no voltage on start up

[cfdlighthouse]

Noticed a problem this morning. started the truck and volts around 11. stepped on the gas to get rpms up above 1000 no change. drove about a quarter mile and the volt meter went to 13.

checked the volatage before i left and it was 11.8 once at work checked before turning truck off and it was 13.7.

i have searched here and there seems to be debate about voltage reg vs. alternator problems but no definitive answers or concensus.

Sounds like a voltage reg problem to me but am confused about the instance of alt. producing after being driven and not just from rpms above 1000.

oh i have the internal vr on top of th alt.

Thoughts????????????????????

Thanks in advance
Dan

 

[D'Animal]

Are your battery posts clean and making good contact?

Check the wiring at the alternator itself.

 

[astr]

Also, check he belt that drives the alternator. A loose belt can lead to erratic voltages.

 

[cfdlighthouse]

Are your battery posts clean and making good contact?

yeah i took them off last month cleaned the posts and connectors and sealed them with battery post sealer.

Check the wiring at the alternator itself.

i will check that at lunch

Also, check he belt that drives the alternator. A loose belt can lead to erratic voltages.

belts all were tensioned last week so no slippage

Thanks
Dan

 

[dfmorse]

Also , check the fuse links - kinked, corroded etc will produce weird voltage.

...

 

[jacksfj62]

I have the same problem but only when it is cold outside and am interested in possible causes as well.

 

[cfdlighthouse]

Also , check the fuse links - kinked, corroded etc will produce weird voltage.

...

which links in particular??? not be a smart a** but there are a few!!!

oh checked the connectors at lunch and they are all tight and free of corrosion....

still same issue for the last three start up cycles low voltage drive a short distance and voltage comes up to normal??????

 

[dfmorse]

cd..

The FUSE LINKS are right off the + battery terminal.. But now that u implied fuses, it might be a good idea to pull the fuses, check for corrosion and replace them back in their sockets. That will help with faulty connections. The ignition fuse is one to look for; I don't have the wiring diagram in front of me at the moment, so I don't know how they are laid out.

...

 

[Trollhole]

Long shot but easy to check.

Has happened to me. Rust built up around the Alt mount causing a weak ground.

Get a jumper cable and attach the battery ground to the alt housing. If it fixes the voltage problem I'd say this was your problem.

 

[cfdlighthouse]

Long shot but easy to check.

Has happened to me. Rust built up around the Alt mount causing a weak ground.

Get a jumper cable and attach the battery ground to the alt housing. If it fixes the voltage problem I'd say this was your problem.

that sounds like a great suggestion. would not have thought of it. i will try it once it stops raining