Complete rebuild done, no current getting to dashboard, desperately need help

[quintonwatts]

Hi Guys

I am in the throes of finishing a complete stripdown and rebuild of my AQ205A. I am failry convinced the wiring is OK as I took photos of everything before taking it apart and re-assembled according to the photos. However when I turn the ignition key to first post I would expect to see the dials for the leg kick in, the hour meter start moving and be able to get a backlight to the dials however there is no power whatsoever. BElow is what I can confirm:

- The battery switch is turned on to both (have also tried only 1 for engine).
- Engine battery has reasonable charge reading a little over 12v and has enough power to work all the domestic equipt.
- When I take a volt meter down to the starter motor and put one connection on the positive and the other on the negative (connected to the bell housing) I get a strong 1v reading.


Frankly I have no idea where to start fault diagnosis. Any assistance will be gratefully received as I have spent a fortune in parts and god knows how many hundreds of hours doing this over the past 12 months only to not be able to even TRY firing it up.

 

[Don S]

Re: Complete rebuild done, no current getting to dashboard, desperately need help

- When I take a volt meter down to the starter motor and put one connection on the positive and the other on the negative (connected to the bell housing) I get a strong 1v reading.

Put the red meter lead on the starter terminal A (in picture below) and the black lead on your battery negative terminal and see if you get 12 Volts, if you do, you have a ground problem, if you don't have 12 volts, then you have a problem in the cable or switch between the battery and the starter.

 

[quintonwatts]

Re: Complete rebuild done, no current getting to dashboard, desperately need help

Hi Don, thanks for the reply, the text was meant to read 12v reading at the starter motor. I have dismantled the battery switch and am getting nothing there either. Will try your diagram tomorrow as I have just perforated my eardrum on a cable tie poking out of the side of the enginebay. Lovely!

 

[Don S]

Re: Complete rebuild done, no current getting to dashboard, desperately need help

Ouch, sorry to hear that. Been poked and cut with those things myself. One of my pet peeves is people that don't cut them off, or they cut them at an angle so they cause blood loss.

On to your problem when you get back to it.
There should be a circuit breaker on the engine, check it with a meter, don't just push the button and think it's ok. One note, the wire for power to the breaker comes from the starter, you did get that wire back on the starter when you put the batt cable on didn't you?
Also check at the ignition switch and see if you have power to the switch. There may be a fuse in the wire going to the switch or in the purple wire coming out of the switch.

 

[quintonwatts]

Re: Complete rebuild done, no current getting to dashboard, desperately need help

Hi Don

So, back to this little problem. Have now got a new starter solenoid (over-tightened a terminal and CRACK!). Still no luck on the electrics. It is getting through to the starter solenoid and then on from there to the alternator and hydraulic pump for the leg, as the diagram shows. The issue appears that the red / yellow wire which heads off to the relay / automatic fuse doesnt carry the current and this is what should go on to the dash etc. I am sure I have wired it corretly, see pic, but am at a complete loss as to where to go next.

 

[Don S]

Re: Complete rebuild done, no current getting to dashboard, desperately need help

The relay is the starter slave relay, NOT a fuse or circuit breaker or anything else. Just a slave relay. The relay gets power from the engine and only the control circuit comes from the helm.

Here is a basic diagram that shows how the volvo start and ignition system are wired. (other than the distributor).

Do you have a 12V test light handy?

 

[Don S]

Re: Complete rebuild done, no current getting to dashboard, desperately need help

Have been wanting to re-write the troubleshooting for the starting system for the Volvo's for a while now. This seems as good a place as any to try it out. Your starting system operates exactly like ever other VP engine since yours works. Here goes.

To make this as easy as possible to test out, make yourself a long jumper wire that will clip onto the battery and you can hook your test light to for working under the dash.
Using the picture above in my last post to ID the check points do the following.

Start by checking that you have a good battery that is fully charged. Make sure that all cables have clean tight connections on BOTH ends of the cables, and they are properly sized.
If you don't have this to start with, the rest of these tests are meaningless.

