Heater, gauges, and radio all stopped working! Help please! (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Mar 10, 2018
Threads
1
Messages
7
Location
Bonita springs, FL USA
My 1978 fj40 radio (aftermarket) went out. Then I looked down and my gauges (oil, temp, fuel) were all going down to zero. The truck runs perfectly fine other than that. The first thing I did was check the fuses and the heater fuse was blown. I replaced that, checked all the other fuses with a meter and tried again. I don't know if it's pertinent, but the seldom used heater sometimes needed to be turned off then on to get to blow. Anyway, still no gauges, radio, or heater. What am I missing? Some forums mention the heater blower motor resistor (which I ordered), but that only seems to be for temp and fuel gauges. There's no other problems or malfunctioning electronics. If this has been posted before, can you post the link?
 
As @RustyRanger said, it sounds like a bad ground.

The heater and radio have their own fuses, on a '78... I'd disconnect the battery, pull the fuse box, clean all the contacts and reinstall it... check continuity on all fuses before you reinsert them... they can be bad and look good.

The large (8ga) WL (white, with blue stripe) splits near the gauge cluster... one branch to the fuse box and one branch to the cluster. Note: be sure you never remove the cluster without disconnecting the battery.

I think @Racer65 still sells new fuse boxes and new fuse box covers, if yours' is too knarly.

BTW, the fuse box has it's own ground to the body, near the fuse box, you may need to clean that ground and make sure it's grounding to bare metal
 
I checked all the grounds, cleaned them and tightened/reconnected an aftermarket ground and it seems to work! Thanks everybody for the help! I'm hoping to take it to the Florida Keys in a few weeks... Hopefully all the kinks are worked out! It's running great!
 

Users who are viewing this thread

Back
Top Bottom