Had a battery problem, it went so dead it took a reverse polarity
charge on being recharge! Got that straightened out, then replaced a
blown fuse under the dash (10A fuse labeled Power). This fuse must
have blown when I inadvertently tried hooking up the reverse polarity
battery. All other fuses fine. Fuel pump fuse is ok, and fuel pump
can be heard working.
Engine will not start. I checked, it has good high tension at the
plugs. So I'm thinking a fuel delivery/injection problem somewhere.
Any suggestions where to look next will be deeply appreciated.
What fuse was burn? Hope it was not the ECM I or ECM B ;-)
I suppose it is a TBI, are the injectors working?
Remove the air filter cover and check for a mist of gas going out of the
injectors while you crank and listen for a clicking sound. You can also
put a dry rag under the injectors, crank it a few seconds and check if
the rag is soaked with gasoline.
If you got this and you have spark, then it _should_ start.
Next step is to remove a couple of spark plugs to see if they are fouled
with gas or oil.
Good luck. And try to check what fuse was burn, ECM's don't like reverse
I am not a mechanic but that's what I'll do ;-)
Del, are you saying you tried to jumpstart your truck reverse-polarity?
I'd say that could probably cause some havoc...look to the ECM being fried.
If the battery is good, try putting a paperclip in the A&B slots on your
ALDL connector(located by your left knee when sitting, A&B are the
uppermost-right 2 slots). TUrn the key to ON, not START, and see if it makes
your check engine light flash.
It's not a guarantee that your ECM(computer) is good, but it would be more
likely to be functioning properly. Let us know if there are any error codes,
as well. it should flash 3 sets of 12's(one flash=number one, 2 flashes=2, 3
After the 3 12's should follow any stored codes with another set of 12's
indicating the end of the error log.
Thanks, Sam... I think you may be right on the ECM.
In answer to your battery question... have you ever heard of a battery
being so deeply discharged that when finally recharged it is reversed
polarity? I'd heard of it, but never experienced it. Wally world gave
me a new one free of charge (hmmm) since it was less than a year old.
Anyway, this evening I jumped the A & B slots on the ALDL, not getting
the 12 count. Check gauges lite comes on and stays on, but the Check
engine light never ever comes on, jumpered for error code or not.
I also checked each fuse in the fuse block electronically, then
checked the fuseable links under the hood.... all good.
A friend has the same 1500 model '88 silverado, and he'll let me swap
his ECM into my rig to verify your diagnosis.
| > Thanks, Sam... I think you may be right on the ECM.
| > In answer to your battery question... have you ever heard of a
| > being so deeply discharged that when finally recharged it is
| > polarity? I'd heard of it, but never experienced it.
| can't happen
I agree with Gary. The only time I've seen a battery reverse polarity
charged was when some one hooked up a *$%! fast charger to the battery
backwards. Needless to say, things were weird and that battery didn't
Could this have happened here? (Charger hooked up backwards)
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