1. Hook your test light ground clip to the A (negative) terminal of the battery. Now touch the point of your test light (TL for short) to the B (positive) battery terminal.
Touch the battery terminals only, not the cable ends (they could be bad too.
Remember how bright that was, all the other tests should be like that. If they get dim, then you have a problem. Now touch the TL to the cable end on the battery cable, TL should light up.

2. Now move to the starter C terminal (again, both terminal and the wire connector) if ok, move on to the circuit breaker.

3. Check both terminals E and F. Don’t assume that just because the breaker isn’t popped that it’s ok. It may be dead inside. TL should light up.

4. Now move to the starter slave relay. Remove the relay and set it aside. Touch your test light to the 30 terminal of the socket. TL should light up.

5. If you have power and ground to the engine, you should be able to use a short jumper between relay socket terminals 30 and 87 and the engine should crank over. If it doesn’t crank over, then the starter or starter solenoid is defective and needs repaired or replaced.

6. Disconnect your TL ground lead and touch it to terminal 86 of the socket, and the TL point to the 30 terminal. This will tell you if the relay has a good ground or not. It should light.

7. Assuming all is good at this point, hook your TL ground clip back to the long jumper BUT, hook that jumper to the B (positive) terminal of the battery, and head for the helm. Going to make sure your negative bus and instruments have good grounds.

8. Under the helm, touch the tip if the TL to your ground bus bar, the light should light up. Also touch the negative terminals on the instruments to make sure they also light the TL.
If all checks out, disconnect the test lead from the Positive terminal of the battery. Keep it handy, you may need it later.

9. Hook the ground clip of the TL to a good ground under the dash. Touch the tip to the B (30) terminal of the ignition switch. You should have a light. If not, then you may have a fuse or a corroded connection between the switch and the engines circuit breaker that checked out good.

10. We will assume the B terminal checked out fine. Turn the ignition key to the run position, touch the TL to the I (15) terminal of the ignition switch. It should light, and you should have power to your instruments. If the TL lights on the I terminal and the instruments do not come to live, then you have a bad connection or a fuse between the ignition switch and the instruments.

11. Now turn the key to the start position and check the S (50) terminal of the ignition switch, it should light. If not, the switch is bad. Turn the ignition switch to off.

12. We will ignore the neutral safety switch at this point and move back to the engine. Clip the ground clip of the test light to a good clean engine ground. Recheck the 30 terminal in the relay to make sure the ground is good and the test light is bright enough. If so, then touch the 85 terminal of the relay socket with the TL and have a helper turn the key switch to start. The TL should light. If it doesn’t, you will need to access the neutral safety switch and jumper the two terminals G and H to and retest at the relay 85 socket terminal. If still no light, then you have a wire connection in the Yellow/red wire bad or the wire itself is bad.

If all the wiring checks out, then you probably need a new relay.

It sounds like a lot, but it only takes about 10 to 15 minutes to check things out and know exactly where the problem is. Once you understand it. First time, expect to take as much time as needed to check things right.

 

[jerryjerry05]

Re: Complete rebuild done, no current getting to dashboard, desperately need help

You have a fuse panel under the dash?
Check fuses?
The lead from the front to the rear?Color?
Try tracing it from the front to the rear.
Maybe broken?
Sometimes the lead is just hooked to the battery and it can get stuck behind the battery and things in the back.

 

[quintonwatts]

Re: Complete rebuild done, no current getting to dashboard, desperately need help

Hey all, thanks for your advice. Turns out the wire going from the positive to the circuit breaker is a black one! Not sure why and I logically had it attached on the negative terminal. So, put it on the positive and hey presto, it has life! This is the second wire like it...the other was black and went from the positive battery terminal to the battery switch. No accounting for folk!

Onwards and upwards!

 

[Don S]

Re: Complete rebuild done, no current getting to dashboard, desperately need help

I think if you look at that black wire to the breaker, you will find it's a red wire with a black sleeve over it.

 

[quintonwatts]

Re: Complete rebuild done, no current getting to dashboard, desperately need help

Thought of that but didn't want to cut into the sleeve as it works. Why do that though?