The past several times out I have been experiencing intermittent electrical and voltage drop while hitting trim, electric bolsters, tabs or anything. The engines die immediately (2003 525's). Batteries show full voltage 12.7V

Today I was starting to troubleshoot the problem, turned both switches to both, opened the hatch and just did a visual to see if it was anything obvious. I cleaned the terminals on both batteries and went to close the hatch - nothing. No power to the helm. The Voltage meter in the elctrical panel indicated 12.5 Volts and it had power.

I verified the grounds were tight to both engines, verified positive at the starters and tight connections. All ok.

I started with a test light under the helm and as soon as I touched it across the negative terminal strip and the positive terminal strip - I HAD POWER!! Turned the key the power shut off. Did it again, and this time I could crank the engines and had power. It is like I reset something. Is there any main breaker on the Cheetah?

WHAT THE HELL IS GOING ON???? Anyone have an idea? Have a trip planned tomorrow.

Sounds like a bad switch or relay some place. Try and duplicate what you just did with the battery switch. Could be bad one. Does the motor crank over well?

Yes, but only after I turn on the battery switches and put a test light between the neg and pos terminal strips up by the helm.

Sucks!

Look for a cooroded connection feeding power to the helm. Anywhere from the battery forward. Often you can measure adaquate voltage with a meter but then suddenly attempting to draw current through it will result in nothing. Starting from the battery in the faulted condition and using a DVM find the first place with low voltage. There's your bad connection.

I agree Nighthak. It did it 5 times o the trip. I can either wait a few minutes or put a test light across the termina strips and she fired right up. Pain in the A$$.

I will take all teh connections apart from battery switchees to helm, clean them and reassemble. Its going to be that or a semi loose connection on a main cable.

Will keep you posted. Use my frustration for your next electrical issue!!

I am guessing a floating ground of some sort it really does nto make any sence to me with this light thing. The test light is shorting down across pissitive but it does not damage anything because of the light going on. That is why you never use a test light on an air bag car because if you hit the wrong wire you are screwed.

I will sort this out tomorrow!! Its killing me not to be able to find this.

Another thing to do is to use a wire attached to your battery Neg. That will give you a common reference to measure voltage from. Stepping from battery positive all the way up to the dash, look for a drop in voltage. If you can create a load on the circuit, the voltage drop at your bad connection, will be larger and easier to see.
When you put the test light across the Pos and Neg strips at the helm, the small amount of current may help reestablish the circuit, so you can start the motor, but once a load is on that circuit it heats up the connection and drops more voltage, then things go dead. The starter circuit is controlled by a relay, so it doesnt take much current to engage the relay. That would be the only explaination I can think of to cause your symptons.
You have to look at more than just connections, you may have wire that is corroded and it isnt visible. Maybe it got pinched and some moisture got in and then it is down hill from there.
I like to draw a block diagram of the circuit.. Battery, then main terminal in engine compartment, then the helm... What ever is present. Then write down the voltages as you go..
If you have good 12v through out, then move to the positive side of the battery with your reference wire, now step through all the negative side wiring up to your helm.. Again write down the voltages..
Then look at the diagram, sometimes looking at it from a different perspective will show something..

You should find a bad connection on one side or the other.


Good luck, keep us posted.
Dick

Elite how many batteries do you have and do you have them all grounded to the block? Not just running a short neg wire from battery to battery and then the last battery to the block? Also run a new ground wire from the block all the way to the main neg connection in the dash..

Chris

Two batteries both grounded to the blocks.

Mr Gadgets - you are correct, that will be the only way I find this. While I'm at it I'm going to create an eklectrical diagram of my system for future reference!!!

Didnt get to it today, garage cleaning day!