Billgran wrote:
"Per-Olof Litby" wrote in message
...

Billgran wrote:


A voltage drop test using a voltmeter will tell you where the problem is.
Read a service manual or enlist the help of a knowledgeable person to
perform it.

Bill Grannis
service manager

OK, this thing is giving me gray hairs. I've done the voltage drop test,
and the voltage drop (which varies depending on what you switch on, from a
2-3 volt drop with the cabin lights on to a 6-7 volt drop with the
ignition key in the start position) actually starts at the battery
positive terminal and remains the same at other points forward.

Measuring directly between the battery terminals, the voltage drop is
right there whenever something is switched on.

The trim solenoids (just barely) trigger when a direct lead from the
positive battery terminal is connected to their trigger terminal. The
starter solenoid does not (suspect it needs more current). Doing this
drops the voltage (direct at battery) down to 6 volts.

All ground points (I tested several) have the same potential as the
negative battery terminal, so ground seems fine from that point of view.
The main ground wire from the negative battery terminal to the engine
ground point seems OK, no obvious corrosion or damage.

So this to me indicates either a faulty battery - which seems strange
since I tried a different battery last fall when the problem showed up the
first time and that didn't help - or some problem with the grounding.

Am I correct?




You are not performing a diagnostic voltage drop test. Refer to a service
manual or enlist the help of a knowledgeable person to assist and guide you.

I am not going to type the whole procedure, as that is in many reference
books, but what you want to check using a voltmeter along each section of
wiring and connector sis the voltage drop in that area when under a load.

Good luck, let us know what you find out.

Bill Grannis
service manager



OK, after some more voltage drop measurements and battery tests I
replaced the battery, and for good measure the main ground wire. Now
everything works except the starter - starter solenoid triggers but
starter does not run.

There is a 1.8V drop under starter load across the wire from battery +
to starter and that wire gets very hot so I will replace that wire (old
and corroded) - had no 4 awg wire so will get some tomorrow.

I hope that will solve this final problem and that it isn't the starter.

/POL