it would be a DJET?

also thanks to all for the diagrams, they are great!!!
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swl
post Apr 30 2008, 11:07 AM
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QUOTE(lonnie152 @ Apr 29 2008, 12:51 PM) *

we can jump it at the relay to get it to work.


hmm. You do understand that the pump only runs for a second when you key on. It then stops until the ecu detects that the engine is turning over. You can over ride this by removing the 4 pin plug at the back left of the relay board and jumpering pin 3 to ground. Then the pump will run continuously.
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ericread
post Apr 30 2008, 11:22 AM
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QUOTE(swl @ Apr 30 2008, 10:07 AM) *

QUOTE(lonnie152 @ Apr 29 2008, 12:51 PM) *

we can jump it at the relay to get it to work.


hmm. You do understand that the pump only runs for a second when you key on. It then stops until the ecu detects that the engine is turning over. You can over ride this by removing the 4 pin plug at the back left of the relay board and jumpering pin 3 to ground. Then the pump will run continuously.


Isn't there a negative issue with keeping the fuel pump running continuously? Or maybe not, with the return line providing pressure relief. What are your thoughts?
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lonnie152
post Apr 30 2008, 12:39 PM
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sorry, i have not made it clear that i have converted this car to carbs. also did the switch to correct rotary fuel pump,etc.
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bperry
post Apr 30 2008, 12:54 PM
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QUOTE(lonnie152 @ Apr 30 2008, 01:39 PM) *

sorry, i have not made it clear that i have converted this car to carbs. also did the switch to correct rotary fuel pump,etc.


So maybe you could tell us how you wired this up and what changes you made
in wiring including any jumpers and the location and colors of
all the wires you tapped into.

If we know that, we can easily help you locate where your loss of power is
or offer a simple work around to get you up and going again.

--- bill
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