electrical troubles

[michel richard]

Here's another test to the knowledge of 914 experts.

I rebuilt my 2.0 1973 engine and I now have the following problem, which may or may not be actually related to the rebuild.

Right after the rebuild the engine would crank allright but did not catch. I had a spark and fuel pressure so that I figured the problem was in the injection system.

I went through Kjell's paper, I checked continuity in the whole wiring harness, I checked continuity on the relay board, all was fine. I finally figured that the whole injection system was not getting any power, so that the relay for this system became a prime suspect.

So . . . I ra a jumper wire from the ignition coil to the plug on the relay board where the ignition system gets its power, and it fired !

The only thing is that turning the key to off did not then kill the engine. I had to unplug the jumper for that to happen. I then got a new relay but I still needed the jumper to get the engine going, except that turning the key off now stopped the engine.

I am now back tot eh original situation, where I need to unplug the jumper to stop the engine. I don't know if I fried the relay or simply mixed them up but that is where I'm at.

Any help would be appreciated.

Regards.

[Wayne 962]

Hi there. This is an interesting problem.

I would start by troubleshooting your relays and your relay board. Check to make sure that every contact is operating correctly. Use a multi-tester and check the board with the power off, and then with the power on. This will tell you if you have any problems with the relays too. For reference, use the electrical diagram of the 914 relay board:

http://www.pelicanparts.com/914/parts/Electrical/electrical_1971relay.htm

Hope this helps,

Wayne

[Dave at Pelican Parts]

If you want to check a particular round relay's functioning, just swap it with one of your headlight relays. If the headlight will go up and down, the relay is fine. This assumes that your headlights are working OK, of course.

It sounds as if you might not have power getting to some part of the relay board. Use the diagram that Wayne mentioned, or the somewhat harder-to-read one from the Haynes book (at $15, it's well worth it!) to see what relay pins connect to which wire terminal pins. Most of the power coming into the board comes in through the "T-14" terminal at the right-front side.

Check the wiring diagram for your year of car to see which wires should have power when the ignition is on. Most of those wires will be red with a black stripe, or black with or without red stripe. They'll be coming from the ignition switch, probably through the fuse panel.

Also check which wires go to the two side terminals on the relay. Remember that, for the relay to switch, it needs power on one side and ground on the other.

Good luck!

--DD

[michel richard]

Bingo !

Well, I went through a few things. I checked my relays, using the headlights, and there was one that was no good, so I used the replacement I had borrowed.

Next, I followed the suggestion that the part of the board was not getting juice and scratched my head for a bit looking at the wire diagrams.

Then I saw that the red wire that goes from terminal 14 at the top of the board direct to the battery was broken right at the battery post. I had not noticed because is was still in position, it was just broken and was not touching.

So . . . as a temporary fix, I taped it up tight and the problems are gone !

All i have left to do in that regard is find a way to crimp the wire correctly. I don't have a lot of lenght to use though, but I'll figure it out.

Thank you very much, Wayne and Dave, I could not have figured it out without you pointing me in the right direction.

Rolling in Montreal,

Michel Richard.

[JP Noonan]

My harness was aready hacked up using ring terminals, so originallity was not a concern. Here is what I did.... I took the 7-8 gauge wire from a 72 harness that went to the ing. switch along with the two 10-12 gauge wires that went to the relay board and fused them. I used a marine 4 fuse fuse block, one 30 amp to each of the 10 gauge wires and two 30 amp fuses in paralell to the 7 gauge wire. The batt. terminal wire looked old so I used a genaric 54" (??? maybe more maybe less) NAPA positive lead from the batt. to the starter. From the fuse block to the batt. I used ring terminals that fit the trhu bolt on the lead terminal. Not rocket sience, I'm sure you could have figured it out on your own, but I hope this helps. I didn't like the idea of all those wires off the battery with no fuses. Both my 74 and my 72 parts car had evidence of wiring harness fires, so call me paranoid.