Uremacher

Hello.
C4 corvette 1988 I need help with this issues, I installed an new serpentine belt, I hooked up ground battery cable engine started up immediately, always the first start after battery negative cable hooked up computer turns on the heater temp 75 idles fast until sets up, this did not work I tried to turn the a/c also the heater no power, I checked charging at idle 11.5 amps only I checked fuse panel the 10 amp fuse is blown (gauge circuit # 39)
Could some one help me, thank you.

j-vette

Uhhh, put a new 10 amp fuse in...?

Uremacher

I put anew 10amp (gauge) fuse in as soon as I turned ignition on fuse is blown again. Engine will start charging only at 11.5 amps also unable to turn on heater or a/c inoperative. I will check circuit # 39 next. If anybody can help with this problem please do so, thank you.

jfb

There is no amp gauge in your C4, do you mean 11.5 volts? Working alternators charge the battery with 14.3 volts when cold and this drops to 13.4 volts when the alternator gets to its operating temperature. If your battery really is at 11.5 volts, it is badly discharged and should be charged up at least overnight with a battery charger. The gauges fuse supplies power to 19 devices, defogger relay, vapor cannister purge solenoid, low coolant module, audio alarm module, telltale assembly, LH and RH vanity mirror light, heat a/c programmer, heater a/c control assembly, courtesy light timer, module relay, cruise control brake switch, overdrive relay, air select valves, air divert valves, EGR solenoid. Any of these devices if shorted will blow the gauges fuse, not to mention the wires going to all of these devices could have abraded insulation and is touching ground. One way to check is to put a 12v lamp in place of the fuse which will light to full brilliance if there is a short and then unplug each of these 19 devices one at a time to see if the light goes out. If it doesn't, then you will have to trace each wire to these devices to see if a wire is bare or pinched and shorted to ground. Best buy the electrical diagnosis manual for your 88 as it describes where all of the connectors are and where each device is located.

Uremacher

Thank you for this information, I am in process of checking all items you mentioned. I had my alternator on the tester it is OK my battery is 2 years old I purchased a new one. My ABS light is on I will investigate this issue next. Thank you again for your help.
Regards,
John

Hot Rod Roy

John has probably solved his problem. That was 9 years ago!

PastorDavid

Glad this is here, having the same problem on my 90, will check all of these things out.

Uremacher did you ever get it figured out?

CorvetteRules

OP has not been on site for 2010 So my guess is we will never find out.

Sabre34

I agree. It may be time to start a new thread on this topic. Thread closed.